texts:
I tried to use IFeatureCursorBuffer to create and dissolve the buffered features.I am trying to get the solution since some days using dissolve and UnionOverlappingBuffers, but not being able to get it.

Dim bc As IFeatureCursorBuffer
Dim bgpp As IBasicGeoprocessor
Dim ptempDS As IDatasetName
Dim ds As IDataset
Dim DissolveBufferLayer As IFeatureLayer
Dim pNewWSName As IWorkspaceName
Dim pdatasetname2 As IDatasetName
Dim tbl As ITable
Dim pfeatureclassname As IFeatureClassName
Dim BufferLayerName As String
Dim BufferLayer As IFeatureLayer

Set bc = New FeatureCursorBuffer
bc.PolygonBufferType = esriBufferOutsideIncludeInside
Set bc.featureCursor = BufferLayer.featureClass.update(Nothing, False)
Set bc.spatialReference = TTMap.spatialReference
bc.FieldDistance = BufferDistsanceInMeters
bc.Units(TTMap.MapUnits) = esriMeters
**bc.Dissolve = True**

Set bgpp = New BasicGeoprocessor

BufferLayerName = "DISSOLVE_" & BufferLayerName
CreateShapefile esriGeometryPolygon, ExportFolderPath, BufferLayerName, True

Set DissolveBufferLayer = GetLayerfromLayerName(BufferLayerName)
Set pfeatureclassname = New FeatureClassName
With pfeatureclassname
    .FeatureType = esriFeatureType.esriFTSimple
    .shapeFieldName = "Shape"
    .ShapeType = BufferLayer.featureClass.ShapeType
End With

Set pNewWSName = New WorkspaceName
pNewWSName.WorkspaceFactoryProgID = "esriCore.ShapefileWorkspaceFactory.1"
pNewWSName.PathName = ExportFolderPath & "\"

Set pdatasetname2 = pfeatureclassname
pdatasetname2.Name = DissolveBufferLayer.Name
Set pdatasetname2.WorkspaceName = pNewWSName

Set tbl = BufferLayer.featureClass
Set ds = tbl
Set ptempDS = ds.FullName

If Not tbl Is Nothing Then
    Set newtbl = BufferLayer.featureClass
    Set newtbl = bgpp.Dissolve(tbl, False, "ID", "ID", pdatasetname2)
End If

TTMxdoc.UpdateContents
TTMxdoc.activeView.Refresh

On Error GoTo 0
Exit Function


texts:
I have a raster data where pixel value of each cell represents the potential minimum travel time across the cell in old world.

Now, I need to find the minimum travel time of some points from Addis Ababa
(Ethiopia) in Arcmap. This needs to be the travel time on land (no seas or oceans). The raster data is missing values on seas and oceans.

In other words, I need the sum of pixel values on the route between a point and Addis Ababa, but only going on land.

Any suggestions on how to do this? Do you know any alternative methods to calculate migratory distance from Africa?


texts:
To use my data in fragstats i need to convert it into a signed integer grid.  I have the data in a raster format and have tried 'right click>data>export data> and setting the format to 'Grid' and it comes up with the error 'failed to save raster dataset'.  Any suggestions on how to convert either vector or raster data sets in to the format required for Fragstats?

Regards,


texts: What parameters are useful for an Albers equal area projection map of the world

texts:
I have a data set which contains global points.  I would like to convert from long/lat to Albers equal area.  However, the http://spatialreference.org proj4 world parameter values are actually for the USA.

Albers equal area might not be the best, both that is what I need to do.

Thanks!


texts: Explaining relevant info for non-tangent curve-Metes and Bounds-Traverse in ArcMap?

texts:
I'm trying to map out some meets and bounds from a zoning legal description. This is my fourth time using the Traverse tool for this (so still pretty new) and I'm completely thrown by the non-tangent curve descriptions. The best explanation I found so far is this but it doesn't cover enough.

So my question is this: What is the relevant info to enter in the ArcMap Traverse tool from the example below?

