texts:
gdal_polygonize converts whatever rasters values into vector integers as it is based on the GDALPolygonize() function (http://gdal.org/gdal__alg_8h.html#a3f522a9035d3512b5d414fb4752671b1).

It is suggested that the GDALFPolygonize() function (http://gdal.org/gdal__alg_8h.html#a7a789015334d677afcbef67e5a6b4a7c) should be employed in case floating points are to be transferred.

However, it is absolutely obscure to me how to implement or call such function instead of the standard one. No clue is available anywhere.

I'm calling gdal using both OSGeo4W shell as well as QGIS2.6 python interface (I'm on Windows 7 and 8.1).


texts: OSM to OGR - Stream or File - install missing driver

texts:
I'm trying to convert a .osm-file or overpass stream (both XML-based) into OGR conform layers. I already found an approach which should work:

https://pcjericks.github.io/py-gdalogr-cookbook/vector_layers.html#get-a-list-of-the-street-names-in-a-osm-file

But ogr.Open returns an Nonetype element. Is there any way, I can install the OSM driver into my OGR/GDAL setting?

My configuration:

Windows 10 x64 - Python 2.7 32bit (because of Arcgis 10.4)
GDAL Version 2.1.0
OGR Version 2.0.12


texts: ogr2ogr apply sqlite dialect to multiple feature classes within a fgdb

texts:
I have a quite many feature classes in a filegdb and they all have same data schema (same field names and etc).

I wanted to apply a single sqlite query and I am having hard time to make a loop command

  ogr2ogr -f "filegdb" -a_srs epsg:3857 -dialect sqlite -sql "select scalecoords(geometry,0.0000000002), field1, field2, field3 from "FEATURE_CLASSES_WITHIN_A_FILEGDB" "inputGDB_Dir"  "outputGDB_Dir"

what I did was simply applying

  For /R %g in (inputGDB_Dir) do ogr2ogr -f "filegdb" -a_srs epsg:3857 -dialect sqlite -sql "select scalecoords(geometry,0.0000000002), field1, field2, field3" "inputGDB_Dir %g"  "outputGDB_Dir"

and obviously, it does not work.
I would like to know how to make a loop command using OGR2OGR


texts: Howto "Enable feature simplification for newly added layers" with PyQGIS

texts:
Having some performance issues getting huge vector layers to be drawn the first time under heavy system load, I am interested to test what is called in QGIS application "Enable feature simplification by default for newly added layers" from the QGIS settings menu.

What is the PyQGIS equivalent to the QGIS setting? Is there a setting for individual layers only?

I am required to use PyQGIS 2.8 on Linux.


texts:
I performed with grass QGIS processing tool "r.regression line" a linear regression between two rasters.
The result I got is shown in the picture

Can someone explain to me what is the meaning of the value of F?
I couldn't find it on internet


texts: License Distirbution of modified QGIS and Plugins

texts:
My company (public service) developed a modified QGIS and QGIS-Plugins for crisis units. Some of the Plugins are self developed and some of them are modified from already existing QGIS-Plugins. All of them a licensed by GNU.

Our plan is to distribute the Software on a free available Website. So everybody can download the software there. Would this be enough to comply with the GNU/GPL License conditions? Or do we need to share the Software and the Plug-Ins on another platform?


texts:
I'd like to know how (if possible) to transform the shapefiles I've downloaded from the natural earth datasets which are in EPSG:4326 to BNG EPSG:27700.

So far I've loaded the shapefiles I need into a Postgresql database through the Postgis shapefile loader. Normally I would have the data stored as separate lat/lng columns and run a query such as..

UPDATE table_name
    SET geom_column = ST_SetSRID(ST_MakePoint(wgslng,wgslat),27700);

This time however the files are not supplied with lat/lng only a geom column in 4326. I'm using the populated places, coastlines, land, ocean and urban areas shp files.

Is there a method that would allow me to transform the 4326 geom column to 27700? I need the data in BNG so as I can measure distances in metres.


texts: Splitting polygons based on points density

texts:
I have a geojson file with polygons representing administrative regions.

I also have a shapefile from which I can extract a list of points of interest (schools).

I can iterate over this list of points, and for each point, check what polygon it falls within, and assign it to that polygon.

I then want to split each polygon into two, with the size of each child polygon inversely proportional to the number of points falling within that child polygon.

For example, I have polygon A, which contains 5 points. The area of this polygon is 5 square kilometers.

I want to split this polygon into two smaller polygons B and C, such that B will have a size of 2 square kilometers and contain 3 points, and C a size of 3 square kilometers.

Once I'm able to do this, I think I should be able to accomplish what I'm trying to do: I ultimately want to split up each polygon, representing an administrative region, into many smaller polygons/administrative regions.

The idea is that denser areas will have more administrative regions compared to less dense ones.

An analogy I'd give is: if I have polygons representing counties, and points representing schools, I want to divide each county into zones such that each zone has roughly roughly 10 schools. Which means that denser areas will have more/smaller zones.

If I'm able to split a polygon into two with the size of each child polygon inversely proportional to points assigned to it, I think I can recursively keep splitting polygons until I get to a specific minimum number of points per child polygon.


texts: Transforming data from GCS Krasovsky to GCS WGS84?

texts:
I am having trouble transforming data from GCS_Krasovsky_1940 to GCS_WGS_1984 in ArcGIS 10.4.1. I'm using the Project tool, but the geographic transformation parameter is left empty and I would expect this to be necessary to carry out the operation. If I run the transformation with the parameter remaining empty the resulting layer has the WGS84 coordinate system, but I do not trust that this is correct.

I read that the GCS_Krasovsky_1940 is really a spheroid and not a datum - is this important in this case?


texts: Visible altitude across a raster from a point

texts:
I have a raster surface model and I'm trying to determine the height an object would need to be at to be visible from an arbitrary point at an arbitrary altitude.

I am currently using Grass and have tried r.viewshed, while it does seem to be able to generate an elevation delta between the raster and the observer, I do not see a way to generate a delta between the raster and the line of sight at every point. my expectation is that everything that is directly visible would have a value of 0, and then shadowed areas would indicate the  minimum height an object would be visible at.

While I am using GRASS at the moment, I am not against considering another piece of software.

Anybody have any ideas? or am I going to have to pull the source for viewshed and modify it?


texts:
I have a GeoJSON representing a fantasy world, with coordinates ranging from -3000 to 3000.
I have successfully displayed it on a Leaflet map using L.CRS.simple, but the GeoJSON is too heavy and takes too much time to load / requires too much memory.
I would like to convert the GeoJSON to vector tiles but I don't know of any tile server that would allow me to load tiles that are not in EPSG 4326 or 3857.
How could I create such tiles and render them on my map in CRS.simple?
I have tried scaling the coordinates with geopandas, to fit in the WGS84 coordinate bounds, but when loaded into something like Mapbox, it gets deformed as you get far from the "equator".


texts: Performing Inverse Distance Weighted (IDW) interpolation in Google Earth Engine?

texts: I would like to know if interpolation like in the image below is possible to produce in earth engine. Can someone tell how to get it done because I can only do it in ArcGIS and QGIS. I found this https://developers.google.com/earth-engine/interpolation but I don't think it's the right one because I have a map, and precipitation in points.


texts:
I have a map service on a local server (marked 2) and a raster (marked1).

I want to add the raster to the service, ovewriting the existing data. To do so I right click the map service in the catalog choose Mange Cache, then Mange TilesIn Update Mode I select RECREATE_ALL_TILES and set the area of interest to the extent of the raster's extent.
Nothing happens, am I doing something wrong?


texts: PHP examples to replicate FeatureServer capabilities

texts:
I used FeatureServer before and I liked it. The only thing I didn't like, though, is that it needs some other dependencies to work. That's why I want to try PHP instead.

I know that there are already ways to get e.g. geojson after query pgsql db with php and pg (like here and here). I think they are good starting points, but I am searching some other good materials with good examples (not only the PHP tutorial like here) to start with.

Any pointers are welcomed, thanks in advance,

PS. PHP to be used with postgis+pgsql+mapserver+geoext+ext+ol


texts: Problem with Viewshed analysis in ArcObjects

texts:
I want to execute the Visibility Analysis Tool using ArcObjects 10.3. I tested the tool in ArcMap and it works great with the test data I provided, hence it should work as well in ArcObjects code. The only difference is that I don't want to write the output raster to file, I would prefer to have it stored in memory for some immediate pixel analysis.
So, please take a look at my code:

private IFeatureClass OpenShapeFile(string shapeFilePath)
{
    string shapeFile = System.IO.Path.GetFileNameWithoutExtension(shapeFilePath);
    string fileFolder = System.IO.Path.GetDirectoryName(shapeFilePath);
    IWorkspaceFactory workspaceFactory = new ShapefileWorkspaceFactory();

    IFeatureWorkspace featureWorkspace = (IFeatureWorkspace)workspaceFactory.OpenFromFile(fileFolder, 0);
    IFeatureClass featureClass = featureWorkspace.OpenFeatureClass(shapeFile);
    return featureClass;
}
public bool PerformAnalysis(string inputRaster, string observerLocationShp)
{
    if (InitLicense())
    {
        //var inputRaster = @"C:\Test\kand_lidar_dem_sub_products.dat";
        //var observerLocationShp= @"C:\Test\VisTest_ObserverPoint.shp"; //feature class with observer location
        try
        {
            ESRI.ArcGIS.Geoprocessor.Geoprocessor gp = new ESRI.ArcGIS.Geoprocessor.Geoprocessor();
            gp.ResetEnvironments();
            gp.OverwriteOutput = true;
            gp.RegisterGeoProcessorEvents((IGeoProcessorEvents)new GPEvents());

            var test2 = new RasterDataset();
            test2.OpenFromFile(inputRaster);

            var testShp = OpenShapeFile(observerLocationShp);

            var output = new RasterDataset();
            output.CreateDefaultRaster();

            Viewshed viewshed = new Viewshed(test2, testShp, output);
            IGeoProcessorResult2 result = gp.Execute(viewshed, null) as IGeoProcessorResult2;
            IGPMessages msgs = result.GetResultMessages();
            var gpInfo = string.Empty;
            for (int i = 0; i < msgs.Count; i++)
            {
                //Console.WriteLine("{0} {1}", msgs.GetMessage(i).Description, msgs.GetMessage(i).Type);
                gpInfo+=msgs.GetMessage(i).Description+" "+ msgs.GetMessage(i).Type+"\n";
            }
        }
        catch (COMException ex)
        {
            Console.WriteLine(ex.Message);
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }
    }
    return false;
}

The code fails on line: IGeoProcessorResult2 result = gp.Execute(viewshed, null) as IGeoProcessorResult2;

The problem is, the GeoProcessor crashes on Execute function giving me the error code -2147467259. I can't see this error code on the list provided by Esri http://help.arcgis.com/en/sdk/10.0/java_ao_adf/conceptualhelp/engine/index.html#//000100000312000000.

In the console output I can see "ToolboxChange" message written two times. Since there are no Console.Writeline functions used in my code, I assume that is what GeoProcessor outputs.

