texts:
I have a problem: I'm trying to georeference a satellite image (ASTER, ERDAS Imagine file *.img) in QGIS. I have georeferenced with QGIS before and never had any problems. The file is georeferenced already in UTM 17N WGS 84 but very, very badly, so I need to re-do it.

I have opened the file in QGIS and set the project coordinate system to UTM 17 N, then I have added a basemap with OpenLayers and used the basemap (Bing Maps) to generate GCPs using the Georeferencer tool. I set the output coordinate system to UTM 17 N, too.

Everything looks good, but when I finish the georeferencing, the file ends up in the wrong place (or in no place at all rather, the basemap disappears when I zoom to the layer). Sometimes it doesn't even display. I have tried different coordinate systems, re-sampling methods, also saved the file as .tiff - no changes. I have tried it with other raster files, they always worked well. Does anybody have any idea what I'm doing wrong?

(Just in case: I have tried with ArcGIS, that doesn't work because I don't have a BingMap access key and the basemap I can access has a worse resolution than my ASTER image. Same problem in ERDAS, theoretically I could use Google Earth for georeferencing there but I'm using a computer at my university and the Google Earth tool isn't working).

I'd be very, very glad if anybody has a suggestion, this is for my bachelor thesis and quite important, and I've spent two days already trying... :)


texts: Using SRTM DEM with 16 bit signed pixel type changes to 32 bit float when creating slope/aspect/curvature?

texts:
I have mosaiced 8 SRTM DEM tiles in order to get one raster layer of elevation. When I use "Mosaic to New Raster" tool I set as a pixel type format "16 bit signed" because this is the format that SRTM uses. When I construct slope/aspect/curvature the raster changes pixel type and from 16 bit signed becomes 32 bit float.

Why does this happen and does it corrupt my analysis?

I use ArcGIS Desktop 10.2.


texts: Converting from polyconic projection to UTM or geographic coordinates

texts:
I have a .dat file with x,y having this projection description:

  A polyconic projection is used. The WGS84 datum system, which is
  based on the GRS80 ellipsoid, is used as the geodetic reference
  system. The origin of the projection is 36 degrees north latitude and
  136 degrees east longitude.

An example of the data:

1249500.0      -     1278500.0
1249000.0      -     1278500.0
1248500.0      -     1278500.0

When I convert the file to .xls and plot it into ArcGIS the data locate somewhere else Japan.

How to display these data in ArcGIS with this projection? Or
how to transform this projection to UTM or to geographic coordinate sysyem?


texts: When moving a feature in QGIS, is there a way to nudge it rather than use the mouse?

texts:
I need to move a lot of features (polygons) in QGIS to fit a newly Georeferenced scanned map that is slightly asymmetrically distorted. This is fine as it is just to provide a print copy.

I end up having to do multiple moves of each polygon using the mouse until they are in the right place, because it is easy to overshoot.

As in some image manipulation programs is there a way to turn on using the arrow keys, perhaps with Shift or Ctrl, to nudge a feature in a particular direction?

The arrow keys pan the map even when the Move Feature(s) is activated, or the feature selected, with or without, Shift or Ctrl.


texts: drawing tools for (lines,polygon and points) in QGIS 2.4.0

texts: I want to draw lines, polygon and points without necessarily creating a shapefile in QGIS. Please help


texts: Why having problem with GDALRasterize() in C?

texts:
I am trying to make raster file from a shapefile. I am trying to use GDALRasterize() function for it. But it is not recognizing GDALRasterize function ('GDALRasterize' was not declared in this scope). But I have included GDAL.h, cpl_port.h.

#include <stdio.h>
#include <stdlib.h>
#include <gdal.h>
#include <cpl_conv.h>
#include <cpl_port.h>

//main function
int main()
{
char path1[200],path2[200],filename1[]="/inRasters/line.tif",filename2[]="/in_shapes/line.shp";
GDALDatasetH lineDS,lineDS_shp;

GDALAllRegister();

getcwd(path1, sizeof(path1));
strcpy(path2,path1);
strcat(path1,filename1);
strcat(path2,filename2);

lineDS_shp = GDALOpenEx(path2, GDAL_OF_VECTOR, NULL, NULL, NULL );
lineDS = GDALRasterize(path1,NULL,lineDS_shp,NULL,NULL);

GDALClose(lineDS_shp);
GDALClose(lineDS);
return 0;
}


texts: Dealing with NODATA_VALUE of ascii grid in qgis2threejs plugin?

texts:
For a project I have modelled the upper and lower boundaries of geologic layers in the subsurface. The resulting rasters are stored as ASCII files with a NODATA_VALUE of -999. However, when I visualize the ASCII file, using the qgis2threejs plugin, the pixels or cells that have nodata are shown as 0 (see images below).

Is it possible for the qgis2threejs plugin to recognize cells with a nodata value and visualize only the part of the raster with valid values?


texts: How to reproject shapefile using ogr2ogr

texts:
I have shapefile in EPSG:2834 and I want to reproject it into EPSG:4326. I am trying to use ogr2ogr in Windows; however, I get this failure output:

C:\Users\Nik\Desktop\Logan_Lines>ogr2ogr -t_srs epsg:4326 spans_4326 spans
FAILURE:
Unable to open datasource `spans' with the following drivers.
  -> ESRI Shapefile
  -> MapInfo File
  -> UK .NTF
  -> SDTS
  -> TIGER
  -> S57
  -> DGN
  -> VRT
  -> REC
  -> Memory
  -> BNA
  -> CSV
  -> NAS
  -> GML
  -> GPX
  -> KML
  -> GeoJSON
  -> Interlis 1
  -> Interlis 2
  -> GMT
  -> SQLite
  -> ODBC
  -> PGeo
  -> OGDI
  -> PostgreSQL
  -> MySQL
  -> XPlane
  -> AVCBin
  -> AVCE00
  -> DXF
  -> Geoconcept
  -> GeoRSS
  -> GPSTrackMaker
  -> VFK

C:\Users\Nik\Desktop\Logan_Lines>

I am hoping someone can tell me what I am doing wrong; I have little experience with this tool.


texts: import shapefile to postgis with customized projection using ogr2ogr2

texts:
I have a shapefile with a customized projection

PROJCS["NAD83_Lambert_Conformal_Conic_CN",GEOGCS["GCS_North_American_1983",DATUM["North_American_Datum_1983",SPHEROID["Geodetic_Reference_System_of_1980",6378137,298.2572221008916]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]],PROJECTION["Lambert_Conformal_Conic_2SP"],PARAMETER["standard_parallel_1",33],PARAMETER["standard_parallel_2",60],PARAMETER["latitude_of_origin",43],PARAMETER["central_meridian",-96],PARAMETER["false_easting",0],PARAMETER["false_northing",0],UNIT["Meter",1]]

I have read the projection string and define a customized projection system

INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text,srtext) values ( 94326, 'epsg', 94326, '+proj=lcc +lat_1=33 +lat_2=60 +lat_0=43 +lon_0=-96 +x_0=0 +y_0=0 +datum=NAD83 +units=m +no_defs', 'PROJCS["NAD83_Lambert_Conformal_Conic_CN",GEOGCS["GCS_North_American_1983",DATUM["North_American_Datum_1983",SPHEROID["Geodetic_Reference_System_of_1980",6378137,298.2572221008916]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]],PROJECTION["Lambert_Conformal_Conic_2SP"],PARAMETER["standard_parallel_1",33],PARAMETER["standard_parallel_2",60],PARAMETER["latitude_of_origin",43],PARAMETER["central_meridian",-96],PARAMETER["false_easting",0],PARAMETER["false_northing",0],UNIT["Meter",1]]');

However, ogr2ogr2 cannot interpret my newly define projection

ogr2ogr -f "PostgreSQL" PG:"host=1.1.1.1 user=geotest dbname=dbname password=password" LRS_DATUM.shp -a_srs "EPSG:94326"

returns

ERROR 6: EPSG PCS/GCS code 94326 not found in EPSG support files.  Is this a val
id EPSG coordinate system?

How can I get around this?


texts: QGIS Seem To Bypass PostgreSQL/PostGIS User Privileges/Permissions

texts:
I created a "Read-only" User in PostgreSQL via a Role with "SELECT" ONLY privilege on all tables in a schema as shown below:

GRANT SELECT ON ALL TABLES IN SCHEMA [schema_name] TO [role_name]
GRANT [role_name] TO [user_name]

Next, I test this by trying to UPDATE a column in a table (same schema as above) with pgAdmin/psql and this works fine by giving a response that the user has no permission - 'ERROR: permission denied for relation <table_name>.'

Next, I connect with the same user in QGIS and add a layer from the same table (same schema as above). I open the attribute table for the layer, turn on editing mode (by clicking on the pencil-like icon), and edit the same field/column above. To my surprise, the edit was saved successfully without any permission error prompt.

Next, I check the value of the field/column (same table/schema as above) in pgAdmin/psql and it is having the new (edited) value from QGIS. This is rather strange as it seems QGIS is bypassing the permissions set for the same user in the PostgreSQL/PostGIS database.

I will be glad if someone can help me unravel this mystery.


texts:
When we search for a zip code in Google Maps we get the area highlighted in the map with a dotted border.

How is this calculated?

How do they know how to draw the polygon?

I'm looking at implementing something equivalent, an overlay on each zip code of the visible area of the map.


texts: Heading rate/bearing from GPS points in BigQuery

texts:
I want to calculate heading rate / bearing from GPS points in Big Query. I've check all of the geography functions in BQ but found nothing helpful. Has anyone done it in BQ?
My data consist of GpsLongitude, GpsLatitude and DateTime. I want to calculate change in heading rate / angle / bearing between each current and previous GPS point (each GPS point is 10 seconds apart from previous GPS point).


texts: Which part(s) of the ArcMap user interface uses the Rogue Wave Objective Grid(OG1200ASU.DLL)?

texts:
I'm trying to troubleshoot ArcMap 10 crashing when I reconcile a version and I think it is OG1200ASU.DLL causing the problem.  I'm guessing it's the attribute table or the attribute inspector.

GetProcAddress(0x773D0000 [c:\windows\winsxs\x86_microsoft.windows.common-controls_6595b64144ccf1df_6.0.2600.6028_x-ww_61e65202\COMCTL32.DLL], "InitCommonControlsEx") called from "c:\windows\winsxs\x86_microsoft.vc90.mfc_1fc8b3b9a1e18e3b_9.0.30729.4974_x-ww_a96f9c14\MFC90U.DLL" at address 0x78A43931 and returned 0x773D4088.
LoadLibraryW("DbgHelp.dll") called from "c:\program files\arcgis\desktop10.0\bin\AFCORE.DLL" at address 0x007144A4.
Loaded "c:\program files\arcgis\desktop10.0\bin\DBGHELP.DLL" at address 0x28380000.  Successfully hooked module.
DllMain(0x28380000, DLL_PROCESS_ATTACH, 0x00000000) in "c:\program files\arcgis\desktop10.0\bin\DBGHELP.DLL" called.
DllMain(0x28380000, DLL_PROCESS_ATTACH, 0x00000000) in "c:\program files\arcgis\desktop10.0\bin\DBGHELP.DLL" returned 1 (0x1).
LoadLibraryW("DbgHelp.dll") returned 0x28380000.
GetProcAddress(0x28380000 [c:\program files\arcgis\desktop10.0\bin\DBGHELP.DLL], "MiniDumpWriteDump") called from "c:\program files\arcgis\desktop10.0\bin\AFCORE.DLL" at address 0x007144B4 and returned 0x283DD4F0.
Second chance exception 0xC0000005 (Access Violation) occurred in "c:\program files\arcgis\desktop10.0\bin\OG1200ASU.DLL" at address 0x064A310B.
Exited "c:\program files\arcgis\desktop10.0\bin\ARCMAP.EXE" (process 0x1298) with code -1073741819 (0xC0000005).