It reads like this:
"Along the arc of a non-tangent curve to the right, whose radius bears North 04 deg 54' 54'' East, said curve being subtended by a central angle of 23 deg 59' 42'', having a radius of 1382.70 feet and an arc length of 579.06 feet to a point of tangency."

My current guess is that something like:
 Curve Angle:23 deg 59' 42" Arc:579.06 Radial Direction: North 04 deg 54' 54" East Right

I want to get this right.


texts: I HAVE 6 Separate raster images for which i created a raster dataset. I am trying to cache this imagery to increase display performance.  How do you cache a raster dataset in arcmap?


texts: Naming clipped layer according to the attributes of the mask layer in QGIS

texts:
I have calculated the dnbr for a fire season across a whole region, and I've clipped it using a mask.
The mask is a layer of ground survey plot locations because I want to find out the dnbr for each plot. Each plot has a number under the field 'ID'. I have clipped the dnbr to each plot location but has returned (over 100 of) these new clipped files as 'new_clip'and a number irrelevant to the plot number. So I can't see which dnbr matches to which plot. I would like the new clipped files to look something like 'ID_247_clip'.
I've done this via Raster -> Extraction -> Clip raster by mask layer: input is Whole Region dNBR, overlay is plot locations. Then I've clicked the 'Iterate over this layer' button. It gives me exactly what I need, just with the wrong title for the clipped layers.
Is there a way to program the clip to name each layer according to the plot numbers in the ID field?
I've tried executing in batch mode but this doesn't work, as I only have one input and one overlay layer, whereas bulk seems to work for multiple input layers.
Also, a lot of the plot locations overlap, so I can't do anything like join by location.


texts:
I'm using python scripts on ArcGIS 10.2 to read excel files with information and put this results on attribute tables of the ArcGIS.

I know how to create a table, add rows, add fields and send information to tables.

from arcpy import env
env.workspace = "F:Tr/Model/Results"
output="Tr/Model/Results"
arcpy.CreateTable_management(output, "ger_rea.dbf")

#Create fields
arcpy.env.workspace = "F:Tr\Model\Results"
arcpy.AddField_management("ger_rea.dbf", "Barr", "Text", 50, "", "", "refcode", "NULLABLE", "REQUIRED")
arcpy.AddField_management("ger_rea.dbf", "Ge_1", "Float",  "", "", 10, "", "NON_NULLABLE", "NON_REQUIRED", "")
arcpy.AddField_management("ger_rea.dbf", "Ge_2", "Float",  "", "", 10, "", "NON_NULLABLE", "NON_REQUIRED", "")

table_ge_rea="F:Tr\Model\Results\ger_rea.dbf"

#Add rows
rows_pa = arcpy.InsertCursor("F:Tr\Model\Results\ger_rea.dbf")
for x in range(1, (L_Nod_name_LA+1)):
    row = rows_pa.newRow()
    rows_pa.insertRow(row)

#Put information on created table
gr=0
with arcpy.da.UpdateCursor(table_ge_rea,["Barr","OID"]) as cursor:
    for row in cursor:
        row[0]=Nod_name_GA[gr]
        row[1]=Act_L_value[ga]
        cursor.updateRow(row)
        gr=gr+1

However I need to create an automatically tool and The number os rows and fields of the excel tables can change and consequently tables that I'm creating with arcpy need to change too. For example: where I had a table with fields "Barr", "Ge_1", "Ge_2" I can have "Barr", "Ge_1", "Ge_2", "Ge_3", "Ge_4", etc...

How can I create a table (with arcpy) automatically, knowing the number of fields and rows (information on excel that I know how to read), using a for or while loop?