Update: As Hornbydd suggested, I changed the output to file and it works. The problem is, I would like to get a result in memory without writing to file. Is it possible?


texts: ERROR in Resolution Merge using ERDAS IMAGINE 2013

texts: I have attached an example image to show the problem: When i have to Resolution Merge, it will come error this process. How to solve this problem? I would like some suggestions regarding this error.


texts: How to show vector features in OpenLayers after hiding it?

texts:
I did change some vector features style (through check-boxes) using style property :

var features = layer.features;

for( var i = 0; i < features.length; i++ ) {
  //features[i].style = { visibility: 'hidden' };
    features[i].style = 'none';
}

layer.redraw();

But now if I check the box again, it supposed to display again but nothing happens! I tried:

     features[i].style = 'block';
OR
     features[i].style = 'delete';

then redraw the layer.. but this doesn't work

Any Idea ?


texts: Removing additional symbols on single points in ArcGIS Desktop?

texts:
I have problems with a point data layer in ArcGIS (9.3). An additional symbol has appeared on some of the points within the layer which were recently created and checked-in from ArcPad.  This additional symbol cannot be edited and has been placed on top of another symbol which I can edit normally using layer properties.  I would like to remove the additional symbol and retain a single editable symbol for each point.

I have checked the map as suggested in the answer below and have multiple symbols on single points in a single layer. How do I remove the multiple symbols and return to a single editable symbol?

The screenshot below shows an extract from the map (of trees).  The blue circle is the editable symbol covering all points in the layer.  The green circle is the additional non-editable symbol which has appeared for the most recently checked-in points.  I have selected two points labelled Betula and Quercus.  The selected point labelled Quercus has an additional green circle symbol, although that is not shown due to the selection highlighting.


texts: ArcGIS Pro Add-In, MVVM getting filepath in viewmodel but showing only filename in view

texts:
I have an ArcGIS Pro Addin that I need to get a path to gdb for some processing, I would like to do this but show only gdb name in text box. I have a behaviors class and a viewmodel and a view. I tried catching the name as a property in the behaviors class but I am not getting the value when I bind to a text box to check for output.
Here is the browser dialog

namespace BasemapCreator.Behaviors
{
    public class FolderDialogBehavior:Behavior<System.Windows.Controls.Button>
    {

        public void FolderBrowserDialog()
        {

        }
        public string SetterName { get; set; }

        protected override void OnAttached()
        {
            base.OnAttached();
            AssociatedObject.Click += OnClick;
        }
        protected override void OnDetaching()
        {

            AssociatedObject.Click -= OnClick;
        }
        private void OnClick(object sender, RoutedEventArgs e)
        {

            var dialog = new FolderBrowserDialog();
            var result = dialog.ShowDialog();
            if (result == DialogResult.OK && AssociatedObject.DataContext != null)
            {
                var propertyInfo = AssociatedObject.DataContext.GetType().GetProperties(System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.Public)
                    .Where(p => p.CanRead && p.CanWrite)
                    .First(p => p.Name.Equals(SetterName));

                string dirName = new DirectoryInfo(dialog.SelectedPath).Name;
                FolderName = dirName;
                _fileName = System.IO.Path.GetFileName(dirName);
                FileName = _fileName;
                ArcGIS.Desktop.Framework.Dialogs.MessageBox.Show(FileName.ToString());
                propertyInfo.SetValue(AssociatedObject.DataContext, dialog.SelectedPath, null);
            }
        }
        private string _folderName;
        public string FolderName
        {
            get { return _folderName; }
            set
            {
                if (value != _folderName )
                {
                    _folderName = value;
                    OnPropertyChanged("FolderName");
                }
            }

        }
        private string _fileName;
        public string FileName
        {
            get { return _fileName; }
            set
            {
                if (_fileName != value)
                {
                    _fileName = value;
                    OnPropertyChanged("FileName");
                }
            }

        }
        private string _styleName;
        public string StyleName
        {
            get { return _styleName; }
            set
            {
                if (_styleName != value)
                {
                    _styleName = value;
                    OnPropertyChanged("StyleName");
                }
            }
        }

        private void OnPropertyChanged(string propertyname)
        {
            OnPropertyChanged(new PropertyChangedEventArgs(propertyname));
        }

        public event PropertyChangedEventHandler PropertyChanged;

        private void OnPropertyChanged(PropertyChangedEventArgs args)
        {
            var handler = PropertyChanged;
            if (handler != null)
                handler(this, args);
        }

    }
}

Here is the Binding in the View

<TextBox x:Name="gdbName" HorizontalAlignment="Left" Height="30" Margin="56,29,0,0"  Text="{Binding FolderName, Mode=TwoWay}" VerticalAlignment="Top" Width="282" AllowDrop="True">
        </TextBox>

And in the ViewModel I have the FolderName property

private string _folderName;
        public string FolderName
        {
            get { return _folderName; }
            set
            {
                _folderName = value;
                OnPropertyChanged("FolderName");
            }
        }

everything works but the pathnames are so long that sometimes they are hidden. I would like to show gdb name and pass complete path.


texts: is there a way to automate symbology in ArcGIS?

texts:
I would like to know if there is some way to automate symbology based on my attributes. I have a list of zipcodes and a column which contains ID-codes of waterstations delivering water in that area. If zipcodes only have one water station delivering water, the column is filled with one ID. But some zip codes have several water stations delivering there. The column cell is then filled with several ID's (see image). Is there a way to give a specific color to an ID? For instance: ID 32.06 gets a brown color, ID 32.09 gets a yellow color. If a zip codes have both stations, the polygons fills a mix of yellow and brown lines. If a zipcode has only one of the two, it fills the polygon with either brown or yellow (see image).

I can do this manually but there are over 400 possibilities which makes this a very time consuming activity.


texts:
Looking to add my own marker. I have an Icon in SVG format that I would like to use.
Using QGIS 3.4.4


texts:
I have read many tips for the problem "layer becomes cloudy when zoom", but it doesn't work still. Where is the problem in my source?

var wms = new OpenLayers.Layer.WMS( "Földrengések",
    'http:/....../wms',
    {
      layers: ['rengesekk'],
      isBaseLayer: false,
      transparent: true,
      srs: "EPSG:4612",
      numZoomLevels: 12,
    },
    { singleTile: true
    });


texts:
I am working on an app that displays a map. I have the code opening the webMap I have on ArcGIS.com.

In the method

-(void)webMapDidLoad:(AGSWebMap *)webMap

I set an envelope and then call

[self.mapView zoomToEnvelope:env animated:YES];

But the map just zooms to its normal extent, rather than the one I specified. I can't quite  figure out what I am doing wrong.


texts:
I installed QGIS Server 32 bit through OSGeo4W as a localhost service on my Windows machine as of underdarks tutorial QGIS Server on Windows7

I do get my wms up and running but I'm a bit confused as to why it seems to swap the coordinates as shown in the pictures below.

In QGIS

As WMS from QGIS Server

Any clues are welcome!


texts: How to create a raster layer from NetCDF file having multiple variable with multiple dimensions?

texts:
I have a single NetCDF file which has 3 variables named temperature, salinity and pressure and each of these variable have 3 dimensions which are lat,long and time. I want to display this file as a raster layer  in ArcGIS Pro 2.7.3 but when I simply import it using multidimensional raster layer and using any of the output configurations, it displays nothing. How can I display it properly so I can publish it as a service (which I know already)?
I am able to display files having a single variable.


texts: TINs: What advantage does unequal sampling of data points have over regular sampling?

texts: Triangulated Irregular Networks. Under what conditions is one sampling method more appropriate over the other?


texts: Adding EPSG:3857 / 900913 to Oracle's mdsys.cs_srs

texts:
I am working with an Oracle Standard database at version 11.2.0.1.0. I also have access to XE version 11.2.0.2.0.

The later version has both SRIDs 900913 (Google Mercator) and 3857 (official Web Mercator), but the earlier version does not. I read that SRSs are easily inserted into Oracle's mdsys.cs_srs table, so I selected the values for 900913 from the later DB and inserted into the earlier DB.

The insert reported success, but no matter how many times I update it the WKTEXT3D field in 11.2.0.1.0 remains null. If I try a coordinate transformation from a single point (both 2D and 3D) in 4326 (WGS84 Lat/Lon) to 900913 I am told "Parsing error on source or destination coordinate system WKT, or incompatible coordinate systems", then "Check the validity of the WKT for table entries, and check if the requested transformation is valid".

I can use the same transformation query (below) in 11.2.0.2.0 without issue.

Does anyone know

Why the WKT extracted from 11.2.0.2.0 doesn't seem valid in 11.2.0.1.0?
How I can adjust it to make it valid?
If there is some fundamental issue in 11.2.0.1.0 that makes this transformation invalid?

Any input on these issues verrrrrry much appreciated.

Edit: Following MelitaKennedy's suggestion I started trying to track down the 'Popular Visualisation Pseudo-Mercator' projection in my 11.2.0.2.0 DB and I think I found it in MDSYS.SDO_COORD_OPS. However, it references a COORD_OP_METHOD_ID (MDSYS.SDO_COORD_OP_METHODS table) which defines several 'methods'. I assume that each of these methods relates to a function within Oracle, so maybe it simply isn't possible to create the entire CRS / Projection package in a pre-11.2.0.2.0 DB?

Transform Query:

  select
    sdo_cs.transform(
      sdo_geometry(
        2001,
        4326,
        null,
        sdo_elem_info_array(1,1,1),
        sdo_ordinate_array(-132.525665, 45.432552)
      ),
      sdo_dim_array(
          sdo_dim_element('LONG', -180.0, 180.0, 0.5),
          sdo_dim_element('LAT', -90, 90, 0.5)
      ),
    900913)
  from
    dual;

900913 Insert:

insert into mdsys.cs_srs (cs_name, srid, auth_srid, wktext, wktext3d)
  values (
    'Google Mercator',
    900913,
    900913,
    'PROJCS["Google Mercator", GEOGCS [ "WGS 84", DATUM ["World Geodetic System 1984 (EPSG ID 6326)", SPHEROID ["WGS 84 (EPSG ID 7030)", 6378137.0, 298.257223563]], PRIMEM [ "Greenwich", 0.000000 ], UNIT ["Decimal Degree", 0.0174532925199433]], PROJECTION ["Popular Visualisation Pseudo-Mercator"], PARAMETER ["Latitude_of_origin", 0.0], PARAMETER ["Central_Meridian", 0.0], PARAMETER ["False_Easting", 0.0], PARAMETER ["False_Northing", 0.0], UNIT ["Meter", 1.0]]',
    'PROJCS["Google Mercator", GEOGCS["WGS 84", DATUM["World Geodetic System 1984", SPHEROID["WGS 84", 6378137.0, 298.257223563, AUTHORITY["EPSG", "7030"]], TOWGS84[0, 0, 0, 0, 0, 0, 0], AUTHORITY["EPSG", "6326"]], PRIMEM["Greenwich", 0.000000, AUTHORITY["EPSG","8901"]], UNIT["degree (supplier to define representation)", 0.0174532925199433, AUTHORITY["EPSG", "9122"]], AXIS["Lat", NORTH], AXIS["Long", EAST], AUTHORITY["EPSG", "4326"]], PROJECTION ["Popular Visualisation Pseudo-Mercator"], PARAMETER ["Latitude_of_origin", 0.0], PARAMETER ["Central_Meridian", 0.0], PARAMETER ["False_Easting", 0.0], PARAMETER ["False_Northing", 0.0], UNIT["metre", 1.0, AUTHORITY["EPSG", "9001"]], AXIS["X", EAST], AXIS["Y", NORTH], AUTHORITY["", "900913"]]'
  );


texts: Adjective meaning "of the same resolution and extent"

texts: Is there a word that can be used to describe two or more raster grids having the same resolution and extent? I'm fishing around with words like "coincident" and "coextensive," but nothing feels quite right. And I'd rather find something more compact than "rasters of the same extent and resolution".


texts: Selecting points that fall within classified(?) raster

texts:
I am trying to complete an analysis that assesses the likelihood of fire.