Update:
I've narrowed my issue to the attribute table.  When I start up ArcMap with the attribute table window docked, edit, then reconcile...ArcMap crashes.

If I start up ArcMap, close the attribute table window (or auto-hide), then edit, then reconcile...success!

If I start up ArcMap, close the attribute table window (or auto-hide), then open the attribute table window again, then dock (which effectively puts the attribute table window in same condition as it was on startup) , then edit, then reconcile...success!

http://dl.dropbox.com/u/1156285/ArcMap_Reconcile_CrashReproduce.avi


texts:
I am currently using Mapbox in order to complete one of the first examples but something strange is happening. My cluster tiles are not being displayed for some reason. I don't receive any kind of error message and my map is loading perfectly fine. I am currently using data from usgs.gov about 4.5 hour earthquake update.

Here is my how I loaded all my src and style files.

        <script src='https://api.tiles.mapbox.com/mapbox-gl-js/v0.28.0/mapbox-gl.js'></script>
        <script src="http://cdn.leafletjs.com/leaflet/v0.7.7/leaflet.js"></script>
        <script src = "leaflet-providers.js"> </script>
        <script src="http://code.jquery.com/jquery-1.11.3.min.js"></script>
        <link href='https://api.tiles.mapbox.com/mapbox-gl-js/v0.28.0/mapbox-gl.css' rel='stylesheet' />

I was not using <script src = "leaflet-providers.js"> </script> initially but decided to add it to see if it will fix the issue. Well, it didn't.

JS Code as copied from the Tutorial:

mapboxgl.accessToken = 'XXXXXXXX';
var map = new mapboxgl.Map({
    container: 'map',
    style: 'mapbox://styles/mapbox/dark-v9',
    center: [-36.77344,  41.138952],
    zoom: 2
});

var nav = new mapboxgl.NavigationControl();
    map.addControl(nav, 'top-right');

map.on('load', function() {

    // Add a new source from our GeoJSON data and set the
    // 'cluster' option to true.
    map.addSource("earthquakes", {
        type: "geojson",
        // Point to GeoJSON data. This example visualizes all M1.0+ earthquakes
        // from 12/22/15 to 1/21/16 as logged by USGS' Earthquake hazards program.
        data: "https://earthquake.usgs.gov/earthquakes/feed/v1.0/summary/4.5_hour.geojson",
        cluster: true,
        clusterMaxZoom: 14, // Max zoom to cluster points on
        clusterRadius: 50 // Radius of each cluster when clustering points (defaults to 50)
    });

    // Use the earthquakes source to create five layers:
    // One for unclustered points, three for each cluster category,
    // and one for cluster labels.
    map.addLayer({
        "id": "unclustered-points",
        "type": "symbol",
        "source": "earthquakes",
        "filter": ["!has", "point_count"],
        "layout": {
            "icon-image": "marker-15"
        }
    });

    // Display the earthquake data in three layers, each filtered to a range of
    // count values. Each range gets a different fill color.
    var layers = [
        [150, '#f28cb1'],
        [20, '#f1f075'],
        [0, '#51bbd6']
    ];

    layers.forEach(function (layer, i) {
        map.addLayer({
            "id": "cluster-" + i,
            "type": "circle",
            "source": "earthquakes",
            "paint": {
                "circle-color": layer[1],
                "circle-radius": 18
            },
            "filter": i === 0 ?
                [">=", "point_count", layer[0]] :
                ["all",
                    [">=", "point_count", layer[0]],
                    ["<", "point_count", layers[i - 1][0]]]
        });
    });

    // Add a layer for the clusters' count labels
    map.addLayer({
        "id": "cluster-count",
        "type": "symbol",
        "source": "earthquakes",
        "layout": {
            "text-field": "{point_count}",
            "text-font": [
                "DIN Offc Pro Medium",
                "Arial Unicode MS Bold"
            ],
            "text-size": 12
        }
    });

});

I really don't know why is this happening. Can you please help me figure it out. Should I build a back end in order to constantly refresh the data?

Example I used : Example from Mapbox website.


texts: How to select features containing specific text string using an expression in QGIS

texts:
I need to style a survey parcel polygon shapefile, based on whether the polygon is a mineral claim or not. Unfortunately, the only information on whether a polygon is a mineral claim or not is contained in the "TITLE" field of the attribute table, which gives the full legal name of the surveyed parcel.
For instance, 'DISTRICT LOT 5639, BEING AWARD NO. 2 MINERAL CLAIM, KDYD'.
I need an expression that selects any feature containing the text 'MINERAL CLAIM' in the "TITLE" field.


texts:
I'm trying generate a heatmap from my PostGIS table, but my map is empty...

Here is my config file:

LAYER
  NAME feature_heatmap
  TYPE raster
  CONNECTIONTYPE kerneldensity
  CONNECTION "point_data"
  STATUS ON

  PROCESSING "RANGE_COLORSPACE=HSL"
  PROCESSING "KERNELDENSITY_RADIUS=50"
  PROCESSING "KERNELDENSITY_COMPUTE_BORDERS=ON"
  PROCESSING "KERNELDENSITY_NORMALIZATION=auto"
  OFFSITE 0 0 0

    CLASS
        STYLE
            COLORRANGE  "#0000FFFF"  "#FF0000FF"
            DATARANGE 0 255
        END
    END
 END

And my "point_data" layer:

layer
    name "point_data"
    status on
    processing "close_connection=defer"
    extent -180 -90 180 90
    projection
        "init=epsg:4326"
    end
    connectiontype postgis
    connection "MY CONNECTION STRING"
    data "geom from my_geom_table using unique id using srid=4326"
    type point
    metadata
        "ows_title" "feature_heatmap"
        "ows_abstract" "Test heatmap"
        "ows_srs" "epsg:4326"
        "ows_enable_request" "*"
        "wms_timeitem" "pass_time"
        "wms_timeextent" "2001-01-01/2018-12-31"
        "wms_timedefault" "2001-01-01"
    end
end

My result:

Only "point_data" layer:


texts: Automating creation of multiple maps with different layers on same location in QGIS?

texts:
I was wondering if it is possible in QGIS 3.2 to cycle through different layers.

For example, I have a workspace open with 3 raster layers (A, B and C). I would like to create 3 maps:

Map A with Layer A and Legend A
Map B with Layer B and Legend B
Map C with Layer C and Legend C

The only difference in all these maps is the switching of the raster layer and the legend of the layer. Everything else is the same.

I found a similar question before but it appears to be unanswered.

Creating atlas of different layers on the same place (QGIS)


texts: Combining small watershed in a better way

texts:
I used grassgis delineated watersheds in a large area. After vectorizing the watershed raster, I ended up with a lot of tiny watersheds.

"Dissolve" did help a bit, but there are about 1200 watersheds I would like to eliminate.
The "eliminate" tool in ArcGIS could do the job most of the time, while wrong combinings still occur.The following pic is not exactly the wrong combining, but looks like it.

I need to eliminate some small watersheds to have most of the watersheds around 100 sq km. And the eliminated watershed would be combined to an adjacent one which belongs to the same drainage system.

Are there any tool can combine those small watershed wiser?


texts: Code for Extraction of pixel values post Temporal Averaging

texts:
I tried to write a code for temporal averaging the pixel values of VH polarization from Sentinel 1 collection and downloading the same as a CSV. I get an error "VH value not selected in the dictionary".
Kindly help!!
The code is available at
https://code.earthengine.google.com/b3f2ab9b87794f9705dbca782d21a38f


texts: Defining a projection and CRS for shapefile with undefined projection?

texts:
I am having some shapefiles without a defined projection (.prj files)

I used shp_doctor available at https://www.gaia-gis.it/fossil/spatialite-tools/index to identify the files.
The extents provided to me by the program are as follows:

488340.166723, 552417.623699
330265.123073, 433755.593428
517634.601459, 504177.307156

I am also aware of the corresponding lat/lon which are (nearby):

22.189171,69.9567533
22.8049742,70.8217758
23.4302321,72.6454342

I have read several blogs about northing and easting but I was not able to find any specific information regarding the co-ordinates (x,y) to be (6 digits, 6 digits) (Easting, Northing). I only found information regarding (x,y) to be (6,7 digits) (Easting, Northing).


texts: Hosting GeoServer+Openlayers web mapping application on internet?

texts:
I have created a web mapping application prototype using GeoServer (running on Tomcat as the servlet), Openlayers and PostGIS. Since it was a prototype, at that time, i did not bother about the hosting aspects of it. It was working fine on my (laptop) localhost: 8080.

Now as part of my job, i am requested to develop a similar application but this time it has to go on the web, such that person x can access it via www. The agency i work for has a website running however they want it to be a separate thing of its own, hosted separately from the website.

These are my questions:

what are the steps/options to follow in order to host a web mapping application on the web such that someone outside of the agency's intranet or for e.g. in my case, someone other than the localhost can access it as well? (Considering that i have one that is functioning and accessible via localhost only, and now i want someone else to access it also on their machine).
If so, how can i implement this? In the event that the agency decides to have it as part of their website in future.

I have read through some post and responses here that is somehow related however I'm getting confused so I am hoping someone can help respond to my specific query.


texts: How to convert Whitebox .dep files for use in e-Cognition?

texts:
Could you explain me how can I convert .dep files into correct files to work in e-Cognition?

I’ve exported the file in .sdat and .sgrd form using Export Layer, but I lose a lot of resolution. Any suggestion?


texts: Preserving resolution while creating image using GDAL?

texts:
I have to save /Export raster layer to image . How this can be done using Python Script .

I can do this with GDAL script but this creates an image with low resolution

 gdal_translate -of GTiff abc.tif out.jpeg

or,

 gdal_translate -of JPEG -B 1 -B 2 -B 3 abc.tif out.jpeg

Is there any way to preserve the resolution while creating image using GDAL ?


texts: White tiles with Google Chrome and OpenLayers 3

texts:
I created personal tiles on my webserver, which works with Apache.
These tiles are in folders from 0 to 16 in Jpg format.
I render these local tiles with OL3.15.1.
On Firefox, IE Edge and IE10 I've no problem in loading these tiles, but with Google Chrome i see blank tiles.

This is an example of the rendering.
The white tile what you see appear few seconds ago.


texts:
gdalwarp has -co TILES=YES (256x256 as default)

Can I set different tile size?


texts: Esri Geometric Network - Error Code 18 (unknown)

texts:
We have created a geometric network in a Personal Geodatabase with ArcGIS 10.2.2 for Desktop.

Each time we are getting an error code of 18 on a particular point feature.

As you can see here, there is no error code of 18 according to the Esri table.

We have submitted this to Esri but have not gotten a response.

Rather than just deleting the point and recreating it, we want to know exactly why this happened.

Has anyone ever seen a geometric network error 18 or know what this means?


texts: Iterative selection by attribute and then location using ArcGIS ModelBuilder?

texts:
I am trying to divide and record a road dataset using a GRID I just created. Is there a way to perform that using only the ModelBuilder or do I have to use Python (never tried before..)?