I tryed also use "arcpy excel to table" to export directly a sheet of an excel file to ArcGIS, using this code:

import arcpy
arcpy.env.workspace = "F:\Otim\inter"
arcpy.ExcelToTable_conversion("02_Reactiv.xlsx", "outger.gdb", "PoGenRe")

where 02_Reactiv.xlsx is the excel file, outger.gdb is the name of the output table and PoGenRe is the name of the sheet that I want to pass to ArcGIS.
This sheet contain: on the firts line only two columns filled, and Below, the information that I want to pass: 13 lines, 3 columns, 4 columns
in blank and 2 columns with sum of some values, etc..

It gives me an error:

  Runtime error  Traceback (most recent call last):   File "",
  line 1147, in    File "c:\program files
  (x86)\arcgis\desktop10.2\arcpy\arcpy\conversion.py", line 44, in
  ExcelToTable     raise e ExecuteError:  Traceback (most recent call
  last):   File "c:\program files
  (x86)\arcgis\desktop10.2\ArcToolbox\Scripts\ExcelToTable.py", line
  254, in      arcpy.GetParameterAsText(2))   File "c:\program
  files (x86)\arcgis\desktop10.2\ArcToolbox\Scripts\ExcelToTable.py",
  line 205, in excel_to_table     out_fields = gen_out_fields(workbook,
  sheet, out_path, is_gdb)   File "c:\program files
  (x86)\arcgis\desktop10.2\ArcToolbox\Scripts\ExcelToTable.py", line
  177, in gen_out_fields     out_fields.append(clsField(f, out_path,
  is_gdb, out_fields))   File "c:\program files
  (x86)\arcgis\desktop10.2\ArcToolbox\Scripts\ExcelToTable.py", line 32,
  in init     if not name[0].isalpha(): IndexError: string index out
  of range  Failed to execute (ExcelToTable).


texts: Route average, maximum and distance to maximum slope

texts:
I have a road network, consisting of a polyline shapefile, each record of its attribute table being a  stretch of the road network ("stretch" = any record of the attribute table of the polyline shapefile).

the maximum slope

This data should then be written on the attribute's table by creating a new field.

I'v searched the net looking for an extension or a plugin to do this in an automated fashion, but, apart from an extension for ArcGis, which calculates road slope in a very confusing way, nothing more was found.

So I ask and encourage the community for a solution, be it a plugin or any other method, especially that can be used with open source GIS programs like QGIS or MapWindow.

I also make available an old extension for ArcView 3.x, that uses a PolylineM class to find route slopes, and that can illustrate (or be a guide for) the way for a more updated plugin:

https://www.dropbox.com/s/gpkh6rhgrx8eqjc/route_slope_5_3.zip?dl=0


texts: Changing/editing original feature class referenced in ArcGIS map package?

texts:
I created two different map packages (say, mappack1 and mappack2) that included a common layer (polyline feature class in a file geodatabase, say LINE). Then I unpacked mappack1 and edited the common feature class and saved my edits but DID NOT save the .MXD file. I double checked the original feature class and verified the changes/edits. Although, when I opened the mappack2 and checked the original feature class inside of this unpacked map, the changes/edits did not appear in that particular feature class (LINE).

Could it be rooted in this fact that while creating a map package a new geodatabase has been created and after extracting the package it will go through the last generated geodatabase instead of the original one? But I actually double checked the original feature class to make sure about the edits!

Any ideas?!


texts: Reproject XYZ tile layer on the fly in Openlayers 3?

texts:
I have an Openlayers 3 application which has a default map projection of EPSG:27700 with both base layers and WFS layers using the same system as well as various mapping tools like measuring options.

I would like to add a base map layer which uses the Web Mercator (EPSG:3857) projection - after adding the layer as a new tile service, it does appear but there is a shift in where it sits on the map (due to the difference in coordinate system).

My question is, am I able to reproject this Web Mercator layer on the fly, without having to change my view projection?