From literature I have found that fire is most likely in south facing slopes and least likely in North facing.

Datasets I was planning on using are fire events and aspect. I have currently performed aspect analysis (spatial analyst) on DEM and reclassified the values so each of the 9 directions (N, NE, E, SE, S, SW, W, NW, Flat) have a unique value.

I thought I would then be able to convert raster to polygon then select by location the fire events in each direction - however that does not work.

Are there any suggestions of how i could analyse the number of fire events in each aspect.

(Fire events are points, and aspect raster)

Error Message for extract multivalues to point


texts:
I have a bunch of polygon data that I want users to be able to sort/filter based on certain criteria.

I have the data in a CartoDB table, and can pretty easily use some SQL calls to achieve what I want.  The only problem is that my CartoDB table has to be set to public for this to work, meaning someone could dump the data from my table pretty easily.

So I'm wondering if there's some way I can send the polygon data from CartoDB into some other service, which could filter the query/filter data without opening up my table?

My apologies if this question isn't clear..


texts: Failed to activate Schematics on ArcGIS for Server?

texts:
I am trying to activate Schematics in ArcGIS 10.2 for Server's Capabilities.

After I click "Save and Restart" button, it throw an error message :

  Schematic Server Extension is not supported with the current license.

Here's a screenshot for ArcGIS Server Software Authorization.


texts:
I'm trying to model the great lakes bathymetric data for a cnc. I'm using Qgis to handle the conversion

The Geotiff was obtained from https://www.ngdc.noaa.gov/mgg/greatlakes/erie.html

using the raster calculator I removed the elevation above 0
("erie@1" <= 0)*"erie@1"

which gave me

I've tried using DEMto3d plugin to generate the stl file, but I can't get it to look like the raster in qgis

I have tried increasing the exaggeration factor in the plugin (demto3d) to 10 and even used the raster calculator to exaggerate the the raster file before converting.
"erie@1"*100

Any suggestions?


texts: Polygonize, Polylines to Polygons, and Dangling Ends

texts:
I am a little new to QGIS (using v.2.18.0 La Palma) so perhaps someone can help me out. I am trying to find some faulty topology and understand the conversion from polylines to polygons.

I created five shapes with polylines in QGIS to demonstrate the problem and issues. I intended to post images demonstrating the issues I am having. However, this question/message board will only allow me to post two links. So, unfortunately, my description below will not be quite as clear as it would have been had I been able to post the images I can't post. You will have to go to the link at the bottom of the page to see all of the images.

In the images you will find the following shapes:

Upper Left: 1 polyline (closed)
Upper Right: 12 polylines (closed)
Middle: 17 polylines (closed but complex with many vertices)
Lower Left: 1 polyline (open)
Lower Right: 4 polylines (open)

The middle shape is really the one I am trying to convert to a polygon using either the Polygonize or Lines to Polygons tool, neither which seems to work for me. I ran the Topology Checker to look for dangling ends and the results are shown in the image below taken from a screenshot (dangling ends shown with red dots). I expected errors on the lower shapes because I know they have open ends. However, I cannot figure out why the middle shape has dangling end errors. I have snapped the ends of the lines together and when I zoom in, I cannot find any overshoots or undershoots. What else would cause the dangling end errors?

I ran both the Polygonize Tool and the Lines to Polygons Tool on these shapes. For the Polygonize Tool, both the upper closed shapes create polygons, regardless of whether they consist of one polyline or 12 polylines. The lower open shapes do not create polygons, though that doesn't surprise me. The middle shape also does not create a polygon, which I assume has something to do with the "dangling ends" errors that I can't find.

For the Lines To Polygons tool, only the shapes with one polyline are converted, regardless of whether it is closed or open. The shapes with multiple polylines do not convert, though I don't know why the closed shape in the upper right will not convert. I am at a loss to explain the partial results for the middle shape other than I presume it has something to do with the dangling ends I can't find.

The images I couldn't post and a zip file containing the QGIS project file and .shp file that created the above images can be found here: http://brucewiland.com/download/

Can anyone tell me how to find and correct the errors in the middle shape that would allow it to be converted to a polygon?

I would also be interested in how and why the Polygonize and Polylines to Polygon tools give different results i.e.when do you use one over the other?


texts:
I am using Data Driven Pages to create a set of maps showing locations I intend on visiting (forestry in a city). For navigation purposes my map shows the same location at 3 different scales, close, far and further.

How to get main data frame - the one the data driven pages are based on, to zoom to the extent of the record it is based on? Currently it is set to a fixed scale.

I have to go through my maps to adjust this data frame to fit the largest of the polygons and the rest are automatically set to this scale - but why can this not be automatically zoomed to the Polygone it is base on?


texts:
I have a large dataset of global .nc files and I am trying to clip them to a smaller area. I have this area stored as a .shp file.
I have tried using GDAL from QGIS but needs to do this by converting each variable and I must select each variable and same shape for all files one by one and with 400 files going trough each variable seems not the best idea. Also this returns .tiff files separated and not the .nc file that I am aiming for.
I had this little script but its not doing what I need:
import glob
import subprocess
import os

Shapefile = 'NHAF-250m.shp'

# Create output directory
OutDir = './Clipped_Rasters/'
if not os.path.exists(OutDir):
    os.makedirs(OutDir)

for Image in ImageList:
    print('Processing ' + Image)

    OutImage = OutDir + Image.replace('.nc', '_BurnedArea_Clipped.tif') # Defines Output Image

    # Clip image
    subprocess.call('gdalwarp -q -cutline /Users/path/to/file/NHAF-250-vector/ -tr 0.25 0.25 -of GTiff NETCDF:'+Image+":burned_area "+OutImage, shell=True)

    print('Done.' + '\n')

print('All images processed.')

I have also tried with
import geopandas
import xarray
import rasterio
import glob

shapefile = 'NHAF-250m.shp'

def shapefile_mask(shapefile) -> np.array:

    import pyproj

        with fiona.open(shapefile, 'r') as src:
            collection = list(src)
            geometries = []
            for feature in collection:
                geom = shape(feature['geometry'])
                geometries.append(geom)
            mask = geometry_mask(
                geometries,
                out_shape=(1440, 720),
                transform=(1.0, 0.0, 0.0, 0.0, 1.0, 0.0),
                all_touched=True,
                invert=True)
            shape_mask = xarray.DataArray(mask , dims=("lon", "lat"))
            return shape_mask

    ImageList = sorted(glob.glob('*.nc'))
    print('number of images to process: ', len(ImageList))

shape_mask = shapefile_mask(shapefile)

file_list = sorted(glob.glob('*.nc'))

for file in file_list:
    nc_file = xarray.open_dataset(file)
    # Then apply the mask
    masked_netcdf_file = nc_file.where(shape_mask == True, drop=True)
    # store again as netcdf or do what every you want with the masked array
    masked_netcdf_file.to_netcdf(OutImage)

But it is returning NaN or 0 for all values in all bands.


texts:
I'm lost on how to correctly and accurately translate Lat/Lon coordinates to XY coordinates to draw them using OpenGL.

The coordinate information I have is the following: Start Lon, Start Lat, End Lon, End Lat.

Here's some coordinates:

StartLon="-115.1051997" StartLat="36.0740197" EndLon="-115.0845997" EndLat="36.0740197"
StartLon="-115.0639997" StartLat="36.0740197" EndLon="-115.0434" EndLat="36.0740197"
StartLon="-115.0228" StartLat="36.0740197" EndLon="-115.0022" EndLat="36.0740197"
StartLon="-114.9816" StartLat="36.0740197" EndLon="-114.9609997" EndLat="36.0740197"
StartLon="-114.9403997" StartLat="36.0740197" EndLon="-114.9197997" EndLat="36.0740197"
StartLon="-114.8991997" StartLat="36.0740197" EndLon="-114.8786" EndLat="36.0740197"
StartLon="-114.858" StartLat="36.0740197" EndLon="-114.8374" EndLat="36.0740197"
StartLon="-114.8168" StartLat="36.0740197" EndLon="-114.7961997" EndLat="36.0740197"
StartLon="-114.7755997" StartLat="36.0740197" EndLon="-114.7549997" EndLat="36.0740197"
StartLon="-114.7343997" StartLat="36.0740197" EndLon="-114.7138" EndLat="36.0740197"
StartLon="-114.6932" StartLat="36.0740197" EndLon="-114.6726" EndLat="36.0740197"
StartLon="-114.652" StartLat="36.0740197" EndLon="-114.6313997" EndLat="36.0740197"
StartLon="-114.6107997" StartLat="36.0740197" EndLon="-114.5901997" EndLat="36.0740197"

I have this conversion algorithim right now, but I'm not sure if it's correct:

    private const double EarthRadius = 6371;

    public static double GetXCoord(double lat, double lon)
    {
        return (EarthRadius * Math.Cos(ToRadians(lat)) * Math.Cos(ToRadians(lon)));
    }

    public static double GetYCoord(double lat, double lon)
    {
        return (EarthRadius * Math.Cos(ToRadians(lat)) * Math.Sin(ToRadians(lon)));
    }

    public static double ToRadians(double valueInDegrees)
    {
        return (Math.PI / 180) * valueInDegrees;
    }

Any idea on how to take the four sets of Lat/Lon coordinates to accurate convert them to XY(Z) so I can plot them using OpenGL (Tao C#)?


texts: CSVLayer in the TimeSlider using ArcGIS Javascript

texts: I am trying to display the time series data in CSV using the ArcGIS Javascript API. I am working on the sample CSV layer for the timeslider, but i cant get it to show in 1 minute interval.


texts: Which architecture to adopt when working with tile layers and Cartesian coordinates?

texts:
I'm currently working on a webmapping application dedicated to warehouse management. Where data is based on indoor geolocation and Cartesian coordinates system.

More precisely, the map background is built from a LiDAR survey. I have a dedicated backend that creates a raster file then generate tiles with the gdal2tiles-leaflet script.

My web client consume these tiles with Leaflet TileLayer.
But since my GeoJSON objects are stored with Cartesian coordinates I needed to set up a conversion mechanism based on raster-coords.

My current architecture could be sum up with this diagram:

But I don't think this implementation is either efficient or robust (here I think about the conversion work).

So I would like to know if something else different is possible.
I am wondering myself if an other solution wouldn't be to convert coordinates in WGS84 and use GeoServer to directly serve the tiles as a WMS service.


texts:
I'm currently running ArcGIS 10.4.1 and am experiencing incorrect location attributes of point features when I inspect them using the Identify tool. The Location attribute changes every time the respective point is 're-identified'. I first noticed this in an existing project with a point Shapefile I was generating using ArcPy, but the problem persists in different coordinate systems and after starting a new, blank MXD.