Here is below what I tried so far but it's not (yet?) working

For goes from 1 to 42 (the number of records in the GRID).
Select Layer By Attribute appears to work well using GRID_ID that goes also from 1 to 42. However I just reached an impasse, I don't know if the Select by location works or how to iteratively record the results.


texts: Georeferencing lat/lon .png map and adding grid using lat/lon?

texts:
I'm trying to input a .png map into my QGIS project for a small area in South Africa. I don't know the CRS used to create the map but it has a grid system on it with the lat/lon labelled (created using photoshop I think). I have numerous problems occurring:

I've tried to georeference it using the "from map canvas" option and I added in 17 different points. But when I added it as a layer to my QGIS map (for which I have already input some of the roads, water sources, landmarks etc as vector layers on top of Google Sat/ Open Streetmaps) it places the map as a tiny tiny spec in the middle of the sea near Guernsey (British Isles)! I have no idea how this could happen. Is it something to do with the scale? When I created the georef map I selected "Linear", "Nearest Neighbour" and I set the CRS to the same as my project: WGS84 EPSG 3857 (OTF). When I "Zoom to layer on the layers I've created that fit with Google Satellite map the scale reads 2:1, when I "Zoom to Layer" on the georeferenced raster layer created from the .png map it reads 1:1.
I could try and georef using the lon/lat on the .png map grid but they don't match up with the lon/lat when I hover over the same features on the map canvas. It's close but tens of seconds out (e.g. a landmark at E26•07'29.2, S33•30'27.3 on the png lies at 26.13072, -33.50735 on the QGIS map). The QGIS project is in WGS 84 Pseudo Mercator EPSG 3857 (OTF).
The other option is to recreate the grid used on the PNG map (because the grid reference system from this has been used to record data in the field for this project) in the QGIS project but then I hit the same problem with the lon/lat not matching. AND, being a relative QGIS newbie I don't know how to create this grid in my project. Any tips?

Unfortunately I cannot share the map with you.


texts:
I'm running QGIS 2.01 Dufour on Linux Mint. Data & project are WGS84.
I'm trying to smooth a grid & following other posts here I've used the Majority filter.  This is looking helpful, but the resulting grid is some 70km WSW of the original.

There aren't any other settings so I'm not sure what's happening & how to correct it.


texts: Classify trajectory compression algorithm

texts:
I'm tryng to classify each compression algorithm based upon their features, i've thinked:

Compression algorithm

Lossless algorithm

Batched algorithm

Rinex

Lossy algorithm

Batched algorithm

Uniform sampling
Douglas-Peucker
Bellman

Online algorithm

Opening window

Hybrid algorithm

Threshold algorithm

Do you agree with me? How can I improve this chart? The main division is among lossless and lossy or batched and online? Exist an online lossless algorithm?

Best regard


texts: Is there a way to automatically create a new polygon in an existing Feature Class with over 50'000 Vertices using ArcGIS Desktop 10.2?


texts: Add Basemap to ArcMap shows a blank window

texts:
I tried to add a base map to ArcMap with Adding Base map, but the window where types of base maps is blank.
What should I do?


texts: Smoothing/interpolating raster in Python using GDAL?

texts:
I am developing in Python and using GDAL from OSGEO to manipulate and interact with rasters and shapefiles.

I want to take a shapefile that has point features and interpolate it into a surface raster.  Right now I am using the method 'RasterizeLayer' which burns a value from the point feature into the raster (which is set with all nodata values) but leaves all untouched pixels as a 'nodata' value.  I am therefore left with a checkerboard type raster.

What I have after using RasterizeLayer:

What I want for a final product:

I believe the function I am looking for is known as 'Spline_sa()' from the arcgisscripting import.

Does GDAL have a similar function, or is there a different method to get my desired output?


texts: Setting the charset with GeoTools in Java

texts:
I have a well-made geojson file. Of course it is well made with shapefiles. I want to set the charset when creating the shapefile.
Below is part of the code.
File outFile = new File("D:\\geojson.shp");
outFile.createNewFile();
FileDataStore ds = FileDataStoreFinder.getDataStore(outFile);
ds.createSchema(outSchema);
SimpleFeatureSource featureSource = ds.getFeatureSource();

Where can I set the charset?


texts: Transparency for QuickMapServices imagery in QGIS 3

texts:
Like 30 minutes ago I changed the transparency on a Google satellite image from QuickMapServices. I did this by just opening properties and there was a slider for transparency. Now, properties just shows metadata. I don't know what I switched or did differently.
How can I adjust the transparency of these layers?


texts:
I'm attempting to install QGIS Server 2.8 on Windows Server 2012 R2. I've followed the instructions here and here. I've moved all the dlls from OSGeo4W to SysWOW64 for completeness' sake. I'm still getting a the following 500 error when I attempt to use GetCapabilities:

[Tue Mar 03 11:30:13 2015] [warn] [client 127.0.0.1] (OS 109)The pipe has been ended.  : mod_fcgid: get overlap result error
[Tue Mar 03 11:30:13 2015] [error] [client 127.0.0.1] Premature end of script headers: qgis_mapserv.fcgi.exe

When I attempt to run qgis_mapserv.fcgi.exe directly from bin, I get this message:

The program can't start because qscintilla2.dll is missing from your computer. Try reinstalling the program to fix the problem.

My httpd_qgis.conf is:

LoadModule fcgid_module modules/mod_fcgid.so

SetEnv PATH "C:\OSGeo4W\bin;C:\OSGeo4W\apps\qgis\bin;C:\OSGeo4W\apps\grass\grass-6.4.4\bin;C:\OSGeo4W\apps\grass\grass-6.4.4\lib;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem"
SetEnv QGIS_PREFIX_PATH "C:\OSGeo4W\apps\qgis"
SetEnv QT_PLUGIN_PATH "C:\OSGeo4W\apps\qgis\qtplugins;C:\OSGeo4W\apps\qt4\plugins"
SetEnv TEMP "C:\Users\ADMINI~1\AppData\Local\Temp\3"

Alias /qgis/ C:\OSGeo4W/apps/qgis/bin/

<Directory "C:\OSGeo4W/apps/qgis/bin/">
    SetHandler fcgid-script
    Options ExecCGI
    Order allow,deny
    Allow from all
</Directory>

Can anybody help me out with this error?


texts: How to fill Field Mappings parameter in script tool on updateParameters?

texts:
My goal is to get a list of fields choosen by an user from existing fields in feature class.
I think that I can show all fields in Field Mappings dialog, an user deletes unwanted fields and I get a required list.

The problem is how to populate Field Mappings when adding a feature class as a first parameter.
I can't select anything in 'Obtained from' property.
The code self.params[1].parameterDependencies = [0] in updateParameters function does't work in this case (it worked when 'Field' parameter data type was chosen).

What should I use to automatically populate Field Mappings when filling first parameter?

EDIT:
Fields list is applied as follows:


texts: Error : "filt_Thermal.expression is not a function"

texts:
I'm trying to create a simple mathematical formula (Thermal Condition Index - TCI creation) but I get an error message "filt_Thermal.expression is not a function"

Below is a part of the code script.

Any Ideas?

////////////  TCI CREATION ///////////////////////

// mask areas with no null values on Thermal band //

var Therm = L4578.select('Thermal');
var filt_Thermal = Therm.filterMetadata('Thermal',"not_contains",null); //****Thermal no null data*****//

var MinT = filt_Thermal.reduce(ee.Reducer.min());
var MaxT = filt_Thermal.reduce(ee.Reducer.max());

print(filt_Thermal);
////////////////////////////////////////////////////////
// Compute TCI using an expression.///////
var TCI = filt_Thermal.expression(
  "((MaxT - Thermal) / (MaxT + MinT))", {
  'Thermal': filt_Thermal.select('Thermal'),
  'MaxT': MaxT,
  'MinT': MinT });


texts: Encoding not active in Save vector layer as

texts:
I've seen some former questions regarding  encoding problems in QGIS, but I'm not able to find any answer for solution.
I'm a novice in QGIS 2.14(2.18) and want to convert an Esri Shapefile to GeoJSON.

Is there a simple solution out there?


texts: Like ArcGIS Server, is there a way to host, geoprocessing tools onto Geoserver?


texts: GRASS GIS code - equations used in the modules

texts:
How can I view the equations used in the GRASS GIS modules?
I found the code here:
1) URL: https://trac.osgeo.org/…/re…/raster/r.watershed/front/main.c;
2) URL: https://github.com/OSGeo/grass/tree/master/raster/r.watershed?fbclid=IwAR24KBPYl8iQjGQMphtl54dri5T0hU8cU5Q9DYycgAjeFG7RYQ8SVvAMn0Q
But not the expressions.


texts:
I'm using QGIS 2.10 (Pisa) and I can´t store spatial information on my MySQL database (.shp or geojson). In previous versions that was allowed.

It's not supported anymore or there are any plugins or solutions for this?

If it isn't possible with QGIS is there another way to do it?


texts:
I try to generate world coastline 1:30000 from ASTER's DEM with:

gdal_contour -a ELEVATION -fl 0

But above produce some of missing coastlines. Whats happening? Is it cliffy shore? How would you generate coastline?

Note: If I use 0.5 it will show all but I'm afraid it'd be inaccurate. Furthermore how to cleanup "tails" using v.clean?

I found ASTER mirror (mediafire) here: http://sasgis.ru/forum/viewtopic.php?f=21&t=1848&start=360


texts: Installing QGIS plugin from command line or Python?

texts:
I am looking for a way to install and activate plugins in QGIS without accessing the GUI. I have a QGIS instance running on a remote server where I run standalone Python scripts that process the data.

I would like to install a couple of plugins so that I can run their algorithms using processing.run(). Either a command line or from Python script solution would work for me.

I had no luck searching through the documentation. Any suggestions?


texts: Mapbox gl expression to get match in text field

texts:
I am trying to set one of the values from feature properties to text-field depending on a property

"text-field": [
                "match",
                ["get","label"],
                "L1","{name}",
                "{label}"
            ]

But it displays {label} or {name}, also try the same in maputnik.

The expression works fine for text-color and other icon-image property but there I am using hard-coded values after 'get' in setting icon-image like

"match",
["get","label"],
    "L1","house",
    "marker"

Is it possible to set values in expression with variable value? If Yes what am I doing wrong?

Or the support is only for hard-coded values?


texts: How would you do specific origins to specific destinations using network analyst in ArcGIS Pro?

texts:
I'm working in ArcGIS Pro 2.5 and I have an Advanced license.
There will be 2 datasets:

about 400 points for origins (ZIP centroids)
about 40 points for destinations (healthcare facilities)

I already have a ZIP polygon feature class containing the number of visitors by ZIP going to particular healthcare facilities. Because of this, I already know which combinations of ZIPs go to which healthcare facilities. I previously used this feature class for a map series project (data driven pages in ArcMap) and set a page definition query to only display the amount of visitors by ZIP for one healthcare facility at a time. I know I'll need to convert the ZIP polygons to centroids, but I'm trying to determine the best approach to use the dataset to calculate the distance and drive time from each ZIP centroid to each healthcare facility.
So far my thought is that I could use OD Cost Matrix, load my ZIP centroid locations, and load 1 healthcare facility destination at a time, then solve. I imagine it wouldn't take long for each run with that amount of locations, but I'd still need to do that x40. Is there a better way to do this? I was thinking Route, but I'm not sure it'd be any faster. Is there a quick way to do that with ArcPy? Basically, I want to calculate distance/drive time to each of the 40 facilities for all 400 ZIPs. I don't need the lines, just the table.


texts: Leaflet, wrong API key when using CloudMade tiles!

texts: I've registered on CloudMade and got some API keys but non of them work with Leaflet API. When I checked for image URLs and opened each directly using my browser it prints out the message "Wrong apikey". Anyone with the same issue?


texts:
I have a set of rasters within a file gdb in which are of continuous values (NDVI). I am trying to build an attribute table for each raster in order to reclassify into either 1 or 2 (water or land). I was able to get a model working on a single raster, but the iterator fails. Within the model I am using raster calculator with expression:  INT(("raster"+0.05)*100) to get to an integer, then using reclassify to get values either 1 or 2.
Model fails with a 000539 code "cannot concatenate str and flt".
Any solutions?


texts:
I have create some histogram using DEM as dataset and rasterio using show_hist to take histogram but I can't find some way to save this histogram as image.any idea?

import rasterio
from rasterio.plot import show_hist
src = rasterio.open("path/to/your/image.tif")
show_hist(
    src, bins=50, lw=0.0, stacked=False, alpha=0.3,
    histtype='stepfilled', title="Histogram")


texts:
Study Area: Manhattan

I'm measuring the street density using Street Network Grain size measure = Number of Street blocks per square mile. I have the NY street network but I do not have the map of Blocks.