I have provided a fiddle to a working example below - if you zoom right down to building level you will notice an approx 15 metre shift between base maps (https://jsfiddle.net/1bayd0ps/).


texts: Select Layer Attribute Management -SQL Query

texts:
I am trying to make a layer from schools that depicts schools at greater than 700 meters. There is an attribute field "ELEV_METER" that has the numeric value for elevation. The query keeps being rejected. I can do this in ArcMAP but need the python script to work. Any ideas?

arcpy.env.overwriteOutput = True

schools = "Schools"
highelevschools = "HighElevSchools"

arcpy.MakeFeatureLayer_management(schools, highelevschools)
arcpy.SelectLayerByAttribute_management(highelevschools, "NEW_SELECTION", "ELEV_METER" >= 700)


texts: Label background color depending on expression in QGIS print layout

texts:
I have a problem with the background color in a label in print layout in QGIS.
I would like to set the color of the label to be dependent on the data from the attribute table.

For example, when column A=1 the background will be yellow. When column A=1, green etc.


texts: Hand fitting curve and then applying to time series of rasters to make map

texts:
Maybe a data management problem, not too sure, but likely a challenge which someone has dealt with before.

I have a time series of rasters. I can summarise the information by taking averages of each raster and then plotting the averages with time (which is what is shown in the image). I also want to show a spatial representation and produce a map of the interpolated history on the polygon area of a site.

The green data points are the averages from each of the rasters. The fine dashed line is the expected/modelled performance. The red line with square data points is the hand fitted curve of what I "know to be true", something between the model and the measured values, an interpolation.

Unfortunately the relationship with time is not amenable to regression, at least not with any of the simplistic tools I use. Note that there is tail on the curve which the model shows but the lack of measurements at that time is ignorant of.

I would like the hand fitted curve/model to be modified by each of the rasters so that a final map can be created. The extent of variation is about 0.9 - 1.35 on the max values, this substantial when the whole lot are summed.

Experienced workers will recognise the feature being plotted, thats great, but I suspect it would be a common problem in many other disciplines as well.

I am looking for solutions I could implement in QGIS and GRASS.


texts:
Using ArcGIS Desktop 10, I need the histogram of the frequency to heights distribution like in the attached picture.

Is there another toolkit to access this data?

A screenshot is not suitable. The attribute table is not helpful, too.


texts: I have around 20-30 tiff files all georeferenced and I am trying to mosaic the data however I can't seem to remove the border of these historical scanned images. I have tried shrinking the footprint and I still can't get rid of the border. Any suggestions?


texts: How to apply WHERE clause to relationship class using ArcObjects?

texts: I'm trying to query objects related to objects and satisfying some query in ArcObjects. IRelationshipClass interface contains methods for getting all related objects but how can one filter them? I don't believe that such ability doesn't exist.


texts: How to deal with several markers in the same location on a map, e.g. to let viewers know they're there, and regarding tooltips with different info

texts:
I've created a web map. There are several markers on it, each representing something, and a tooltip shows related info.

Several markers are in the very same location (lat, lon).
So there are two problems:

you can't say how many markers are there actually, where you see a marker, one? Or 4, or... 1000?
you can't access the info for each marker, using the tooltip, because you can trigger only the top marker's tooltip.

How do you deal with this kind of situation?

I'm using Kepler.gl for Jupyter, so it would be nice to find a specific solution for it, but not necessary: I'm interested in understanding if there are some (technical and/or practical) solutions for this kind of cases, for web maps.


texts: QGIS: keep symbology for an intersection

texts:
In QGIS, I am doing a shapefile intersection (Vector > Geoprocessing Tools > Intersect) to keep only the points in a point layer that overlap with the polygons in a polygon layer.  What I'd like to do is have the option to save the original point layer symbology (which has been meticulously done and will be difficult to recreate) to the resulting intersected layer.  However, the intersected layer always ends up with 'default' symbology.  I've been searching around for the answer to this issue, but have not found it thus far.
Any pointer? I'm using QGIS 3.18 on a Windows 10 computer.


texts: Insert cursor only copies 80% of data due to lock?

texts:
I have two tables:

1) feature class (i.e. table in code) = sites under "SiteID" and mean july data under "JulyMean". The sites have duplicates, therefore there are several groups of same sites. There are other fields in this table. There are 280 sites(rows) in total.