For example, if I download this free point Shapefile from the URL below, load it into a blank map and inspect any point using the Identify tool, then close the Identify window re-identify it, the Location value will have changed considerably (sometimes up to 1 km). This happens every time I repeat the Identify process. The location given in the lower-right corner of the map window however is correct.

Free Shapefile Download - USA Pollutant Map

Has anyone experienced this before?


texts:
I successfully installed the Opengeo plugin, but it doesn't appear in plugin list.
What should i do?
Fyi, i use QGIS 2.14 for 64 bit.


texts: How to find the buildings (polygons) a user can see from a given location (point) and orientation (angle range)?

texts:
I would like to retrieve the set of buildings I can see from a given location (point -lat,lng) and orientation (interval of angles) + certainly with a given depth (e.g. 100 meters). Ideally I would like as output something like:
from angle 1 to angle2 the user can see building 1, from angle 2 to angle3 we see building 2.

Data = Polygons representing the buildings of a city in shapefile.

input: a location and an orientation (angle range) to represent the visual perception of a person.

output:
    Version 1 - a list of {BuildingID}
    Version 2 (better)- list of {BuildingID, set of visible segments for each building (facade of buildings)}
Version 3 (ideal output) - a list of {buildingID, angle ranges}. (for exemple , from angle 1 to angle2 the user can see building 1, from angle 2 to angle3 we see building 2, etc..)

Toolbox I can use: PostGis, QGis, ruby, R

start of solution for output v1:
- creating a triangle representing the simplified visual scope of the user for a given point and orientation (internval of angle) and with a certain radius/deepth (e.g. 100 meters)
- computing intersection with buildings (e.g. ST_INTERSECTION) and visual scope. but a building can hide another one so pure intersection between visual scope and buildings might add no visible buildings. this issue need to be tackled.

update: potential solution 2
- creating a triangle representing the simplified visual scope of the user for a given point and orientation (internval of angle) and with a certain radius/deepth (e.g. 100 meters)
- creating n rays (LINE) at different angles filling the scopes.
- transforming all buildings(POLYGONS) into SEGMENTS/LINES
- for each ray finding the closest SEGMENT and the related buildingID. (ST_DISTANCE , ST_DWithin)
 at this stage so we should have a list of rays and the related building ID.
- then we could aggregate this list {ranges of angle,related building ID}.

Any idea about a more efficient way to do?


texts: Is there a way to export from a vector format to Collada .dae?

texts:
I am curious if there is a way to export from a vector format (ie: shapefile for PostGIS table) to Collada (.dae).  ogr2ogr will do to GML and KML, but not Collada.  My preference is to use open source, where at all possible.

Thanks...

EDIT QUESTION

To add a little further, I am hoping to find a way to go directly from vector to Collada.  Either with an existing tool, or building upon available libraries.


texts: Shapefile not displaying in ArcGis Android SDK 10.2.6-2

texts:
I am trying to load a shapefile (not displaying at the moment) using the following:

Hardware: Android rugged tablet running Android 4.2

SDK: ArcGis 10.2.6-2

Shapefile: http://rdw.sandag.org/file_store%5CDistrict/Tax_Rate_Area.zip

My Layout:

    <com.esri.android.map.MapView
        android:id="@+id/map"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        mapoptions.MapType="Streets"
        mapoptions.center="32.713408, -117.162454"
        mapoptions.ZoomLevel="10">
    </com.esri.android.map.MapView>

My Code:

private void test4() {
    String myExternalStorageLocation = null;
    String myFileLocationPath = null;
    try {
        // in onCreate -> mMapView = (MapView) findViewById(R.id.map);
        // in onCreate -> test4();

        // Ad .shp features layer
        myExternalStorageLocation = System.getenv("SECONDARY_STORAGE");
        myFileLocationPath = "/Maps/SanDiego/Tax_Rate_Area/Tax_Rate_Area.shp";
        mShapefileFeatureTable = new ShapefileFeatureTable(myExternalStorageLocation + myFileLocationPath);
        mFeatureLayer = new FeatureLayer(mShapefileFeatureTable);

        SimpleFillSymbol simpleFillSymbol = new SimpleFillSymbol(Color.MAGENTA);
        SimpleRenderer simpleRenderer = new SimpleRenderer(simpleFillSymbol);
        mFeatureLayer.setRenderer(simpleRenderer);

        mFeatureLayer.setSelectionColor(Color.YELLOW);

        mFeatureLayer.setMaxScale(0);
        mFeatureLayer.setMinScale(0);

        mFeatureLayer.setVisible(true);

        mMapView.addLayer(mFeatureLayer);

    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
        Toast.makeText(MainActivity.this, "File not found @: "
                + myExternalStorageLocation + myFileLocationPath, Toast.LENGTH_SHORT).show();
    }
}


texts: GeoServer REST API Issue: PUT HTTP Method

texts:
I've the function below which creates or replaces an existing layer group:

public bool AddToLayerGroup(string layerGroupName, string layerName)
        {
            try
            {
                // Retrive the layer group
                string cLayerGroup = GetLayerGroup(layerGroupName);
                // Add the new layer as a new layer node among the retrieved layer nodes
                XmlDocument newLayerGrpXml = AddLayerNodeToLayerGroupXml(layerName, cLayerGroup);
                // Convert the newly created layer group xml to string
                string newLayerGrpString = ConvertXmlToString(newLayerGrpXml);
                newLayerGrpString = newLayerGrpString.Replace("<?xml version=\"1.0\" encoding=\"utf-16\"?>", "");

                // Delete the existing layer group
                //DeleteLayerGroup(layerGroupName);

                // Now, do ur thing here
                string gUrl = GEOSERVER_HOST + "/rest/layergroups/" + layerGroupName + ".xml";
                WebRequest request = WebRequest.Create(gUrl);

                request.ContentType = "application/xml";
                request.Method = "PUT";
                request.Credentials = new NetworkCredential(GEOSERVER_USER, GEOSERVER_PASSWD);

                byte[] buffer = Encoding.GetEncoding("UTF-8").GetBytes(newLayerGrpString);
                Stream requestStream = request.GetRequestStream();
                requestStream.Write(buffer, 0, buffer.Length);
                requestStream.Close();

                WebResponse response = request.GetResponse();

                return true;
            }
            catch (Exception e)
            {
                Console.Write(e.Message);
                return false;
            }
        }

This executes successfully. Tomcat logs also indicates successful execution of the PUT method. However, I can't see the created layer group using GeoServer web UI. Is there anything else I need to do after executing the above code? Trying to create another layer group with the same name fails with the error layer group already exists; a further proof that the layer group was created. But, why can't I see it using the GeoServer web UI. Any assistance will be highly appreciated.


texts: Manage QGIS layer table content within a plugin?

texts:
I want to embed a layer table in a plugin but it's not only for viewing but also for editing.

My current code below displays the content

from PyQt4.QtCore import *
from PyQt4.QtGui import *
from qgis.core import QgsVectorLayerCache
from qgis.gui import QgsAttributeTableView, QgsAttributeTableModel

layer_a = iface.activeLayer()
cache = QgsVectorLayerCache(layer_a, 10000)
model = QgsAttributeTableModel(cache)
model.loadLayer()
new_view = QTableView()
new_view.setModel(model)

new_view.show()

When I activate editing mode for the layer, I'm able to get the caption and change content but it does not persist after a "Return" to validate.

It seems I wrongly expect the sync between my current table and the content attached to the layer. I suppose it's due to the cache.
Any idea how can I sync both QtableView (native and mine)? Inserting the view from the table could be also a solution but I'm not sure it's possible.


texts: Downloading data from Sentinel's API - LTA error

texts:
I am trying to download data and I get this error when I am using the sentinelsat Python API:

sentinelsat.sentinel.SentinelAPILTAError: HTTP status 500 Internal Server Error: Trying to download an offline product
Product 93351dbb-46fe-4faf-b35d-aa7fba801ff2 is not online. Triggering retrieval from long term archive.
Trying to download an offline product
There was an error retrieving 93351dbb-46fe-4faf-b35d-aa7fba801ff2 from the LTA

Does this mean the data will be available within 24hrs since I have triggered the retrieval or does the error mean it didn’t work?


texts:
New to python, and been looking at this for a while, trying to write a scrip to automate a process we need to carry out in QGIS a few thousand times. As part of this I need to create a feature into an existing Postgres table without geometry. The existing table has approximately 40 different columsn, however I only need to populate the 6 as shown in the code.

I have the below code which I believe is correct, however the add features command doesnt seem to work, it returns False and doesnt write anything to the datbase.

def createNewIntermentRightRecord(layer,cemetery,yearsGranted,surname,firstName,otherName,liscadNo):
    if internRightsCaps & QgsVectorDataProvider.AddFeatures:
        feat = QgsFeature(layer.pendingFields())
        feat.initAttributes(6)
        feat.setAttributes(['Cemetery',cemetery])
        feat.setAttributes(['Years Granted',yearsGranted])
        feat.setAttributes(['IR Holder - LAST NAME',surname])
        feat.setAttributes(['IR Holder - First Name',firstName])
        feat.setAttributes(['IR Holder - Other Name/s'])
        feat.setAttributes(['Liscad Polygon No',liscadNo])
        (res,outFeats) = layer.dataProvider().addFeatures( [ feat ] )
        print res
        print outFeats


texts: From GCS_WGS_1984 to ED 1950 33N: no suitable transformation in ArcGIS

texts:
I have downloaded a bathymetric dataset from this web site (http://portal.emodnet-bathymetry.eu/#) in GeoTIFF format. It uses GCS_WGS_1984 coordinate system.

I have to make the dataset match the coordinate system of a DTM I have, which uses European Datum 1950, UTM 33N. In ArcGIS (10.1), I tried the 'Project Raster' facility, but it does need me to specify a geographic transformation to be selected from a drop-down menu. There seems to be no transformation suitable from the task at hand.

How can I project the bathymetric dataset to match the DTM, given the absence (in ArcGIS 10.1 at least) of a suitable transformation?


texts: MapBox Studio - Reverse Character Strings

texts:
I am working on a project in MapBox studio where I had to flip all the labels 180° that were on lines. Since its not possible to use text-orientation for labels on lines, I flipped the font file 180 degrees.

I now need to reverse the character strings before they are rendered. Is there a way to do this in MapBox Studio using CartoCSS ?

Something like

direction:rtl;


texts:
Hello right now I have a google maps page with KML Layers from multiple online resources. However all of these layers especially those from noaa have giant watermarks that take up large portions of my small map. Is there anyway to remove these watermarks? Is there a paid KML/KMZ weather service I could use that doesn't have watermarks? The feeds I am using now are

     layers[0] = new  google.maps.KmlLayer('http://www.hpc.ncep.noaa.gov/kml/fop/fopbody.kml',
            {preserveViewport: true});

    layers[1] = new google.maps.KmlLayer('http://www.nhc.noaa.gov/gis/forecast/archive/latest_wsp34knt120hr_tenthDeg.kmz',
            {preserveViewport: true});

    layers[2] = new google.maps.KmlLayer('http://earthquake.usgs.gov/earthquakes/feed/v1.0/summary/2.5_month_depth_link.kml',
            {preserveViewport: true});

    layers[3] = new google.maps.KmlLayer('http://activefiremaps.fs.fed.us/data/kml/conus_latest_lg_incidents.kml',
            {preserveViewport: true});

    layers[4] = new google.maps.KmlLayer('http://w1.weather.gov/tcig/Tornado.kml?random=115233',
            {preserveViewport: true});


texts: How to change form content dynamically in QGIS 3.6

texts:
By using "Identify Features" QGIS shows a form for viewing and editing attributes in the canvas.