Is there any place I can get the Street Block maps?

Alternatively, is the census block equivalent to a street block in Manhattan Borough.

I have the census block polygon shape file from TigerLine.


texts: Create a vector layer from a raster layer contour

texts:
I am using QGIS 2.18.
I have several sheets (about 430 MrSid raster files) that represents a full map. Each sheet is already geo-referenced.

I need to create a vector layer that represents the contour of each sheet.

For instance:

For this image I need to automatically create a square vector layer (polygon) that represents the 4 sides of the sheet.

Is there any way I can do it without having to manually set the coordinate of each point?


texts: Using lists to work with feature classes having different spatial references in ArcPy?

texts:
This is my first arcpy script attempting to use lists.

Input: 4 dif Excel files, each with a dif spatial reference

Output: 4 dif feature classes (in same geodatabase), each with original spatial reference converted to NAD 1983.

Issue: I can make 4 dif (but similar) scripts and have Python work for each input BUT is there a way to have Python go through my input list? The problem is that for the second step,  arcpy.MakeXYEventLayer_management, I don't know how to rotate through the spatial references depending on which Excel file I am using. Trying to use user suggested idea of sub-lists.

Updated Pasted script from Notepad:

# Import arcpy module
import arcpy
from arcpy import env

# Set workspace
env.workspace = r"E:\GIS\1.gdb\\"

# Set the spatial reference
sr1 = arcpy.SpatialReference("WGS 1984")
sr2 = arcpy.SpatialReference("NAD 1927")
sr3 = arcpy.SpatialReference("NAD 1983")

# Set variables
textPath1 = r"E:\GIS\Excel_files_by_datum\\"
textPath2 = r"E:\GIS\2015Q1\\"
textPath3 = r"E:\GIS\1.gdb\\"
input = [["WGS84.xlsx", sr1],["NAD27.xlsx",sr2],["NAD83.xlsx",sr3],["Long_0_or_blank.xlsx",sr3]]
out_Layer = "XY_Temp"
Layername = input[0:5]

#Run processes

for ss in input:
    try:
        print "Converting Excel file to table"
        # Convert Excel to table
        Table1 = arcpy.ExcelToTable_conversion(textPath1+ ss[0],textPath3 + Layername)

        print "Making XY event layer"
        # This is to take the xy values of the table and transform to points
        # Description: Creates an XY layer and exports it to a layer file
        XY_event = arcpy.MakeXYEventLayer_management(Table1,"LONGITUDE","LATITUDE",out_Layer, ss[0])

        print "Copying features"
        # Description: Creates geodatabase feature class from the xy layer
        FeatureCopy = arcpy.CopyFeatures_management(XY_event, Layername + "_temp")

        print "Making feature layer"
        # Description: Transforms xy event layer into feature layer so I can select from it
        FeatureLayer = arcpy.MakeFeatureLayer_management(FeatureCopy, Layername + "_temp2")

        print "Converting from original datum to NAD83"
        # Converts file from input datum to NAD83
        Transformed = arcpy.Project_management(FeatureLayer,textPath3 + Layername + "_to_NAD83",ss[2])

        print "Adding xy coordinates to feature layer table"
        # Adds new NAD83 xy coordinates to feature layer table
        arcpy.AddXY_management(Transformed)

        print "Deleting temp file"
        # Deletes temp FeatureCopy file
        arcpy.Delete_management(FeatureCopy)

        print "Deleting original table"
        # Deletes table from before the NAD 83 xy coordinates were added
        arcpy.Delete_management(Table1)

        print "Project complete"

    except:
        print arcpy.GetMessages()


texts:
I was planning to use Pythons is_land function, to differentiate between land and sea. However, after some inspection, I have major concerns in the accuracy. I can't find anything about this in the documentation, so I hoped anyone here could help me.

I initiate the basemap with high resolution, and a low area threshhold to help differentiate:

map = Basemap(projection='merc', resolution = 'h', area_thresh=0.001)

When I try this function, it returns true even though I choose points clearly not on land:

>>> map.is_land(39.784004,3.345337)
True
>>> map.is_land(39.789808,3.3395)
True
>>> map.is_land(39.799041,3.332291)
True
>>> map.is_land(39.863371,3.346367)
True

The three last ones is out at sea.

Anyone here that has used this function, and maybe got some tips to how I can make it more accurate, or if there is some (preferably) Python substitution, or other open source programmable solution to check if a number of points is at land or not.

Thought maybe I needed to map the points first, no better:

>>> map = Basemap(projection='merc', resolution = 'h', area_thresh=0.001)
>>> lat,long = map(39.784004,3.345337)
>>> map.is_land(lat,long)
True
>>> lat,long = map(39.789808,3.3395)
>>> map.is_land(lat,long)
True
>>> lat,long = map(39.799041,3.332291)
>>> map.is_land(lat,long)
True
>>> lat,long = map(39.863371,3.346367)
>>> map.is_land(lat,long)
True


texts: OpenLayers - How to construct OpenLayers.Bounds

texts:
I would like to create Bounds for a layer but I am not sure in what order I have to provide the min_x / max_x and min_y / max_y coordinates.

is it correct to put it in that order: min_y, min_x, max_y, max_x

var bounds = new OpenLayers.Bounds.fromArray([{{ wms.min_y }}, {{ wms.min_x }}, {{ wms.max_y }}, {{ wms.max_x }}, ]);


texts:
We're using ArcMap 10.0 sp5, creating a tool in c# using the ArcObjects sdk.

Is there a built in function or simple set of steps that calculates the area of each feature of a polygon layer within a specific extent?  What we want to do is calculate the area inside a set of bounds for each of the polygon layer’s features that reside within those bounds (defined by minimum and maximum X and Y).  This process would be repeated multiple times, as we traverse a grid.  Ideally, the function would also return the area not occupied by any features.

For example, consider this polygon layer in which there are 3 polygons (red, blue, and geen):

If we imagine splitting that layer into a grid:

Looking exclusively at one cell of the grid:

We would like to get a measurement of the area that each feature occupies within that cell, along with a measurement of the “empty” area of the cell. The measurements could be in actual area (square feet, square meters, etc.) or merely a percentage of the area of the grid cell (as shown below).

Note: these percents are for demonstration purposes only and are not necessarily to scale.

We'd also like to keep in mind the case of overlapping polygons. Consider this alternate polygon layer in which the blue polygon resides entirely within the red polygon:

In this case, the sum of the area covered by each polygon would be greater than the area covered by the grid cell.  As shown in the illustration above, red and blue both occupy the same percentage area as in the first example, but their areas are not distinct. In this case we would need to receive the values adding up to 110%, or a new set of percentages along the lines of:

Red = 31.8181818%
Green = 10%
Blue = 9.0909091%
Empty = 49.0909091%

We could either calculate the percentage as a fraction of the total polygon areas (including the "empty" polygon) or as a fraction of the grid cell area.

If a function exists that performs the calculations described above, we would need to know exactly what the result of that calculation gives us.

Our current thought is to follow the workflow below, but we wanted to see if anyone had better ideas.

Create a fishnet of the desired cell size and extent (to handle multiple grid cells at a time)
Union the fishnet with the polygon feature class
Calculate the area of all resultant features
Traverse the resultant features (by grid cell) to read the area of each unioned feature manually. (In this case, features without an FID from the original polygon layer would be the area not occupied by any features)
Sum the area of all features in the cell
Compute the percentage for each feature based on the calculated sum from 5.


texts: Diva-GIS CLM files missing projection, map units and datum

texts:
I have successfully created  Diva-GIS CLM files from tiff climate data using the two approaches below

1) Geotiff file --> Ascii grid file --> GRD/GRI  file --> CLM as explained by
 Julián Ramírez1 and Aaron Bueno-Cabrera(2009), Xavier Scheldeman and Maarten van Zonneveld (2010)

2) Geotiff file --> ASCii txt file --> GRD/GRI file  --> CLM

After testing the first approach, I discovered that key information i.e. projection, map units and datum were all missing in both CLM and GRD files.  When I tried running EcoCrop, I simply got a blank (grey) map with value = 0 on all the continents, though I could see variations on my map legend. May I also say that no data values in climate data were all set to -9999 by default

in the second approach, a WGS 84 coordinate reference system was assigned to ASCII txt file while importing into Idrisi software. As such all GRD and GRI files later created in Diva-GIS were projected (GEOGRAPHIC), had map units (degree) and a datum(WGS 84). However, CLM files only had projection but lacked map unit and datum. And again EcoCrop model simply produced a black map and showing variability in my map legend.

A major challenge for me is how to get a projection, a datum and map units on my CLM files.


texts:
I am using pgRouting on PostgreSQL 9.6, and for pgRouting. I need to run pg_createToplogy on the roads data, but it splits the roads at intersections and add source and target in respective columns.

Is there a way to avoid the breaking at intersection and populate Source and target column using pg_createTopology?


texts:
I'm trying to put a query on a vectorlayer with the current date.

The following code works, but I want the current date to be dynamic:

cast ("Starttijdstip" as character) <  '2018/03/01' AND  '2018/03/01' < cast ("Eindtijdstip" as character)

In 'Select by expression' I can use now(), is there something similar in the query builder (layer provider feature filter)?

The layer is a json-file that looks like this: {"type":"FeatureCollection","features":[{"geometry":{"coordinates":[[[105888.024, 194338.859], [105808.912, 194312.488], [105773.752, 194365.23], [105756.171, 194417.971], [105672.664, 194690.468], [105536.415, 195151.955], [105391.377, 195644.208], [105927.58, 194813.532], [105940.766, 194395.996], [105888.024, 194338.859]]],"type":"Polygon","crs":{"type":"name","properties":{"name":"urn:ogc:def:crs:EPSG::31370"}}}, "type":"Feature", "properties":{"....


texts: Alternative to Web Mercator projection that does not look too small on phone?

texts:
My issue with Web Mercator as a projection to use online is that I think it gives people an unrealistic perception of space. Greenland looking massive is a good example.

One benefit of Web Mercator, with Leaflet etc, is the projection is endless in each horizontal direction, meaning it's OK for small and large screens alike.

I've looked at using Robinson in D3, but it's going to look too small on phone.

Is there a viable alternative for the web that doesn't use the Mercator projection, but doesn't look tiny on phone, as I'm thinking the Robinson/Eckert projections might do?


texts: Find overlapping polylines in same layer in ArcMap?

texts:
How can I find overlapping polyline features in a layer in ArcMap without writing any code?

I have a PolyLine feature class in a personal geodatabase. It contains some features that overlap another polyline features.If I use "Select by location" menu to find these overlapped features, (suppose I have two different layers based on same featureclass) and use "Share a line segment with the source layer feature" from the dialog box in ArcMap, all features get selected because each feature overlaps with itself.