2) summary statistics table (i.e. stat_table in code) = summary statistics table containing the sites under "SiteID" with max mean July data under "MAX_JulyMean". There are 23 sites(rows) in total.

I'd like to create a new feature class (i.e. newtable_path) which contains all the sites identified in stat_table with the maximum mean data, however i'd like to include the other fields from the feature class table. I used search cursors to match the site id from the stat table with the feature class table. Then i insert the feature class table's data into the new feature class table. The insert cursor only copies 19/23 sites into the new table (all 19 rows are in order meaning the insertcursor is writing as should). I've read that the problem is due to locks etc... but I don't know how to release the lock.

How do I have all 23 rows copied instead of just 19?

#import packages
import arcpy from arcpy
import * from arcpy
import env from arcpy.sa
import * import os
arcpy.CheckOutExtension("Spatial")

#Input
workspace = r"C:\Research\Water_Temperature_Analysis\Water_Temperature_80PercentOfJuly.gdb"
table =r"C:\Research\Water_Temperature_Analysis\Water_Temperature_80PercentOfJuly.gdb\DFOSLC_80andabove"
field = "SiteID" # field containing groups
field1 = "JulyMean" #field with max and min
stat_table = r"C:\Research\Water_Temperature_Analysis\Water_Temperature_80PercentOfJuly.gdb\DFOSLC_80andabove_extremeMaxMin"
    newtable = "DFOSLC_80andabove_ExtremeMeans"

    #enter workspace folder
    env.workspace = workspace
    arcpy.env.overwriteOutput = True

    #Find max and min
    #arcpy.Statistics_analysis(table, stat_table, [[field1, "MAX"],[field1,"MIN"]], field)
    # Create table with max and min
    arcpy.CreateFeatureclass_management(workspace, newtable, "POINT", table)
    newtable_path= workspace + "\\" + newtable

    # Copy Max Values to new table
    cursor = arcpy.SearchCursor(table)
    maxfield = "MAX_"+ str(field1)
    cursor1 = arcpy.SearchCursor(stat_table,[field,maxfield])
    cursor2 = arcpy.InsertCursor(newtable_path)
    for row1 in cursor1:
        for row in cursor:
            if row1.getValue(field) == row.getValue(field):
                if row1.getValue(maxfield) == row.getValue(field1):
                    cursor2.insertRow(row)
                    row1 = cursor1.next()
    del cursor2
    del row, cursor
    del row1, cursor1


texts: Need to hyperlink my personal data to a shapefile

texts: I want to hyperlink my personal data like Excel file to a shapefile. Can I do it in QGIS?


texts: How to speed up the process of vector data visualization for a web application

texts: I have a GIS web application and vector data that is going from the model to the web application. For developing the User Interface I am using JavaScript and OpenLayers. But sometimes the amount of geospatial data that I need to simultaneously visualize on a map is very big (10 000+ objects) and the browser cannot respond to all user requests. So, how can I speed up the process of visualization (both model and UI part) of large amounts of geodata?


texts:
I want to obtain the size of unchanged, decreased, and increased area etc (just like shown in image below) from 2 classification images in 2000 and 2007.
How do I do this in ERDAS?
.


texts: ArcMap 10 How to create a tool to use with a Vb.Net script?

texts:
I have a VB.net scrip that I would like to run from the toolbar.  In VBA, you would create a buttton that would collect the xy coordinates and pass the variables to the script for running.  I can't seem to figure out how to pass the variables.  When i create a button and click, the script ask for the variables before I have time to click the map.

Here is an example of the script I am using:

Creating StreetView/Bing Bird's Eye Add-In?

Thanks a bunch!