Now I want to change the visible form elements dynamically by attribute value.

An example in pseudocode:

if attribute("status") = "closed":
  remove form element (attribute("status"))

In the layer properties there is the functionality of providing python code, but I have no clue how to access specific form elements. I thought it should be something like that (without conditional statement for testing), but without success:

from qgis.PyQt.QtWidgets import QWidget

def my_form_open(dialog, layer, feature):

status = dialog.findChild(QLabel,"status")
removeChild(status)

Could someone give me a hint how to access the form elements (dialog.findChild?) and change their behavior?


texts: Hiding popup template in ArcGIS API for JavaScript

texts:
I am creating a Custom Popup template as follows:

countyPop = new PopupTemplate({
            title: "County: {NAME}",
            fieldInfos: [{
                fieldName: "POP2000",
                label: "2000 Pop",
                visible: true
            }, {
                fieldName: "POP2010",
                label: "2010 Pop",
                visible: true
            }]
        });

This popup works fine and is firing when I click the layer.  However, I have some javascript to switch out the layers and when I hide this layer and show a different shape layer the popup still hangs around.

How can I stop displaying this popup when I switch to a different layer?

I tried

countyPop.hide();

It states there is a hide method in infoWindow but that does nothing.  No error is produced and the popup is still there.


texts:
Has anyone heard or know anything about the CFAI coordinate system in Nigeria?

I have tried search engines and couldn't find anything.


texts: Show Cartodb Maps infowindow on hover programatically

texts: How do i get to show the cartodb infowindow when one hovers over a point? I see that it is possible via the gui but how can one do it via code? what method should i call on the on('featureOver') event?


texts:
The data frame "Clip to Shape" feature, to hide both symbols and labels outside of a specified shape, seems to be gone from ArcGIS Pro.

I'm able to use Masking (Feature Layer->Appearance->Drawing->Masking) to get the same results for the symbols, but the labels continue to be generated everywhere.

Is there any way that will mask labels outside of a shape without having to actually clip the data?


texts: Making River/water map with stream order in QGIS?

texts:
I'm a complete novice.
I am using QGIS but am open to trying anything else.

I am trying to make a map like the example at http://www.hydrosheds.org/.

HydroSHEDS provides void filled elevation, hydrologically conditioned elevation, drainage direction, flow accumulation, and a vector of rivers.

With this data I know I should be able to 'easily' output a map like the example.

As a complete beginner I am overwhelmed with the many different ways it seems like you can do this.

What is the most simple way to create an image like the example with this data?

Should I be using a different GIS software?

Should I be using a different data set?


texts: Implementing Map Rotation in ArcGIS for Android?

texts:
I am trying to rotate the map as the orientation of the device is changed. What I want is the map should always point towards the north regardless of the orientation of the device.

Like Suppose, If I gradually rotate my device to x degrees, The map should accordingly rotate to -x degrees keeping the map facing in the same direction as it was earlier.


texts: Euclidean distance tool in ArcGIS refuses to calculate in meters

texts:
I have a shapefile with the several roads. I am using the Euclidean distance tool in ArcGIS to  create different distance bands from the roads. However, despite being careful to ensure that all the layers are in a projected co-ordinate system (UTM in this case), the tool refuses to calculate the distances in meters.

The image below shows a screenshot of the settings used for the euclidean distance tool (the cell size is being left out, and hence getting calculated automatically):

The following screenshot shows the output, using a discrete symbology:

As you can see the distances seem to be calculated in decimal-degrees and not in meters. The roads layer cover a significantly large areas, thus a value of 0.007 is too small.

I have used the distance measure tool too:

Where am I going wrong? How can I ensure that the distances being calculated by the Euclidean distance tool are in meters (i.e. the map units)?


texts: Giving polygons classificaton code in ArcGIS Desktop?

texts:
Does anyone have a trick for assigning polygons a code based on the classification classes?

For example, if I symbolize the population of census blocks with 10 classes using Natural Breaks, I would then like to add a new field to the table where each polygon will assigned a number 1 through 10 that represents the natural break class the polygon fall in. Similar to Reclassify in Spatial Analyst but using a polygon instead of a raster.


texts: Build a QGIS plugin to convert XY coordinates to a polygon shapefile

texts:
I've been trying to create a plugin in QGIS that browse an excel sheet containing XY coordinates (points) and convert them (automatically) to a shapefile (polygon on this case). If done manually, I would add the data from the CSV file and link the points one by one to get a polygon. But am trying to automate this procedure for the users by creating this plugin.

My first question would be : is this even possible ?
If so, can someone please indicate how it could be done, expecially the python code that can be used.


texts:
i´ve developed a android app that extracts the exif-information of a photo and creates a KML-file (Placemark) - some additional information like camera-type, focal length,... are stored in the tag "ExtendedData".
When i try to import the KML-file in qgis the attribute table only shows the name and description field.

is it possible to import a the KML-file in qgis without loosing any information stored in "ExtendedData"?

The KML-File is like this:

<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2">
<Placemark>
<name>20130404_132050</name>
<ExtendedData>
<Data name="Orientierung">
<displayName>Orientierung</displayName>
<value>1</value>
</Data>
<Data name="Brennweite">
<displayName>Brennweite</displayName>
<value>279/100</value>
</Data>
</ExtendedData>
<Point>
<coordinates>15.448561,47.11721,0</coordinates>
</Point>
</Placemark>
</kml>

Attributes in Qgis:

Hope you can help me!
thanks,
michael

EDIT: ok works fine now - i did not had the newest version of QGIS (2.0.1), the KML-File gets importet now correctly with all the attributes in "ExtendedData"


texts: QGIS Shortest path (point to layer) start point expression in modeller

texts:
When in QGIS I run processing tool Shortest path (point to layer) ... I am satisfied with the result (below picture red line).
But when I try to run the same tool in QGIS modeller, the result is different (see picture green line)

How to define in QGIS modeller shortest path (point to layer) START POINT in expression from point layer (see picture)?
I have three vector layers:

Start point layer (only one point)
End point layer (many points)
Network layer
All layers are in the same coordinate system: EPSG:3301


texts: Copying schema of Postgis or Spatialite DB to blank one

texts: I want to copy a Postgis or Spatialite DB sctructure (features, tables) to a blank DB. In ArcGIS i can easily handle it by using XML Workspace Document. Fisrtly extact it from a Geodatabase and than import it to blank/empty/new whatever you say. By the way the stucture of first DB copied to second DB (without data). Features (point, line, polygon etc), tables comes with this XML document. So how can i do this for Postgis or Spatialite DBs (opensource dbs). (I dont want data just structure.)


texts: Queries returning very big datasets in PostGIS

texts:
I have a PostGIS query that will return several million rows:

SELECT
 t1.id AS id1,
 t2.id AS id2,
 ABS(t1.mean_h - t2.mean_h) AS h_diff,
 ST_Distance(t1.the_geom, t2.the_geom) AS dist
FROM tas_ponds as t1, tas_ponds as t2
WHERE
 (t1.gid > t2.gid) AND
 ST_DWithin(t1.the_geom, t2.the_geom, 17000)

When run in psql, I get an out of memory for query result error.

Googling suggests that this an error within psql rather than postgres/PostGIS.  Would amending the query into the form SELECT ... INTO x FROM ... fix the problem?  Are there any other recommended approaches for dealing with very large datasets?


texts: Broadband coverage GIF image layer needs to be selectable (ArcGIS)

texts:
I am working on a project on Arcmap where I have 80,000 co-ordinates of postcodes and a broadband coverage map. I need to know which of the co-ordinates intersect with the coverage map.

I have added the coverage map in GIF format and it is a non-selectable layer. I need this layer to be selectable so that I can use 'select by location' and figure out which co-ordinates intersect it.

My project is very similar to this.

I just need the Broadband coverage GIF layer to be selectable.

Does anyone know how to do this? or can you explain a better way to go about solving this project.


texts: How to convert gridded (gnomonically projected by distance) data to lat/long data

texts:
I have a grid of data that is in a gnomonic projection, centered on a lat/long point (WGS-84). The grid has a 1km spacing. Given this I can easily obtain the x,y coordinates/distances from centre point where the latitude and longitude is known.

What is the best way to obtain the lat/long for any arbitrary datum in this grid (ie, how can I create a grid of lat/long pairs)?


texts: Polygons drawn in editable feature service through Collector cause reverse or negative geometry

texts:
I have been experiencing a very odd situation where polygons – when drawn in an editable feature service through Collector on iPad – will draw and save, then seconds later the geometry will be reversed. Instead of drawing a polygon, I end up with a polygon of the entire world with the hole cut out of it where I’ve made my polygon! Really confusing to explain…

Here’s a screen capture of my process in Collector as a test: Here I’ve drawn my polygon but not yet submitted…

After hitting submit, I get this…

For some reason I’m getting the reverse of the geometry I’m asking for.

I’ve had this problem with some, but not all of the polygon feature services that I’ve created and published to arcgis online.

Ideas?


texts:
Is it possible to change the symbology of a WMS from external developers?

I am harvesting WMS and the symbology is very messy and unclear when some are viewed together.


texts: Proj4 Task not working - Northing Easting to Lat Lng

texts:
I usually post in StackOverFlow - if this is the incorrect area to post - I apologise.

I have trying to convert a lot of northings / eastings to lat lng

I have code below working:
In ruby using this gem https://github.com/dark-panda/ffi-proj4

 class PostCodeNode < Node
  require 'ffi-proj4'
   attr_accessor :postcode, :sector, :district

  def self.from_northerns_and_eastings(northing, easting, postcode)
     srcPoint = Proj4::Point.new(easting, northing)
     srcProj = Proj4::Projection.new('+proj=tmerc +lat_0=49 +lon_0=-2 +k=0.9996012717 +x_0=400000 +y_0=-100000 +ellps=airy +datum=OSGB36 +units=m +no_defs')
     dstProj = Proj4::Projection.new('+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs')
     dstPoint = srcProj.transform(dstProj, easting, northing, 0)
     lat, lon = to_degrees(dstPoint.x), to_degrees(dstPoint.y)
     new lat, lon, postcode
  end

   def initialize(lat, lon, postcode)
     @postcode = postcode.gsub(/\s+/, '')
     @sector   = if @postcode.length == 7 then @postcode[0..4] else @postcode[0..3] end
     @district = @postcode[0..2]
     super(lat, lon)
   end
  end
end

However, the lat / lon that I am out putting end up in the middle of the sea! So I know I am doing something very wrong!

     dstPoint = srcProj.transform(dstProj, easting, northing, 0)

This line in particular is where the "magic" happens! In the test library on the git repo the test specifies some unknown numbers to me, I am not sure if I have my input data correct!
https://github.com/dark-panda/ffi-proj4/blob/master/test/transformation_tests.rb

def setup
    @proj_wgs84 = Proj4::Projection.new(["init=epsg:4326"])
    @proj_gk    = Proj4::Projection.new(["init=epsg:31467"])
    @proj_merc  = Proj4::Projection.new(["proj=merc"])
    @lon =  8.4293092923
    @lat = 48.9896114523
    @rw = 3458305
    @hw = 5428192
    @zw = -5.1790915237
  end

  def test_gk_to_wgs84
    to = @proj_gk.transform(@proj_wgs84, @rw, @hw, @zw)

    assert_in_delta @lon, to.x * Proj4::RAD_TO_DEG, TOLERANCE
    assert_in_delta @lat, to.y * Proj4::RAD_TO_DEG, TOLERANCE
    assert_in_delta 0, to.z, TOLERANCE
  end

  def test_wgs84_to_gk
    point = @proj_wgs84.transform(
      @proj_gk,
      @lon * Proj4::DEG_TO_RAD,
      @lat * Proj4::DEG_TO_RAD,
      0
    )
    assert_equal @rw, point.x.round
    assert_equal @hw, point.y.round
    assert_in_delta @zw, point.z, TOLERANCE
  end

There is no documentation with this ruby gem so I am doing a little bit of guess work, but I think I am nearly there.