If I have 2 polyline layers in ArcMap based on one feature class, how can I find features from top layer which overlap with features of bottom layer that have different ObjectId?


texts: Looping through two raster folders to perform raster calculation gives ERROR 000732?

texts:
Last week I asked Looping through two raster folders to perform raster calculation? about a script to loop through two geodatabases and perform a raster calculation by matching the two rasters up based on their coordinates. This is my post for clarification:

"I have two geodatabases with rasters containing information about "treecover" and "loss". The file names are slightly different but can be matched based on the last 8 characters (the coordinates of each raster granule).See image

I can perform this simple conditional statement using either CON or RASTER CALCULATOR to retrieve all "Loss" data situated on pixels which have a value for "treecover" greater than or equal to 50, with 9999 being assigned as the output value if the statement is FALSE. The output raster is exactly what I want. I just need to do it for 137 pairs of rasters

RASTER CALC STATEMENT: con("treecover raster" >= 50, "Loss raster", 9999)"

The script so far looks like this:

import arcpy, os, math
arcpy.CheckOutExtension("Spatial")
from arcpy.sa import *
CVR = r"F:\Work\Aquifers_recalc\Final_recalc\Continent_Data\TEST\Treecover_TEST.gdb"
LSS = r"F:\Work\Aquifers_recalc\Final_recalc\Continent_Data\TEST\Lossyear_TEST.gdb"
# get first set of rasters
arcpy.env.workspace = CVR
cvr_rasters = arcpy.ListRasters()

# get second set of rasters
arcpy.env.workspace = LSS
lss_rasters = arcpy.ListRasters()
arcpy.env.workspace = r"F:\Work\Aquifers_recalc\Final_recalc\Continent_Data\TEST"
for cvr_ras, lss_ras in zip(cvr_rasters, lss_rasters):
    r1 = arcpy.sa.Raster(cvr_ras)
    r2 = arcpy.sa.Raster(lss_ras)
    result = Con(r1 >=50, r2, 999)
    out_name = "loss_{}.tif".format(cvr_ras[-8:])
    result.save(out_name)

I keep getting an error saying:

  ERROR 000732: Input Raster: Dataset
  Hansen_GFC2015_treecover2000_00N_010E does not exist or is not
  supported

I think something with my paths is wrong?

UPDATE: THIS ERROR WAS FIXED BUT WHEN APPLYING SCRIPT TO LARGER FOLDER I GET THIS ERROR:

Runtime error
Traceback (most recent call last):
  File "<string>", line 20, in <module>
  File "c:\program files (x86)\arcgis\desktop10.6\arcpy\arcpy\sa\Functions.py", line 269, in Con
    where_clause)
  File "c:\program files (x86)\arcgis\desktop10.6\arcpy\arcpy\sa\Utils.py", line 53, in swapper
    result = wrapper(*args, **kwargs)
  File "c:\program files (x86)\arcgis\desktop10.6\arcpy\arcpy\sa\Functions.py", line 256, in Wrapper
    ["IfThenElse", in_conditional_raster, in_true_raster_or_constant, in_false_raster_or_constant])
RuntimeError: ERROR 999998: Unexpected Error.


texts: Renaming ESRI default SHAPE_Length and SHAPE_Area fields

texts:
I have been working on a draft feature class that will eventually go into our production database, and I just tested it against my organization's standards, but it fails because the "SHAPE_Length" and "SHAPE_Area" fields that ESRI automatically generates were too long, had underscores, and were not all capitalized. These are requirements that my organization imposed on all field names.

Is it possible to change the name of these fields (not just the alias) to something like SHAPE.LEN and SHAPE.AREA?

So far, I tried running feature class to feature class and changing the name in field mappings, but that didn't work. I am using ArcMap 10.4


texts: Conditional reclassification of a raster

texts:
I am attempting to do a conditional reclassification of an NLCD land-use raster.

I specifically want to reclassify all developed areas (classifications 22,23,24) that are near a road (classification 21) into distinct new classes: "developed land near road".

My workflow so far using ArcMap has been:

Extract the road class into a new raster using "Extract by Attributes"
Convert that raster to point using "Raster to Point"
Buffer around those points using "Buffer"
Reconvert the resulting polygon back to a raster using "Polygon to Raster."  This file has a single value for being within distance of a road and NA's otherwise/
...
profit!

So step 5 is where I have trouble. I need to do some sort of a conditional reclassification on each of the 3 housing classes. In raster calculator I think I worked out that it needs to be of the form:

Con(IsNull("buff1_21_Buf60Rast"),"lu_1.asc",Diff("buff2_21_Buf30Rast","lu_1.asc"))

I'm suspecting that I will need to run it sequentially for each of the 3 housing values. But I'm not really sure how or which of the logical math operators to use.

Thoughts?


texts: Creating a line layer that links many points in layer to one point in another layer?

texts:
Let's say there's point layer A with 300 points and point layer B with one point

How to create a line layer that connects all points in layer A to the one point in layer B?

Using QGIS and/or PostGIS.


texts: Flattening topography while retaining structures in QGIS?

texts:
I have a set of Terrain data in both DSM and DTM form. What I am trying to do is extract the features (buildings, hedges etc...) that have been removed from the DTM, but I don't want the topography. The ideal end result would essentially be an elevation map of all the structures but on a flat plain rather than the rolling hills that are really there.

I have seen that the raster calculator could be used to extract all the parts of one set that are different to the other, but the bit I don't grasp is how I can then flatten the topography while keeping the relative height of the features.

I'm working in QGIS, but I also have access to LSS though I am not very experienced with it.


texts: pgr_dijkstra working but pgr_ksp but returning anything for the same params

texts:
The following returns a route as expected.

SELECT seq, id1 AS node, id2 AS edge, cost, b.the_geom as the_geom FROM pgr_dijkstra('
SELECT gid AS id,
     source::integer,
     target::integer,
     length::double precision AS cost
    FROM ways',
247542, 258349, false, false) a LEFT JOIN ways b ON (a.id2 = b.gid);

However the following does not. I expected this to return 3 routes but instead it returns nothing.

SELECT seq, id1 AS node, id2 AS edge, cost, b.the_geom as the_geom FROM pgr_ksp('
SELECT gid AS id,
     source::integer,
     target::integer,
     length::double precision AS cost
    FROM ways',
247542, 258349, 3, false) a LEFT JOIN ways b ON (a.id2 = b.gid);

Any idea why this is happening?


texts: Measuring feature within a feature to the nearest feature

texts: Is there a way in near tool to measure shortest distance of the input feature which is a point that is within the boundary of an island polygon to the nearest near feature which is also another polygon (squares) without passing to the island polygon? Attached here is an example. I use ArcMap 10.1.


texts:
I have a simple SQL query from my Cartodb account to populate a chart.

Here is the link

The chart works fine outside my company on a public network but I keep getting the following error when accessing it from inside my organization's network:

I think that I need to tell cartodb.js to use https when calling for the data. Can someone explain how I can do that?


texts: What is happening here ? I suspect the projection is wrong but it looks perfect at closer zoom

texts:
This is probably something that will be obvious to a more accustomed eye (I rely on it).

I am overlaying nils weidmann's cshapes (http://nils.weidmann.ws/projects/cshapes/shapefile.html), from geoserver via wms, over google maps, at https://www.degrit.com/hotw (does not work with Safari yet, Edge who knows).

While it would seem obvious that something is wrong with the projection while zoomed out, if you zoom in all borders overlay the map perfectly at any longitude/latitude.

I wish I had a better mastery of the jargon to formulate a better question, but... what gives ??

As a layman I would have thought the misalignment to exist at all zoom levels.

Further observations:

it looks like it's trying to wrap the layer around a spheroid as you zoom out
zooming out in geoserver's Layer Preview does not distort the layer, either with EPSG:900913 or EPSG:4326 (which presumably means it works fine in OL ? I'm going to put up a quick test page and see, but frankly it only makes things more confusing).
I'm sorry to say the quick test page (https://www.degrit.com/hotw/ffs.php) with OL works like a charm, without having to even specify a srs.

Edit re: hold/closure. While the original circumstances do no longer exist, I think if I post a couple of screenshots of the problem (which I can revert to easily) they, together with the self-answer I am going to accept as soon as it lets me, may spare some other poor soul a whole day of frustration.


texts: Can I use an Update cursor with a versioned feature class which has attachments in ArcObjects .NET

texts:
I have a problem with my code (C# ArcObjects 10.1). We are trying to update and insert 10 - 15 rows at a time into a feature class hosted in ArcSDE 10.1 on SQL Server 2008 R2.

We have a feature class which is versioned with move edits to base and also has attachments which are photos.

I did some proof of concept code a few months back and thought I had everything working - I had tested inserting and updating a versioned feature class and inserting attachments associated with a particular feature. Looking back, I don't think I tried these at the same time - the feature class I tested inserting attachments may not have been versioned.

The issue I am facing is that my code was working fine and inserting and updating features, as soon as I added the attachment table - it stopped working and I get this error :

Objects in this class cannot be updated outside an edit session     [SDE_CSO.DBO.DefinitiveList_COPY]

at this line :

IFeatureCursor cursor = featureClass.Update(queryFilter, true);

I am starting an edit session and edit operation before attempting this :

muWorkspaceEdit = (IMultiuserWorkspaceEdit)featureWorkspace;
workspaceEdit = (IWorkspaceEdit)featureWorkspace;

muWorkspaceEdit.StartMultiuserEditing(esriMultiuserEditSessionMode.esriMESMVersioned);
workspaceEdit.StartEditing(true);
workspaceEdit.StartEditOperation();

I did some googleing around and found a few old posts on the ESRI forums about a similar using using ArcPy and ArcObjects which seemed to suggest that using an Update cursor will not work with a table which is involved in a relationship.

So my question is.... is this possible with an update cursor - if so how? If not can someone offer an alternative solution?


texts: Successfully importing URLs from Access to ArcMap

texts:
I have an access database (2013 .accdb) with a column containing URLs. This field uses the hyperlink data type in access. I made an OLE connection to the database in ArcMap 10.3.1 but the URLs come in as BLOBs, which I understand Arc does if the data type length is over 255.
Is there another data type I should use? Is there another work around? I want my URLs to display in the attribute table.
So far I have tried to convert the datatype to Short Text in Access, but this adds a # to the beginning and end of the URL which makes it less simple to copy paste the URL.


texts: Location of Coordinate Systems folder in ArcGIS 10.1

texts:
To make it easier to find and select the 3 or 4 coordinate systems we use most often in ArcGIS 9.x and 10.0 we would copy them to the top of the Coordinate Systems folder, generally located in C:\Program Files\ArcGIS and thereby skip daily repeat navigation through all the categories to find the ones we want:

(The Favorite Coordinate Systems feature developed to accomplish the same aim isn't available in all locations (tools), and has to be set individually for every user profile. So, doesn't save as much work.)

ArcGIS 10.1 doesn't have this folder, or at least not in the same location. Where has it moved to, or is there another way to accomplish the same aim?


texts: Applying values to highest terminal segments in channel network using PostgreSQL?

texts:
I extracted a channel network from a dem but due to some technical difficulties the layer had some discontinuities. So after filling them, i suddenly realised that the Strahler orders it gave me were wrong and i want to create a query on Postgresql that might work around the issue for me. What i am trying to do right now is simple, get the segments placed highest in altitude at the end of a series of channels in the shapefile i made beforehand and apply to them a value of 1 in a column i created. In short i want postgre to read my shapes and find the places where he can't find another shape placed higher and intersecting with him.

I loaded my dem raster in PostgreSQL, and already used a query to extract the mean altitudes for each segment of my vector layer


texts: How to calculate surface area of highland region using DEM with ArcGIS (ArcEditor)?

texts:
Am shyaka from Rwanda.

I use GIS tools and have all required data to perform or calculate surface area from the polygons that have been given by GPS (Trimble) with ArcPad 8.

I originate from a high land region when I map a polygon with different hills, talwegs and when I tried to calculate the surface area using ArcMap in ArcEditor 9.3 just the area becomes too small compare to the decameter.

However, this area does not come from DEM (i.e. I did not use DEM to calculate the area).  It is a big problems for me to handle this issue of surface area. I need really your help.

It will be good if you can provide the procedures for how to do this.


texts:
I have a 350go GeoTIFF file with DEM data for the entire world. (a mix of SRTM, EUDEM, etc. ...)

This TIFF file is tiled with a block size of 256*256.