Can someone see my error, so I can return the right lon/lat.

I am writing this in Jruby so any better Java Libraries could also be used :)
Thanks!


texts: Calculating SMR (standardised mortality ratio) in Field Calculator

texts:
I'd like to calculate an SMR for the number of disease cases by county. I have in my attribute table [Cases] and [Pop] and should be able to calculate the SMR with this.
In R it would be:
   caseSMR <- Case / (Pop *(sum(Case)/sum(Pop)))

I'm trying to get the field calculator to do this but the below code doesn't work (in VB Script or Python format):
caseSMR= (!Case! / (!Pop! * (sum(!Case!)/sum(!Pop!)))

I know I could pull the sums for each variable from the statistics feature but that seems inelegant and I want to know how to calculate it anyway.


texts: Replacing data in raster using condition?

texts:
I have a raster dataset in ArcGIS displaying altitude.

I want to replace all values < 8 with value 8.

Other values have to stay the same. How can I do this?

I tried raster calculator, but I don't seem to get the expression right.


texts: Getting Basic Information about ArcGIS Map Service With IGxDialog

texts:
I am having a helluva time trying to get some basic information (server URL) about an ArcGIS Map Service using the basic IGxDialog.

So far, I am able to pop open the IGxDialog, and allow the user to pick an ArcGIS Map Service by setting the appropriate filter(GxFilterMapServers).  Thats about as far as I can make it.  What should I cast pGxObj to so I can more info about the map service?

IGxDialog pGxDialog = new GxDialog();
pGxDialog.AllowMultiSelect = false;
pGxDialog.Title = "Browse For AGIS Map Service";

IGxObjectFilter pGxFCFilter = new GxFilterMapServers();
pGxDialog.ObjectFilter = pGxFCFilter;

IEnumGxObject pGxObjects = null;
if (pGxDialog.DoModalOpen(0, out pGxObjects))
{
pGxObjects.Reset();
IGxObject pGxObj = pGxObjects.Next();
while (pGxObj != null)
{
// what do I do here to get more info about the map server???
}

}


texts: Debugging Cursor object has no attribute _exit_ from ArcPy?

texts:
I am trying to replace NULL values for -999 in a table inside a gdb. I know how to replace the value for individual fields, but get an error when looping through the complete table.

import arcpy
fc ="C:\gSSURGO.gdb\chorizon_va_1"
fieldList = arcpy.ListFields(fc)

with arcpy.UpdateCursor(fc, [fieldList]) as cursor:
 fRange = range(len(fieldList))
 for row in cursor:

     for index in fRange:
         if row[index] == None:
             row[index] = -999
     cursor.updateRow(row)

And this is the error I get:

Runtime error : 'Cursor' object has no attribute '_exit_'

I found some examples using arcpy.da.UpdateCursor, but when I use that I get this error:

Runtime error <type 'exceptions.AttributeError'>: 'module' object has no attribute 'da'

I am using ArcMap 10.0.


texts: Sentinel-2 dataset on Google Earth Engine?

texts:
I'm new at Google Earth Engine and Javascript.
According to this https://explorer.earthengine.google.com/#detail/COPERNICUS%2FS2, it is possible to load/add a Sentinel-2 granule by naming the image like this:

COPERNICUS/S2/20151128T002653_20151128T102149_T56MNN

So, in my case, I've tried to load an existing Sentinel-2 granule, writing this:

var senti_img1 = ee.Image("COPERNICUS/S2/20150803T170236_20160825T061733_T15SXD");
Map.setCenter(+81.635027777777778,7.29283333333333,15);

It worked. But when I changed the dates to get another data set that's not working.
for example when i tried with followings I got an error -

new2B2: Layer error: Image.load: Image asset 'COPERNICUS/S2/20150803T170236_20180725T061733_T15SXD' not found.

var senti_img1 = ee.Image("COPERNICUS/S2/20180603T170236_20190625T061733_T15SXD");

var img1B1 = senti_img1.select('B1');
var img1B3 = senti_img1.select('B3');

var chl1 = ((senti_img1.select('B3') / (senti_img1.select('B1')))^(3.94))*(4.23);
print(chl1);


texts: Selection on PostGIS layers is... randomly working in QGIS

texts:
Context

Quick question...
Since the last minor update of QGIS 3, I cannot select features anymore on some (not all) PostGIS layers (see Fig.1).

Fig.1: On the left table, the selection is not working, but on the right it is.
Both are PostGIS layers from the same server (localhost), and both attribute tables have the option "Move Selection to Top" enabled (not shown on the image).

Using either the "DB Manager" or the "Data Source Manager | PostgreSQL"  doesn't change this behaviour.

Both are plain PostgreSQL tables, not views.

On the left layer, If I click a feature in the attribute table itself, it gets selected a few pico-seconds, then the blue background saying it's selected turns back to white. But... If I zoom to feature I have "ghostly" selected, the main screen in centered on this actual feature.

Question

Is the problem known, do I have to tweak something either inside QGIS or PostgreSQL?

Environment

Ubuntu: 18.04
QGIS: 3.12.2-București, compile against Qt 5.9.5
PostgreSQL: 10.12
PostGIS: 2.4


texts:
I have data that I would like to create a GeoTIFF file with. I have the GDAL Python package installed. I also have 3 overlapping matrices with intensity values, latitudes, and longitudes. How can I create a GeoTIFF with that?

Edit:
So this is what I am trying to do. Maybe there is a better way to do this. So I have a Geotiff file where the Geotransform is the default [0 1 0 0 0 1]. But there are tie grid points attached to the file. I preformed some segmentation on the image and I would like to replace the intensity values with the segmented image. To do this, the code I am using is :

driver = gdal.GetDriverByName("GTiff")
outdata = driver.Create(outFileName, rows, cols, 1, gdal.GDT_UInt16)

outdata.SetGeoTransform(ds.GetGeoTransform())
outdata.SetProjection(ds.GetProjection())
outdata.GetRasterBand(1).WriteArray(imgarray)
outdata.FlushCache()

outdata = None
band = None
ds = None

Where ds is the existing Geotiff file.

But the problem is this is creating a new Geotiff file where the tie grid points aren't being passed on. Therefore, when I save this new file, the geolocation information would be incorrect.


texts:
I try to convert QGIS coordinates to Google Maps coordinates.

I use this form:

geom_to_wkt( transform( $geometry, 'EPSG:25832', 'EPSG:4326' ) )

I getting the coordinate like this:

 Point (12.30982365 55.73210873)

If I copy this coordinates into Google Maps I'm ending up in the middle of the Indian Ocean, so I need to get them turned around so it simple to copy/paste to Google Maps.

Point (55.73210873 12.30982365)


texts: Looking for large GML files containing vector polygon data

texts:
I have few vector data files with 500 to 700 MB GML files. But I am looking for files larger than these preferably 1 GB, 2 GB. It would be helpful if somebody can provide some pointers regarding the place to find such files.

Note: I need to test polygon overlay over large data sets, so the two layers that I need should be intersecting.


texts: How to georeference downloaded map using ArcGIS for Desktop?

texts:
I want to georeference a downloaded map.

In the downloaded map there is no graticule but I know the projection which was used to make this map.

I also know the the location (x, y coordinates) of four points.

However, I cannot identify this location on the map.

Can anyone help with advice on how to register such a map?


texts: I want to make different buffers with Nodebo, tool fixed buffers. e.g. 300m 500m from layer a 200 m and 300 m from layer b. etc. When I try to set the file direction, there is only the possibility to select dbf or csv-file. Also when I use 'run as batch process'. The buffer is created but opens as a dbf-table not as a shape. The only way so far seems to be to select each layer single by singel, save buffer by buffer as temp-file and then save as shp. Is there a way I missed?


texts: Carto DB - problem with animated heat maps

texts:
I want to create a map that shows multiple points changing over time. So the animated heat map seems perfect. To explain why it isn't working I'll need to tell you a bit about the data I'm mapping.

I'm mapping the places people blog about when they blog about climate change. I used a geo-extractor to identify thousands of locations in thousands of blog posts. So for example I can tell you that Paris was mentioned so many hundred times in blogs about climate change during 2015, but hardly at all in 2013. (And all kinds of other interesting things). The time data is in years. I've got 12 years worth of data.

Now the problem. If I set the animated heat map "steps" number to 16 then some years fall entirely within one "step" while other years are spread over two. This means that when the map is animated it doesn't really show you the year to year progression. What I need is for each year to be one step in the animation. And to make sure all my 2014 data points light up only in 2014 and all my 2015 data points like up only in 2015.

Having played around with the various options I can't work out how to do this. But it seems like something well within the capabilities of the Torque heat map. Can anyone tell me how to do this?


texts: Refreshing modified CSV layer without having to reopen file using PyQGIS?

texts:
With an CSV layer Qgis workspace [loaded as a delimited text layer], an external algorithm is ran; outputting (writing) new values to certain rows in the layers source CSV file.

The writing works properly (CSV can be opened in text editor immediately after ext. process to show the correct values in question), yet a problem arises in the Qgis updates.  The changed values; when viewed in the attribute table depict a 'NULL' value.

Although removing and reloading the layer properly updates the attribute table, I would like to avoid such; as important temp. display-label data / settings needs to be retained.[Possibly the only option?]

I have tested the following scripts without resolve:

            csvDelimTextLayer.reload()
            csvDelimTextLayer.updateFields()
            iface.legendInterface().refreshLayerSymbology(csvDelimTextLayer)
            iface.mapCanvas().refresh()

Spending some more time revealed the following work-flow:

    -The algorithm which updates the CSV is activated

    -The updates only show a 'NULL' value in the attribute table

    -Immediately after confirming 'NULL's, save project and close QGIS

    -Upon reopening the QGIS and the project, the proper data is displayed.  Additionally (and perhaps most importantly) now every time the algorithm is ran - the reflected changes (and values) are properly viewable in the attribute table without having to resave and restart QGis.

Does this indicate an error or missing step in my initial method of allocating data in PyQgis when writing and loading the CSV; which upon saving and restarting QGis is fulfilled?


texts: How to determine when mapview zoom level has changed using Mapbox-iOS-SDK?

texts:
I am using Mapbox-iOS-SDK 2.1.2 and I need to know when the user changes zoom level on the map view.  I know how to get the current zoom level, but I don't see any delegate methods for determining when the zoom level actually changed.