I would like to downsample this file to a lower resolution (original file resolution is  1295829, 464402)

I tried with this command:

gdal_translate -co NUM_THREADS=ALL_CPUS -r nearest -co BIGTIFF=YES -co
COMPRESS=LZW -outsize 0.1% 0.1% -co BLOCKXSIZE=256 -co BLOCKYSIZE=256 -co
TILED=YES world.tif downsized_world.tif

The output file resolution should be close to 1295 * 464

The problem is that it seems like it will take forever to complete (progress bar stuck at 0 for few hours) do you have any idea on how I could resample this file faster?

Resampling the file with an even lower resolution does not seem to make it go faster when for me it should be, isn't it? (Fewer pixels to read = faster resample?)


texts: Summary Within tool not matching Select by Location results

texts:
This seems like it should be simple but having trouble. Using ArcGIS Pro 2.4.

What I would like to do: count the number of polygons from one layer intersecting polygons in another. In this case, I'm counting the number of fires that have occurred in each county of the state. I would ultimately like to export a table the counts number of fires in five-year increments by county.

What I have done: I added a COUNT field in the fire layer, and used the Field Calculator to apply a value of one. Then I use the Summarize Within tool, grouped by each unique fire, to sum the values of the COUNT field. This 'works,' in that the operation is performed and I get a nice-sounding value, but the number is consistently off. When I have done a 'select by location' for fires that intersect a given county, the selected number is consistently higher than than the count yielded by the Summarize Within tool. If I do the Select by Location tool and change the relationship to 'Within' that number is also consistently higher.

Would like help on why this may be OR other suggestions for counting polygons based by their intersection of other polygons in another layer.


texts: Connect newly drawn lines to existing lines in QGIS?

texts: I need a simple tip for drawing line shapes in QGIS. I have multiple line shapes in my project that needs to be connected, so is there an option to join my already drawn line with the line that I'm drawing so they can have same connection point, but without zooming it to the max?


texts: matching georeferenced jpg with GPS data in WGS84

texts:
I have imported my georeferenced jpg which I believe (on the basis of metadata in xmml file) to be in the NZGD2000 TM coordinate system.

metadata:

Origin:
  1.76759e+06,5.94938e+06
Pixel Size:
  1.08167,-1.08182
No Data Value
  -32768
Data Type:
  GDT_Byte - Eight bit unsigned integer
Pyramid overviews:
Layer Spatial Reference System:
  +proj=tmerc +lat_0=0 +lon_0=173 +k=0.9996 +x_0=1600000 +y_0=10000000 +ellps=GRS80                         +towgs84=0,0,0,0,0,0,0 +units=m +no_defs
Layer Extent (layer original source projection):
  1767594.1269140779040754,5946587.8368053492158651 :         1770700.6877073212526739,5949380.0231113545596600

the waypoint data layer from the GPS
metadata:

General:
  Storage type of this layer: GPS eXchange file
Source for this layer: /Volumes/GARMIN/Garmin/GPX/Waypoints_19-JAN-13.gpx?type=waypoint
Geometry type of the features in this layer: Point
The number of features in this layer: 8
Editing capabilities of this layer: Add Features, Delete Features, Change Attribute Values
Extents:
  In layer spatial reference system units : xMin,yMin 174.891,-36.6086 : xMax,yMax         174.893,-36.6074
Layer Spatial Reference System:
  +proj=longlat +datum=WGS84 +no_defs

Clearly I need to convert the the GPS data to NZGD...

I first tried changing the coordinate system on GPS -- this displays the data on the GPS in correct coordinates but does not affect the exported data.

The import from GPS does not appear to allow one the specify any conversion.

I also tried changing the CRS of the layer but this does not appear to convert data just changes the interpretation of the existing coordinates.

Clearly I am missing something basic.

BTW using garmin's basecamp I was able to plot these points on google earth without problems so I know this is possible :)


texts: Saving geotiff in R - why resolution on x and y is not the same?

texts:
I have some data and i want to save it as a geotiff in R. This is not a problem but even if in my command line i set the resolution on x as 1 and on y as 1 after the geotiff is generated the resolution on x is 0.999 .... something instead on 1. Resolution on y is 1 as i set it previously. I saw same behavior in ArcGIS as well when i generate geotiffs form data. I am wondering why this happens.

Any explanation will be welcome.

PS. this time my raster in R has no projections - i have user define "coodinates" which can be considered metric.

Thanks,
Monica

OK here it is some generated data and the R code to generate the geotiff:

       set.seed(333)
    v1 <- rnorm(100, mean=0.23, sd=0.47)
    v2 <- rnorm(100, mean=0.17, sd=0.83)
    v3 <- rnorm(100, mean=0.34, sd=0.68)
    v4 <- rnorm(100, mean=0.59, sd=1.25)
    v5 <- rnorm(100, mean=-0.27, sd=0.91)
    v6 <- rnorm(100, mean=0.03, sd=1.37)
    test.m <- cbind(v1, v2, v3, v4, v5, v6)
    test.m <- t(test.m)
    r2a <- raster(test.m, xmn=1, xmx=dim(test.m)[2], ymn = 1, ymx=7, crs=NA)
    r2a

    class       : RasterLayer
    dimensions  : 6, 100, 600  (nrow, ncol, ncell)
    resolution  : 0.99, 1  (x, y)
    extent      : 1, 100, 1, 7  (xmin, xmax, ymin, ymax)
    coord. ref. : NA
    data source : in memory
    names       : layer
    values      : -3.397683, 4.136409  (min, max)

So, i expected to have resolution 1 x 1 and not 0.99 x 1. It is not really a big deal in the large scheme of things for what i am doing but i have to recognize - i am very curious why.

Thanks again,

Monica


texts: Mapserver - Error setting up simple WMS/Mapcache service

texts:
I've got a Ubuntu 12.04 computer with Mapserver and all other software on it. I have tried to set up a simple WMS / Mapcache service but have not succeeded. I can browse to the automatically generated demo page, and they work per se, but all I get are red tiles (i.e. broken)

I think there's something wrong in the configuration files, regarding referencing map or layers.

Mapcache.xml:  http://paste.org/67836

simple.map: http://paste.org/67837

I get this error message:

[Mon Oct  7 15:41:30 2013].708630 msWMSLoadGetMapParams(): WMS server error. Invalid     layer(s) given in the LAYERS parameter. A layer might be disabled for this     request. Check wms/ows_enable_request settings.
[Mon Oct  7 15:41:30 2013].708691 mapserv request processing time (msLoadMap not     incl.): 0.000s
[Mon Oct  7 15:41:30 2013].708712 msFreeMap(): freeing map at 0x18fa670.


texts:
I am working in c++/python/QT 4.5 with the api qgis 2.8.2

My application receive data from a communication port that indicate the change of position of an object diplayed on the map and represented by a svg ( an arrow )
the data received contains new position x and y and the rotation in degree

I want to rotate the symbol with the value received, if value equal 0 there is no rotation, if the value is 30 then rotate the symbol of 30 deg clockwise

I don't know how to do that, may be some of you had already work on that kind of point and share their procedure


texts: Increasing size of buffer based on field in ArcGIS for Desktop?

texts:
I am using vector data from a CSV file and ArcGIS.

I can use the Geoprocssing tool Buffer just fine, I use these parameters

and ArcGIS does produce what I want, however it is way to small (my data is extremely varied, lots of low and high numbers).

I can't seem to figure how I can increase the size of each circle equally?

EDIT: The numbers I am using are observed values, fairly certain they are ratio or at the very least interval. It's how many times a death occurred with-in a certain area during a specific year (the numbers in the second image are the different areas)


texts: Mapping latlng values to a point on a HRAP grid

texts:
I have a copy of some NWS rainfall data loaded into a PostGIS database.  Given a lat lng point, I want to find the rainfall for that given day.

  The original data are in XMRG format and projected in the Hydrologic Rainfall Analysis Project (HRAP) grid coordinate system, a polar stereographic projection true at 60°N / 105°W.

Based on a description of the HRAP system I found from the NWS, the calculations for locating a point on the HRAP grid based on lat lng value are as follows:

  RE = (EARTHR*(1+SIN(60)))/xmesh
  R = (RE*COS(xlat))/(1+SIN(xlat))
  WLONG = xlon+75
  X = R*SIN(WLONG)+401
  Y = R*COS(WLONG)+1601

  EARTHR is the radius of the earth (6371.2 KM)
  xmesh is the mesh length at 60° latitude (4.7625 KM)
  xlat is the latitude of point to be converted (decimal degrees)
  xlon is the longitude of point to be converted (decimal degrees)

I wrote up a quick javascript implementation to test it:

var deg2rad = function (deg) { return deg * (Math.PI / 180); };

var hrap = function (xlon, xlat) {
    var rxlon, rxlat, re, r, wlong, rwlong, x, y;
    var earthr = 6371.2;
    var xmesh = 4.7625;

    rxlat = deg2rad(xlat);

    with (Math) {
        re = (earthr * (1 + sin(PI / 3))) / xmesh;
        r = (re * cos(rxlat)) / (1 + sin(rxlat));

        wlong = xlon + 75;
        rwlong = deg2rad(wlong);
        x = round(r * sin(rwlong) + 401);
        y = round(r * cos(rwlong) + 1601);
    }

    return [x, y];
};

I ran a couple data points from the 2013-05-17 data set through to test it, with the following results:

Lng        Lat      NWS X  NWS Y  Calc X  Calc Y
 -76.5633  39.7478    958    571     369    2771
-124.6132  42.7528     34    572    -431    2308

Those numbers are nowhere close to correct, and I don't know why.  Is the document wrong?  Did I mess up the implementation?  Is the test data bad?  Am I missing a simpler solution?  I'd appreciate it if someone could point out where this is going wrong.


texts: Color blending/compositing in web mapping frameworks?

texts:
The color/layer blending capabilities of QGIS 2 produce marvelous results. Blended rasters are especially nice to look at. Blending is, to me at least, a better way of combining layers than mucking about with the transparency. I'm wondering how to achieve the same result in a web mapping framework.

Mapbox/TileMill supports a wide range of compositing operations but these don't work with base maps. I'm looking for a mechanism that does this in the browser. OpenLayers 3 seems capable of performing such operations but I can only find examples of how to dynamically control brightness/contrast. Maybe the rest is in the making?

I have a single-color raster that I want to blend/composite with the base map. I realize that blending changes the color but that's not a problem as I'm interest in perserving and communicating the saturation.

PS One of the options is to blend the layer and base map in QGIS, save as image, georeference image and upload to server as raster. This, of course, is a very undesireable way of proceeding.


texts: Enabling navigation tools when dialog is appeared on map?

texts:
I created a simple webgis with Navigation tools.The navigation tools is located in a dialog. the problem is when the dialog appeared on map, i couldn't interact with map and the background of dialog is disabled.

How can i enable the background ?

Is there any other options ( other forms,dialogs etc) to add tool in it?


texts: What do the response values from ArcGIS Rest API Elevation Profile function represent?

texts:
So I am trying to use the ArcGIS API and asked it to profile a route between two lat/longs:

(52.106505, 1.186008)
(52.113621, 1.246862)

My results are a series of points between the two and they should include an m-value and a z-value like this:

[52.106504999653112,1.1860080002471705,-5123,0],[52.10665022396023,1.1872499188943948,-5123,138.2728000000061]

Z-value for both is -5123 and the m 0 for the first point (as expected) but then 138.27. Now these two results are around 84 meters apart and my results tell me that distance is 84. So what is M? it seems to go up by about 138 each time so what is this a measure of?

Likewise and the real question I have is what on earth is Z? Because these points are not 5km below sea level? What is the Z values units and what is 0 relative to elevation? The documentation for this function doesn't seem to give any indication?


texts: Finding Z value difference between consecutive GPS points

texts:
I'm trying to abstract a value from a column with the next value from the same column in QGIS by using python.

I have a table with points with X,Y,Z from GPS tracklog. I sort them by time and I'm trying to find the Z value difference between points.

Any idea about how to do it?


texts: Sun ras format in ArcGIS 10.3 for Desktop?

texts:
I have some data stored in sun ras data. I found several pages that state this format is supported. e.g. http://support.esri.com/fr/knowledgebase/techarticles/detail/26784
I'm using version 10.3, which is not listed there, but I was guessing that if it was supported on earlier versions, it probably still is.
So I want to display the data using ArcMap. But when I want to add the data to my layer, they do not appear in the database where I stored them. In the "Add Data" window it says it will only show files of the type "datasets, layers and results", but in the pulldown menu I cannot choose an option that says "display all formats".
Any ideas on how to proceed?


texts: Displaying NorthArrow on ArcObjects axSceneControl?

texts:
I have standalone application (ArcObjects C# 10.3) uses axSceneControl.
How to display on the scene NorthArrow or Directional Arrow or something like that?
I found an example for NorthArrow http://help.arcgis.com/en/sdk/10.0/arcobjects_net/componenthelp/0049/00490000004w000000.htm but for IPageLayot.


texts: My click infowindow does not change for nearby points.

texts: My cartoDB map has several observations/points and sometimes they are clustered. I have infowindows setup for each point and it displays when I click on them. The problem happens when these points are close to each other. The window will popup for the first chosen point, but unless I close it or zoom in significantly, it will not automatically close and re-open for those nearby points when I click on them. It will work fine if I choose points located far away from each other. Please, any advice?


texts: Getting date from excel with xlrd as text in textelement?

texts:
when I run the script below in arcmap in the python window the date gets print
however I get the following error:Parsing error SyntaxError: invalid syntax (line 19)
the date isn't showing as text in textelement"survey"

what am i missing here?

from datetime import date,datetime,time
from xlrd import open_workbook,xldate_as_tuple
from arcpy import mapping

book = open_workbook(r"C:\Users\robert\Downloads\Hyrografie_2014_projectenlijst.xls")#excelfile

sheet = book.sheet_by_index(0)#eerste(0)blad

x =  int(arcpy.GetParameterAsText(0) ) #rij 3(0,1,2)!
survey = xldate_as_tuple(sheet.cell(x,6).value,book.datemode)#laatste opname

print date(*survey[:3])

mxd = mapping.MapDocument("current")
ellist = arcpy.mapping.ListLayoutElements(mxd,"TEXT_ELEMENT")

for el in ellist:
 if el.name == "survey":
  el.text = survey#line19


texts: Pasting elements into layer with Value Relation widget

texts: I have a layer, which contains data. Elements from this layer should be pasted into another one, which has value relation widget applyed to its columns. I'm missing values from the first (source) layer while trying to paste them into the second,even if quantity of columns and titles are similar in the first and second. The problem, I suppose, with data types. Can't find manuals or advices for such situation... Need links to read about it...


texts:
I want to show the cardinal direction at top of the map that shows the North direction like (a) section in the image below :

How can I do this?


texts: Memory error in python when reclassifying array

texts:
I have a .tif that I read into an array (call it tifArray), and I would like to classify the array based on set of conditions:

Where 1200 <= tifArray <= 4000, outputArray = 1
Where tifArray < 1200, outputArray = 2
Where tifArrary > 4000, outputArray = 3

I've tried both creating a new array (preferred) and replacing the values in place (see below) but I regardless I get a MemoryError. I've tried on machines that have 10 and 8 GB of free RAM. I've also tried using the np.where function and just plain indexing (below). I have no clue why I'm getting a memory error, and I don't think I should be running into that problem.

Some information about tifArray:

tifArray.shape = (55500, 55500)
tifArray.dtype = uint16

And here is one method I tried:

threshold_low = 1200
threshold_high = 4000
tifArray[(tifArray >= threshold_low) & (tifArray <= threshold_high)] = 1
tifArray[(tifArray < threshold_low)] = 2
tifArray[(tifArray > threshold_high)] = 3

The error:

File "./classify_segmented_fromAmplitude.py", line 90, in process_tile
    tifArray[(tifArray >= threshold_low) & (tifArray <= threshold_high)] = 1
MemoryError

When I comment out the first condition:

tifArray[(tifArray >= threshold_low) & (tifArray <= threshold_high)] = 1

and just run the following two lines, I get no Memory Error. So obviously the problem is with the multiple conditions, but I don't know how to get around it. Any ideas?


texts:
I'm using OpenLayers-3.6.0 in a web application. I have wfs layer as follow:

var url="http://localhost:8080/geoserver/wfs?&" +
      "service=wfs&version=1.1.0&request=GetFeature&typeNames=usa:states";
var format = new ol.format.WFS({});
var source = new ol.source.Vector({
    url: 'proxy.cgi?url='+ encodeURIComponent(url),
    format: format
});
layer wfs = new ol.layer.Vector({
    title: 'states',
    source: source
});

I edit this Point layer as follow:

draw = new ol.interaction.Draw({
    source: source,
    type: 'Point'
});

Now I want to save this layer in server side. In OpenLayers-2 we defined a saveStrategy and then call save method of it. It is shown as follows:

var saveStrategy = new OpenLayers.Strategy.Save();

/*
* change layer's features
*/

saveStratefy.save();

How can I do it in OpenLayers-3.6.0?


texts: Determining Longitude and Latitude of each corner of image

texts:
With this information below, including image size, longitude/latitude (of upper left I assume, maybe center), Resolution, and altitude - can I derive the Long/Lat of each corner of the image?

"size":[
    5472,
    3648
  ],
  "coordinateSystem":{
    "wkt":""
  },
  "metadata":{
    "":{
      "EXIF_BitsPerSample":"8 8 8",
      "EXIF_BodySerialNumber":"0K8TFCM0020857",
      "EXIF_ColorSpace":"1",
      "EXIF_ComponentsConfiguration":"0x01 0x02 0x03 0x00",
      "EXIF_Contrast":"0",
      "EXIF_DateTime":"2019:09:22 10:04:32",
      "EXIF_DateTimeDigitized":"2019:09:22 10:04:32",
      "EXIF_DateTimeOriginal":"2019:09:22 10:04:32",
      "EXIF_DeviceSettingDescription":"0x00 0x00 0x00 0x00",
      "EXIF_DigitalZoomRatio":"(1)",
      "EXIF_ExifVersion":"0230",
      "EXIF_ExposureBiasValue":"(0)",
      "EXIF_ExposureMode":"0",
      "EXIF_ExposureProgram":"2",
      "EXIF_ExposureTime":"(0.00625)",
      "EXIF_FileSource":"0x03",
      "EXIF_Flash":"0",
      "EXIF_FlashpixVersion":"0100",
      "EXIF_FNumber":"(4.5)",
      "EXIF_FocalLength":"(10.26)",
      "EXIF_FocalLengthIn35mmFilm":"28",
      "EXIF_GainControl":"0",
      "EXIF_GPSAltitude":"(63)",
      "EXIF_GPSAltitudeRef":"0x00",
      "EXIF_GPSLatitude":"(27) (47) (48.0588)",
      "EXIF_GPSLatitudeRef":"N",
      "EXIF_GPSLongitude":"(82) (19) (57.8939)",
      "EXIF_GPSLongitudeRef":"W",
      "EXIF_GPSVersionID":"0x02 0x03 0x00 0x00",
      "EXIF_ImageDescription":"default",
      "EXIF_Interoperability_Index":"R98",
      "EXIF_Interoperability_Version":"0x30 0x31 0x30 0x30",
      "EXIF_ISOSpeedRatings":"100",
      "EXIF_LensSpecification":"(28) (28) (2.8) (11)",
      "EXIF_LightSource":"1",
      "EXIF_Make":"Hasselblad",
      "EXIF_MakerNote":"[ae_dbg_info:\u0001\u0001",
      "EXIF_MaxApertureValue":"(2.971)",
      "EXIF_MeteringMode":"2",
      "EXIF_Model":"L1D-20c",
      "EXIF_Orientation":"1",
      "EXIF_PixelXDimension":"5472",
      "EXIF_PixelYDimension":"3648",
      "EXIF_ResolutionUnit":"2",
      "EXIF_SamplesPerPixel":"3",
      "EXIF_Saturation":"0",
      "EXIF_SceneCaptureType":"0",
      "EXIF_SceneType":"0x01",
      "EXIF_Sharpness":"2",
      "EXIF_Software":"10.00.11.04",
      "EXIF_WhiteBalance":"0",
      "EXIF_XResolution":"(72)",
      "EXIF_YCbCrPositioning":"1",
      "EXIF_YResolution":"(72)"
    },
    "IMAGE_STRUCTURE":{
      "COMPRESSION":"JPEG",
      "INTERLEAVE":"PIXEL",
      "SOURCE_COLOR_SPACE":"YCbCr"
    }
  },
  "cornerCoordinates":{
    "upperLeft":[
      0.0,
      0.0
    ],
    "lowerLeft":[
      0.0,
      3648.0
    ],
    "lowerRight":[
      5472.0,
      3648.0
    ],
    "upperRight":[
      5472.0,
      0.0
    ],
    "center":[
      2736.0,
      1824.0
    ]
  },


texts: Using PyProj/Programming to Convert Lat/Lon to X,Y on a Gnomonic Projection

texts:
As a preface, I'm pretty new to the world of GIS. I'm working on a personal project to create interactive event timelines over custom maps. Being I'd like to be able to intake a an event location (in Latitude/Longitude values) and place it at the correct point on a map, I'd need to be sure I knew how to convert those Lat/Lon values to the appropriate cartesian coordinates over map image I'm using.

Right now, I'm working with a Gnomonic projection of Europe centered on 51N, 15E, with a edge angle of 15 degrees (admittedly not sure what edge angle means, precisely).

I was originally using the formula laid out here (http://mathworld.wolfram.com/GnomonicProjection.html) to try and convert between lat,lon and x,y - but I'm realizing I have no idea how to take the output X,Y value and transform it into something I can use for this specific map (being it doesn't take into account the center being on Europe, or particular "zoom")

So, to get to the point - do you have any suggestions for programs/libraries I can use to do this conversion for a subset of a map projection? Right now I'm pretty lost as to what steps I'd need to take to get form point A to B - so even an outline of how you might approach the problem would be super enlightening.


texts: Leaflet: map.locate set maxZoom dynamically

texts:
I Update the position of the marker through the localization function.

However, the user might wish to zoom to a differed level, but when the position maker gets updated the map always zooms back to the value set in the locate maxZoom option.

Is there a way to change the maxZoom value dynamically depending on the zoom level the user has chosen?

var gpsMarker = null;
    var gpsCircleMarker;

    function onLocationFound(e) {
        var radius = e.accuracy / 2;
        var popupContent = "You are within " + radius + " meters from this point";

    if (gpsMarker == null) {
        gpsMarker = L.marker(e.latlng, {icon: IsyUserIcon}).addTo(map);
        gpsMarker.bindPopup(popupContent).openPopup();
        gpsCircleMarker = L.circle(e.latlng, radius).addTo(map);
    }
    else {
        gpsMarker.getPopup().setContent(popupContent);
        gpsMarker.setLatLng(e.latlng);
        gpsCircleMarker.setLatLng(e.latlng);
        gpsCircleMarker.setRadius(radius);
        }
    }

map.on('locationfound', onLocationFound);

map.locate({setView: true, watch: true, maxZoom: 16});


texts: How to select data according to specific dates

texts:
I am using QGIS Essen version 2.14.1, and I am trying to select specific data according to dates in the field calculator:

I am using the following formula but the system is telling me: syntax error, unexpected LE

Here is my formula:

case when
( "Copy of _4"  > 01/09/2016 and  "Copy of _5" < 18/09/2016)
 then 'Y' else 'N' end

Anyone know where I am going wrong?


texts:
In Arcmap and specifically using a WMS layer that I cannot access the attribute table of, how can I 'intercept' or extract the results from using the Identify tool from the toolbar? I would like to piggyback on the identify tool and use the results for my own means. This would be very handy for a WMS layer that I can't quickly get to the attribute table of. I could identify certain features and then route the feature information into a table for my own use.