My reason is I am trying to mimic the scale dependencies functionality found in ESRI, and I only want to display annotations for records in the local data store when the zoom level is 15+.

Does anyone know if Mapbox supports notification when the zoom level has changed?

Or, does Mapbox support scale dependencies?  If it does and I'm missing it, please let me know as that would save me from rolling my own version.


texts:
Can someone look at this script and see what the problem is?  It used to work with arcgis 10.3 but now I can't get it to work with 10.4 on a different computer.

import arcpy
mxd = arcpy.mapping.MapDocument(r"C:\GIS\Data and Maps\2014MDCExport_CountyWide_localData.mxd")
df = arcpy.mapping.ListDataFrames(mxd, "Layers")[0]
lyr = arcpy.mapping.ListLayers(mxd, "Grid")[0]  ##shapefile layer name called grid
rows = arcpy.SearchCursor(lyr)
x=1
for row in rows:
    df.extent = row.Shape.extent
    arcpy.mapping.ExportToJPEG(mxd, r"C:\GIS\OC Sheriffs\Image\L2\ " + str(row.getValue("PageName")) + ".jpg", df, df_export_width = 1200, df_export_height = 1200, resolution = 96, world_file=True, jpeg_quality = 100)
    print x
    x+=1
del mxd

Error:

Runtime error
Traceback (most recent call last):
  File "<string>", line 9, in <module>
  File "c:\program files (x86)\arcgis\desktop10.4\arcpy\arcpy\utils.py", line 182, in fn_
    return fn(*args, **kw)
  File "c:\program files (x86)\arcgis\desktop10.4\arcpy\arcpy\mapping.py", line 1026, in ExportToJPEG
    layout.exportToJPEG(*args)
AttributeError: DataFrameObject: Error in executing ExportToJPEG


texts: Does most topographic data come with Z Coordinates, and if so how do you put them in a QGIS map?

texts:
I am trying to create a map of the rivers in a large catchment. When I try to 'fill the sink', mine makes it as if the surface is flat. My rivers are just squiggly lines.
It doesn’t look like it has understood the Z-values of the DEM correctly. It’s basically assigning everything as a low elevation and giving you a nonsensical catchment.
How can I get my Z coordinates?
I am following this video...https://www.youtube.com/watch?v=2Ub0c7Ss-T4


texts: Writing Python Def Query for multiple layers

texts:
I have Three layers in a .mxd, all three layers have a common value I can use, but a different Label in each Layer.
As an example, the Value I want to use is "100"

In Layer A, the Value is in [Name]
In Layer B, the Value is in [Series]
In Layer C, the Value is in [SeriesName]

The Def Query for Layer A is "Name = '100'"
The Def Query for Layer B is "Series = '100'"
The Def Query for Layer C is "SeriesName LIKE '100-%'"

What I am looking for is a python script that will allow me to enter in the number,
and apply that number to all three Def Queries.


texts: Copying features from one attribute table to another using QGIS

texts:
I am struggling with copying the data from one attribute data table to another.
I have a few columns in my data attribute table, which I want to update. I can do it one by one, but its a long process, as I have about 150 records.

I decided, than it will be quicker if I do it in Excel instead, then import them into QGIS and replace the data in existing attribute data table.

I decided to do it in the following steps:
 1. Export attribute data table to .csv
 2. Make autofill in Excel
 3. Import the new attribute data table to the QGIS again
As an import I used option: Layer-Add Layer - Add delimited text layer.
After loading layer I have it own attribute layer, which I would like to copy to the attribute layer of my existing layer as per image below:

1 - my comma delimited layer imported
2 - my existing shapefile layer, where I would like to replace the attribute layer from this 1st one.

I found some solutions here:

Joining data from Excel to attribute table in QGIS without creating duplicates?

and here:

How to copy information from Excel into QGIS Attribute-Table?

but they don't really solve my issue.
I wish I could use the table joining option, but it looks like the differ columns are to be added instead to replace all with the same names.

Can anyone help me to autofill the attribute data table or fetch it from Excel?


texts: Cannot Entirely Remove Polygon Boundaries Using SLD in GeoServer

texts:
I am trying to create an SLD in GeoServer for a vector grid that will not show boundaries between contiguous polygons that are the same color. It seems that no matter how I style the strokes, I cannot completely remove the boundary.

The fill needs to be 0.5 opacity and I think that prevents me from going the route of styling the stroke the same color, since it appears to overlap and create a darker boundary.  Setting the stroke width and opacity to "0" still leaves artifacts on the boundary edges.  Removing styling for the stroke renders the same as if I set the stroke width or opacity to "0".

There are examples of each scenario below.  Does anyone know how I remove the artifacts between the polygons?

Stroke width=0, opacity=0

Style

<PolygonSymbolizer>
  <Fill>
    <CssParameter name="fill">#54278F</CssParameter>
    <CssParameter name="fill-opacity">0.5</CssParameter>
  </Fill>
  <Stroke>
    <CssParameter name="stroke">#54278F</CssParameter>
    <CssParameter name="stroke-width">0</CssParameter>
    <CssParameter name="stroke-opacity">0.0</CssParameter>
  </Stroke>
</PolygonSymbolizer>

Rendering

Stroke width=1, same fill color and opacity

Style

<PolygonSymbolizer>
  <Fill>
    <CssParameter name="fill">#54278F</CssParameter>
    <CssParameter name="fill-opacity">0.5</CssParameter>
  </Fill>
  <Stroke>
    <CssParameter name="stroke">#54278F</CssParameter>
    <CssParameter name="stroke-width">1</CssParameter>
    <CssParameter name="stroke-opacity">0.5</CssParameter>
  </Stroke>
</PolygonSymbolizer>

Rendering


texts:
I'm a developer but this is the first experience with python and QGIS Plugin, I want make a plug-in for Remote Sensing Index.
I have followed this basic tutorial https://www.youtube.com/watch?v=ZI3yzAVCK_0 and in this moment I have one dropdown with layer selection.
I correctly loaded the layer but I want see only the raster layer with multiple band for raster calculation, is it possible to filter it?
After at item selection from the dropdown list, load the band in other dropdown list for right association (green, blue, red, RedEdge ,Near IR).
Is it possible to make? What is the class prop to read?
This is almost the UI


texts: Search possibility to create markers with Leaflet, with name and description

texts:
I am looking for a possibility to create markers on a map with Leaflet. These markers will have a name and a possible description. I have seen on the website of the University of Ben-Gurion, a development that partially corresponds to my research : http://132.72.155.230:3838/js/examples/example-13-04.html
This development seems to be an extract of this page where the data is stored in a SQL database : http://132.72.155.230:3838/js/examples/example-13-05.html


texts: Weighting Point Data whilst performing a Near analysis

texts: I am struggling to work out how I can assign weights to my points (airports), So far I have carried out a Near fuction so that all of my raster (output areas ) are assigned a point with its distance being recorded. How do I now weight the different points, due to other airports being larger than others? Any Ideas?


texts: Getting Output names of Processing algorithms via PyQGIS

texts:
Calling the results of Processing algorithms in order to plot them to the screen differs depending on the provider used.

An example with QGIS provider:

tmpggis = processing.runalg("qgis:reprojectlayer",vektor,"EPSG:4326",None)
out = tmpggis["OUTPUT"]
qgisLyr = QgsRasterLayer(out, "Orfeo")
QgsMapLayerRegistry.instance().addMapLayer(qgisLyr)

So, for QGIS it is: ["OUTPUT"]    - capital letters

For GRASS it is: ["output"]   - lower case letters

What is the Output name for other providers such as Orfeo Toolbox, SAGA, etc.?


texts:
I use QGIS to illustrate the results from my Matlab simulation. Matlab produces a CSV file which is connected to a shapefile within QGIS.

At the moment I have to close and reopen QGIS to show the new results from the Matlab simulation.

Is it possible to reload the attribute-table of the CSV file without closing and reopen QGIS?


texts:
I am working to link spatial data in ArcGIS 10.3.1 (parcels with many attributes) to an Access database of customers.

Initially all I need is to identify which parcels are in my database and append the landowner names to the attribute table.

I think I can accomplish this a single time with a join.

However, I am constantly adding new customers to Access.

My desired end result is to be able to sort the parcels that are customers at any given time without having to re-join the tables.

So my larger question is:

Can (and should) I keep that link live so that it updates my parcel attributes when I have a new customer?

I would only be editing one way - data entered in Access and sent to Arc.  I have no need to use the spatial data in Access.

Is there a good solution for this?


texts:
I made a plugin to quickly analyse dxf files for work. It works fine on most .dxf files, but for some reason it does not work on all. The ones that do not work properly are imported as an "image" of some sorts. They do contain attribute values but do not poses any lines.

However, when I import those files with the "add vector layer" tool the lines do show up! I did discover that the .dxf files that do not work also contain point data, while the files that do work only contain line data.

I use the following code to import .dxf files. I am only interested in the line data of the .dxf files. Is it possible that there is something wrong with the code?

dxf_path = self.dlg.lineEdit_dxf.text()
dxf_info = "|layername = entities|geometryType=LineString"
dxf_output_filename = os.path.splitext(os.path.basename(dxf_path))[0]
dxf_vl = QgsVectorLayer(dxf_path + dxf_info, dxf_output_filename + ".dxf", 'ogr')
if dxf_vl.isValid() == True:
        QgsMapLayerRegistry.instance().addMapLayer(dxf_vl)


texts: Where can I lookup the units associated with an EPSG code?

texts:
I'm trying to find a source of information with the default units (meters, ft, ftUS) associated with an EPSG code. I'm currently using spatialreference.org and fetching URLs like this:

http://spatialreference.org/ref/epsg/2284/proj4/

And then looking at the to_meter field to see if it's ft ftUs or m.

The problem is that the site seems to be incomplete for example they don't have EPSG:6505

http://spatialreference.org/ref/epsg/6505/proj4/


texts: Problem with custom projection in OpenLayers

texts:
I'm using OpenLayers 2 with Proj4JS 1.10. When trying to change the map's projection using

Proj4js.defs['STEREOGRAPHIC:180,90'] = "+proj=stere +lat_0=90 +lon_0=180 +a=3396190.0 +b=3396190.0 +over=F +geoc=T";
map.baseLayer.projection.proj = new Proj4js.Proj('STEREOGRAPHIC:180,90');

and then zooming in to refresh the map, I get a JavaScript error tracing back to the Graticule control: Uncaught TypeError: Cannot read property 'x' of null.

Is there an issue with my proj4 string or could this be a bug with OpenLayers or Proj4JS?


texts: Merging/Dissolving polygons with same attributes

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I'm interested in the areas of my investigation area where the slope is smaller than 25%. For this, I used elevation raster data SRTM 90m Digital Elevation Database v4.1 from CGIAR-CSI (http://srtm.csi.cgiar.org/srtmdata/) in CRS 4326.
I used the following data processing steps:

I clipped the data to my investigation area
I used Raster > Analysis > Slope with a ratio of vertical units to horizontal units of 111120 to calculate the slope in percent
I used Raster > Conversion > Polygonize to receive polygons
I checked the calculated slopes and they are in reasonable magnitude and seem plausible
I added a new field with the Field calculator with:
 "Slope" <= 25

I deleted the field Slope

Thus, I have a lot of small polygons, which have the attributes 1 or 0 depending on if the slope is smaller than 25%. Now I would like to combine the polygons together, as I am merging several vector layers later on. I tried Vector > Geoprocessing Tools > Dissolve. However, a lot of geometries seem to be invalid and are skipped.