With leaflet, I can do something similar by constructing a query against the WMS and using the returned json as feature data.

I hope that I am overlooking something or some tool so basic that already exists for this situation. If so, please let me know.

Added images after Alex' comment to show that the 'Select' option is greyed out. Also the Data > Export is not available for this WMS layer.


texts: Exporting vector tiles from Mapbox Studio?

texts:
Using MapBox Studio, I created a new tileset, uploaded a zipped shapefile and styled it. Now, I want to export vector tiles so I can self-host them. While searching, I found many indications that exporting vector tiles was possible but nothing explaining where or how to do it.

How do I export my data as vector tiles?


texts: Seeking historical (pre-war) data on cities and towns in Germany?

texts:
I'm trying to find and merge German city-level data from various time periods: ~1900, ~1930 and ~1990.

What's difficult:

Obviously some cities merged, new places were founded after 1900, and again others are in nowadays Poland or France. I am mainly interested in finding data on population densities and further demographics, but would need to know in detail whether some data point pertains to exactly the same unit of observations.

Example: Older data might have an entry for "Ebingen" in Baden-Württemberg. In 1975 Albstadt was founded and Ebingen became a part of Albstadt so more recent data will have Albstadt not Ebingen, but Albstadt also contains other places.

What I need:

Is there any public dataset available that

provides information on such changes,
provides pre-war demographics (population etc.), and ideally
links pre-war town names to today's municipality-IDs (GKZ)?


texts: How do I catch PostgreSQL/ PostGIS RAISE messages in OpenLayers?

texts:
Is it possible to catch Raise Warning, Raise Notice and Raise Exception in OpenLayers while using a WFS-T-Layer (stored in a PostGIS-Database) to save edits?
Example: A trigger is used to check values or check Intersections/Overlaps and gives back warnings or exceptions that are displayed in alerts/popups to give some feedback to the user.


texts: Catch click event on map, but on nothing else

texts:
My map has some stuff like points, lines, etc... and I want to remove some layers on the map when the user clicks on another part of the map, as follow:

map.on({
   click: function(event) {
      removePolylines.call(this);
      hidePopup.call(this);
   }.bind(this),
});

That removePolylines method, I wish to trigger it only when you click on the map, but not when you click on a line or point. How can I distinguish when click event is fired?
I mean, I want to remove the lines when you click on nothing else but the map.


texts: Pulkovo Transformation parameters in QGIS 2.18

texts:
I'd like to use a 7-Parameter transformation between Pulkovo Geodetic CRS (EPSG 4178) and ETRS89 Geodetic CRS (EPSG 4258) in QGIS.

There are different sets of transformation parameters for this task. I'd like to use Pulkovo to ETRS89 method with EPSG 1775 with the parameters 24.9, -126.4, -93.2, -0.063, -0.247, -0.041, 1.01.

QGIS offers exactly this parameters in the parameters-attribute in the srs.db in table tbl_srs (auth_id from 2397 to 2398).

But when I want to choose the transformation for displaying my data, QGIS offers me parameters for example for the method with EPSG-Code 1675 (see tbl_datum_transform in srs.db). It is an older method and the parameters offer less accuracy. QGIS does not offer the 1775-method here. It is not listed in the table tbl_datum_transform.

Why are the 1775-parameters in the tbl_srs table to define Pulkovo, but not as a method in the tbl_datum_transform table? Should I simply add it?
And when is QGIS using which transformation parameters (from which table)?
I guess I am not aware of the use of the srs.db in QGIS.


texts: Rules-based highlighted feature doesn't update when generating an atlas programmatically in plugin

texts:
I'm trying to export a set of Image based on an atlas define by my plugin.
Almost everything works well except that I have a rules based style on my coverage layer to highlight the current atlas feature as follow :

@atlas_featureid = $id

If I use my template composer inside QGIS the highlighted feature is updated for every map so everything seems right.

But when I generate the outputs from my plugin the highlighted feature does not update and stay always on the same feature... (no update)

Here is the code I use to instanciate and run the atlas:

composition = QgsComposition(renderer)
qpt_file = os.path.join(os.path.dirname(__file__), 'qpt','composer.qpt')
template_file = file(qpt_file, 'rt')
template_content = template_file.read()
template_file.close()
document = QDomDocument()
document.setContent(template_content)
composition.loadFromTemplate(document)
atlas_map = composition.getComposerMapById(0)
atlas_map.setAtlasDriven(True)

atlas = QgsAtlasComposition(composition)
atlas.setEnabled(True)
atlas.setCoverageLayer(layer)
atlas.setHideCoverage(False)

atlas.setFilterFeatures(True)
filtre = "\"{com}\"||\"{sec}\"||\"{num}\" in ({idents})".format(idents=idents,com=config['shp_mapping']['COM'],sec=config['shp_mapping']['SEC'],num=config['shp_mapping']['NUM'])
atlas.setFeatureFilter(filtre)
atlas.setFilterFeatures(True)
atlas_map.setAtlasScalingMode(QgsComposerMap.Auto)
atlas_map.setAtlasMargin(6.0)
atlas_map.setUpdatesEnabled(True)

atlas.beginRender()
composition.setAtlasMode(QgsComposition.ExportAtlas)

for i in range(0, atlas.numFeatures()):
     atlas.prepareForFeature(i)
     layer.triggerRepaint()
     feat = atlas.feature()

     exp_dir = os.path.dirname(QgsProject.instance().fileName())
     exp_dir = os.path.join(exp_dir,
                        config["relative_export_directory"],
                        feat[config['shp_mapping']['COM']])
     if not os.path.exists(exp_dir):
           os.makedirs(exp_dir)
     filename = feat[config['shp_mapping']['SEC']]+feat[config['shp_mapping']['NUM']]+'.png'
     out = os.path.join(exp_dir, filename)
     image = composition.printPageAsRaster(0)
     image.save(out)
atlas.endRender()

I suspect that I need to udpdate something for every rendered maps but I can't figure out what... The most weird thing to me is that it works fine when the atlas is exported from qgis GUI and this is the only problem I get in my resulting images when the atlas is exported from my plugin (the extent, scale, labels,... are fine). It's seems to be a style problem...


texts:
Im using Arcmap 10.1 version.I don't know where i made mistake my database.
I have attached an example image to show the Error Report.


texts: Decommissioning Raster Catalogs in ArcGIS for Desktop?

texts: Have heard news that Esri's road-map may include the decommissioning of the raster catalog. Can anyone confirm / deny this? Can't find any news articles online but we need to future-proof our systems architecture and we do not want to spend money purchasing Image Server. We have some great time series datasets of historical mapping using raster catalogs so I'm hoping my intel is wrong!


texts:
I've a GML file from the Ordinance Survey which includes a Cartographic Text layer which I'd like to load and render in QGIS.

The layer has attributes which are intended to be use for the font size, font type, its orientation, etc but it doesn't appear to be in an immediately useful format. For example, orientation is in 1/10's of a degree and font is simply an number between 1 and 3.

Setting aside loading the GML into PostGIS and replacing the fields with ones that may be more readily interpreted, I was wondering if there's a way within the QML structure to support more than one label type - for example, each symbol links to its own label section?


texts: Extraction of data from soil database using QGIS

texts:
I wanted to extract soil data from harmonised soil database (hwsd) for a small catchment using QGIS. Files that I have downloaded from hwsd database are in .bil,.hdr,.blw and Microsoft Office Access format. And I have shapefile showing boundary of the catchment.

Please give the procedure to extract data for my catchment from database using QGIS.


texts: Georeferenced Rasters from QGIS to ESRI: coordinate system problem

texts:
I have georeferenced rasters in QGIS (2.18). We assigned a coordinate system to the image: EPSG 26917, which is NAD83 Zone 17N. When i then bring this image into ESRI, the coordinate system is redefined as some custom projection called "UTM_Zone_17_Northern_Hemisphere" with a made up GCS but which otherwise matches the standard UTM 17 in ESRI.
What i can't understand is why it's doing this - the ID for the system is correct in QGIS, but ESRI won't accept it - even though ESRI also uses EPSG ID's and NAD83 17N is the same in both programs. Because the systems don't match, i can't then edit the rasters as i need to. I have to keep this bogus projection and re-project all my images as i go.


texts:
I am trying to set up a GIS database in QGIS (2.16.1) containing some geological information. I've created a shapefile (polylines) and added a map-tip to it which displays a cross-section related to the respective line (see image).

This works well as long as I use absolute paths in the attribute table of the shapefile, linking to the location of the cross-section.

BUT I would like to use relative paths because there is a chance that the folder containing the QGIS file, the shapefiles and the cross-sections will be copied to a different location.

I have tried but did not succeed and google and the search here did not help me. Can someone help me with that?

One more thing: Is there a possibility to re-size the map tip according to the size of the images? I know there is a way to set a fixed size but the cross-sections I am displaying have different sizes each time.

I am relatively new to QGIS and Python.


texts: Where can I find gridded Current Global Climate Datasets (Mean Temperature and Precipitation) at 30 second resolution?


texts: How QGIS shows "EPSG:4326 - WGS 84 - Geographic" for the GeoTIFF file's CRS, and how to reproduce it in GDAL and Python?

texts:
I have a GeoTIFF file (named avhrr.tif), and tried detect it's CRS in Python and gdal and compare it's values with that in QGIS. Here is a screenshot that is taken from the QGIS:

Here is the code that I used in Python:
from osgeo import gdal, osr

dataset = gdal.Open("avhrr.tif", gdal.GA_ReadOnly)
prj=dataset.GetProjection()

srs=osr.SpatialReference(wkt=prj)
print(srs)

which prints:
GEOGCS["WGS 84",
    DATUM["WGS_1984",
        SPHEROID["WGS 84",6378137,298.257223563,
            AUTHORITY["EPSG","7030"]],
        AUTHORITY["EPSG","6326"]],
    PRIMEM["Greenwich",0,
        AUTHORITY["EPSG","8901"]],
    UNIT["degree",0.0174532925199433,
        AUTHORITY["EPSG","9122"]],
    AXIS["Latitude",NORTH],
    AXIS["Longitude",EAST],
    AUTHORITY["EPSG","4326"]]

It seems that QGIS is showing GEOGCS's AUTHORITY which is ["EPSG","4326"] as CRS in the picture. Why is it so?
Why there is a 'Geographic' at the end of the CRS text that QGIS produces, and what does it say? How can I reproduce it in gdal?


texts: Computing convex hull of table using PostGIS Query in MapServer?

texts:
I am basically trying to compute the convex hull of a table in postgresql but I can't seem to get the query correct. My ultimate goal is to use this query as a polygon layer. The columns in the table i am trying to query contains:
the_geom, name, gid.

Here is my map file declarations:

 LAYER
 NAME         res
 DATA         res
 STATUS       ON
 TYPE         POLYGON
 DUMP    TRUE
 CONNECTIONTYPE POSTGIS
 CONNECTION "user=blue password=applesnoranges dbname=dappl host=127.0.0.1"
 DATA "the_geom from (SELECT ST_ConvexHull(ST_Collect(the_geom))
    FROM resturants) as blankers using unique gid using SRID=5570"
 CLASS
   NAME       "Resturants"
   STYLE
     COLOR        232 232 232
     OUTLINECOLOR 32 32 32
   END
 END

END

Here is my query statement:

    the_geom from (SELECT ST_ConvexHull(ST_Collect(the_geom))
    FROM resturants) as blankers using unique gid using SRID=5570;

Can someone tell me where I am going wrong?