This approach gives me this result:

Is there another way of merging the polygons together without losing some areas?


texts: Joining csv file to vector layer in Processing modeler?

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I am trying to join a simple CSV file of values to a vector layer within Processing modeller.

The match would be on an ID held by both files. The CSV file has no geometry.

I can do this easily in QGIS, but want to automate the process in Processing modeller. Is this possible?

I have looked through (and tried) a number of the functions but have not found anything that works.

I am using QGIS 2.0.1


texts:
Is there a method in ArcPy that will rename the MXD you currently have open? I don't want to use mxd.saveACopy("newFileName") as it will just save a COPY with a new name, not rename the current MXD.

Basically I want a method that will replicate the File > Save As > "newFileName.mxd" process.

os.rename() wont work, as the document is currently open.

Is this just a simple case of can't be done with ArcPy, use ArcObjects?


texts: Connect QGIS to Esri geodatabase hosted on RDBMS (PostgreSQL)

texts: I have an ArcGIS 10.5.1 enterprise geodatabase hosted on PostgreSQL 9.4 (non-PostGIS enabled, but with SDE.ST_Geometry support). I'd like to add some feature classes as layers in QGIS. How can I do this?


texts: Creating point C from point A in direction of point B using QGIS?

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I have pairs of coordinates which signify the start and end of a transect line. I am trying to adjust the end point such that it is x meters from the starting point.

What I have:

Coordinates of Points A and B.

What I want to accomplish:

Create a point C such that it is x meters from point A in the direction of B; or
Move point B such that it is x meters from point A in the same direction.

Of course I could do this manually since I have just more than a dozen points, but I am trying to be a bit more accurate.


texts: QGIS. get intersect line segments from polygons

texts:
I have 2 types of Polygons. one big Polygon (P1) and multiple smaller polygons (P2) all located inside P1.

Is there a way to get the line segments that intersect/touch?.

Running "Geoprocessing Intersect" gives me the polygons. I only need the actual lines segments that touch not the whole polygons.

I'm attaching an example image, I need to get the red line. Is it possible to do this automatically?


texts: Retrieving lines radiating from point with v.select in GRASS GIS 7.6

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I am attempting to select lines that radiate from a point using v.select in GRASS GIS 7.6 (also tested with 7.4.4) in Windows 10.

I start out with 48 lines radiating from a point every 7.5 degrees. These are then clipped by the vector representing the sea (as seen in figure 1), and I subsequently want to retrieve the lines that are still
touching the point.

However, running the following command only selects 11 of these lines (figure 2).

v.select ainput=temp_radials_clipped atype=line binput=random_point btype=point output=lines_vselect operator=overlap

All the lines share the exact same origin point at the coordinates of random_point. I have tried all the different operators for v.select, and only 'overlap' returns any lines at all
(this also includes 'intersects' which is to be the GEOS equivalent of 'overlap'). I have trouble understanding why v.select with 'overlap' should return any lines at all if it is not returning all of the lines touching the point.

I am also open to alternatives to v.select to achieve this.


texts: Is there a limitation on the numbers of layers that can be displayed in QGIS?

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I have been looking for an answer to this question for the last several weeks, so hope that someone here has encountered the same issue and has a viable solution to my problem.  I am currently using the following configuration:

•   Windows 7 Pro

•   QGIS 2.2 (also tested 2.4 with same issue on a separate system)

The issue I am seeing is that that once I reach 254 or 256 layers added to a project, as soon as I add any additional layers, all layers disappear from my map and I am unable to see any of my data.  I work with large amounts of data.  Is this a limitation in QGIS or is it a setting somewhere?  I have also tested MapInfo, which I am thinking of buying if QGIS is unable to handle the load; MapInfo does not have this limitation.

Any ideas?  I can provide more information if necessary.

Thanks


texts: ArcGIS Online scrape info from a website dynamically

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It seems like this is do-able but I don't know what tools would work best. I have a feature service of Parcel data that includes a parcel PIN. Each parcel has a corresponding web page that can be accessed by appending the PIN to a static url. Once you're on that page there is a plethora of additional information in tables. I would like to be able to extract this info and append it to my feature service.

For example, I would like each parcel to include the Owner name in the Pop-up. Owner name is listed on the webpage, so I should be able to scrape it somehow. Ideally a solution would do this using Arcade in the Pop-up so it's always correct, but I would be fine with running a tool ever so often.

Is there a way to do this in ArcGIS Online, or with some other open source tool that is more simple than, "build a web scraper?"


texts: How to clip raster by multiple polygons in multi rasters?

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Using QGIS, I want to clip a raster by multiple polygons contained in a single shapefile. I read that gdalwarp can clip my raster by multiple polygons BUT the output is a single merged clipped raster.

I want to have one clipped raster per polygon. If I have 20 polygons, I want to have 20 clipped rasters at the end :-)

I can't find any option of gdalwarp that allows me to do this. Do you have any idea ?


texts: Trying to project a shapefile to line up with another shapefile?

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I have two polygon shapefiles representing district boundaries: Districts1 and Districts2.

They are supposed to represent the same geographical area and same district boundaries, but I realized that Districts2 seems to be regularly offset by ~245 feet, whereas Districts1 lines up properly with the Basemap and appears to be correct.
The image below illustrates an example of this, where the red shapefile is Districts2, and black is Districts1:

I looked at the projections for the files and for whatever reason, they're different.

This is the information for Districts1:

And this is the information for Districts2:

So the projection information for Districts2 looks fishy to me, but I'm not sure how to fix this...
I tried projecting Districts2 into the POSGAR_94 coordinate system that Districts1 uses, but it didn't make any spatial changes. I don't know if the fact that the datum is unknown for Districts2 has anything to do with this. I also tried changing the data frame's coordinate system but that didn't do anything to better line up Districts2 either.

Evidently I'm a bit lost; I've been trying to read up on projections and datums but I can't seem to figure this out.

Edit: Michael Stimson below pointed me to the spatial adjustment toolbar, which did indeed work. However I am still interested in any insight regarding the projection discrepancy and why the shapefiles look the way they do, and specifically how I might interpret the information for Districts2 (there being no datum, the coordinate system just being "Transverse Mercator", etc.)


texts:
I've wrote a plugin and when I was tested it I found a plugin's case of use that it has to handle with null values. I've had some research and doesnt found much about it in PyQGIS3 documentation, but I read about NULL from qgis.core and write the code below:

from qgis.core import QgsProject, NULL

layer = QgsProject.instance().mapLayersByName('My_Layer_Name')[0]
selection = layer.selectedFeatures()
n_sel = layer.selectedFeatureCount()

if n_sel > 0:
    layer.startEditing()
    for feature in selection:
        pos = feature['offset_quad']
        if pos == NULL:
            pos = 0
        else:
            pos = int(feature['offset_quad'])
    # do some stuf here

I'd like to know if there is a better "pythonic" way to do this test for null values.


texts: How to make MapServer only accessible via MapCache?

texts: I installed MapServer and MapCache on Ubuntu (see here). Now I would like to prevent the direct access to MapServer - requests should only be allowed via MapCache. I thought I could achieve this by accessing MapServer via localhost (in mapcache.xml / source) and allowing MapServer to only serve to localhost. The former works fine, but how to allow MapServer only serving to localhost?


texts: Force L.control.layers to stay permanently collapsed

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I am building a map with Leaflet 1.3.1 containing two layers controls (Control1 and Control2). For some reasons, I want one of them (Control2) to be displayed on the map, and I need it to stay permanently collapsed (in fact I only want the control background picture to be displayed) :
var Control1 = L.control.layers(baseMaps, overlayMaps, {collapsed: false}).addTo(map);
var Control2 = L.control.layers(baseMaps, overlayMaps, {collapsed: true}).addTo(map);

I tried to disable mouse hover events in my CSS :
.leaflet-control-layers{
pointer-events: none;}

Which does exactly what I want, but for both controls.
I only need to apply that style to my Control2 variable, how can I proceed ?
I don't know how to edit L.control.layers class.


texts:
Imagine you have a GPS trace that you want to make anonymous, in the legal sense. How would you do this? Is snapping to the nearest x distance and stripping out the time enough? Are there internationally agreed standards on this? Has anyone already written an algorithm to do this? If not I plan to make a function in my evolving stplanr package to do this.

Reproducible example (using awesome rotation function from @geospacedman) from my own 'Identifiable' data:

library(rgdal)
library(tmap)
downloader::download("https://www.openstreetmap.org/trace/1619756/data", "test.gpx")

r <-readOGR(dsn = "test.gpx", layer = "tracks")
r <- spTransform(r, CRS("+init=epsg:27700"))
rproj <- rotateProj(rs, 90) # rotate projection for plotting
r <- spTransform(r, rproj)
rs <- rgeos::gSimplify(r, 1000) # snap to nearest km
qtm(r) + qtm(rs, line.col = "red") + tm_layout(draw.frame = F) + tm_scale_bar()

The result is shown above. In summary: is the red route 'identifiable' and is there a better way?


texts: Change variable in which polygon colors are based (in Carto)

texts: I have crossed a polygon layer with a dataset, and I can color the polygons depending on the value of one dataset variable. Is it possible with the builder to allow the user to switch the variable in which the polygon colors are based?


texts:
To start, I found a similar question posted on stack exchange here, but I am not using the zonal statistics tool, which the answer to that question is based on.
With that out of the way, I'm attempting to write a very simple arcpy script.
The purpose of the script is to reclassify the values of an input raster, and save the output to a folder.
Currently I'm using this script in a toolbox. I am using arcpy "GetParameterAsText" to determine the input file and output folder.
I have tried using raw file paths instead of using GetParameter, but the script still fails. The file paths I use never include spaces, so I think that can be ruled out.
Here is the code:
#Import libraries
import arcpy, sys, os
arcpy.env.overwriteOutput = True
from arcpy import env
from arcpy.sa import *

#Have tried GetParameter as well as raw file paths/names
input = arcpy.GetParameterAsText(0)
saveFolder = arcpy.GetParameterAsText (1)

#Have confirmed following line works using the python window within arcmap
planAreas = Reclassify(input, "VALUE", RemapRange([[100, 169, 0], [170, 179, 1]]))

planAreas.save(saveFolder) #Crashes here

If I run just the "Reclassify" function in the ArcMap python window, it successfully saves an output as a feature class in Default.gdb.
Running the very same code, but in an python script using the save function, crashes with the dreaded error 999998.
I am using Arc version 10.6.1


texts: "Points in Polygon" command (vector-analysis tools) doesn't appear in QGIS 2.16

texts: I can't find the "Points in Polygon" command under the vector-analysis tools. It is missing from the pull down menu.  Any ideas why?  I just loaded QGIS for the first time on my new PC.


texts: Export layered SVGs from GPlates to GIMP

texts:
I'm using both GPlates and GIMP for the project I'm working on, and I need to export a layered image from GPlates to the GIMP.

Is it possible to export a layered SVG (or any format) from GPlates to GIMP that can still be read by the latter? If so, how?