Heather


texts: How to update tile source URL at zoom change

texts:
I'm using MapServer tile mode with OpenLayers 5.3

new ol.layer.Tile({
    source: new ol.source.XYZ({
        url: 'http://localhost/cgi-bin/mapserv.exe?' +
            'map=mapfile&' +
            'mode=tile&' +
            'tilemode=gmap&' +
            'tile={x}+{y}+{z}'

My feature's rendering depends on zoom level, so I also need to append '&zoom=x' to the URL at runtime.

I know that the URL can be udpated with setUrl function, but what event handler should it be called in?

I've tried putting it into layer 'precompose'/'postcompose' events but they are triggerd abount a hundred times at one zoom change which I guess will impact performance much and calling getZoom() within these events may return zoom as double value like this

6
6.136041053939759
6.25823414964095
6.381397353723196
7

whereas only int value is expected.


texts: Update Parcel Records with Values from Other Parcel Feature without using Join or Field Calculate

texts:
We have a model/script that is set to run on a weekly basis, and is meant to update our parcel records using the parcel records from our county. Our parcels are stored in an SDE geodatabase version 10.2.2. In a nut shell, this model/script follows these steps:

Download county parcels as a feature class in a file geodatabase from an FTP site into a file geodatabase on our server.
Rename two of the fields in the county parcel feature class.
Use Join Field to join the county parcel feature class to our parcel feature class in the SDE geodatabase using the parcel ID field.
Run through a number of field calculate steps that recalculates the town parcel ownership field with the data in the county parcel ownership field. This process continues and updates other relevant fields including owner address, assessed value, deed number, etc.
The last step after completing about 15 field calculates is to delete all the county parcel fields that were added to the town parcel feature class during the Join Field.

This may not be the most efficient method but it has worked for us, until now. Twice within the last 6 months I have received an underlying DBMS error when running the model. This error states that Cannot create a row of size 8063 which is greater than the allowable maximum row size of 8060. Working with Esri and our IT, we discovered that this error can occur when large, fixed-width columns are dropped, like the ones that are dropped in step 5 of my model. The solution is to simply rebuild the parcel table using a SQL command.

Is there a different way to automate the update of the fields in our parcel feature class using the county parcel feature class without performing the join command?

Removing the join step should remove the need to delete the added fields, which in turn should remove the row size error we are receiving.

Is there a more efficient method we could be using to update our parcel data?

Another factor in this process is that when the join is performed, we never end up with a perfect 1-to-1 match because we maintain some parcel records that the county does not. In this case, during step 4, I use the following expression to make sure that if a join was not found our current data will not be calculated with Null values from the county; instead our parcel will just keep whatever existing data is currently in that record:

Dim X
if IsNull ([PIN_18]) then
    X = [Owner_name]
else
    X = [Owner]
end if

Owner_name refers to our records, while Owner and PIN_18 refer to the county's records. These fields change accordingly for whatever field is being calculated at the time.


texts: Getting (X,Y) projected coordinates of point instead of its longitude and latitude in ArcPy?

texts:
I am reading a shapefile through ArcPy. The shapefile has both geographical coordinate system and projected coordinate system. When I try to get the coordinates of a point geometry in the shapefile, the  result is always the point's longitude and latitude.

How could I get its projected coordinates?

The code are as follow:

        sr = arcpy.Describe(shp).spatialReference
        print (sr.name)
        with arcpy.da.SearchCursor(shp, ["SHAPE@"])as lines:
            for line in lines:
                s = line[0].getPart(0)
                for p in s:
                    print(p.X)

the output:

WGS_1984_UTM_Zone_18N
-72.5049105
-72.505729
-72.5058427
...

It looks the shapefile has a projected coordinate system. I am wondering why the points are still recorded with its longitude and latitude.


texts:
In QGIS 3.14 I wish to clip a layer to the features within a circular area.
Can this be done?


texts:
I cannot check in data from ArcPad. The reason is because in the ArcPad the gdb file does not appear. Only the map file appears and it is not recognized with the gdb file that is in ArcGIS.

Is there a way to convert to convert the amp file to a shapefile or a feature class?

I am using ArcPad for data collection. When a new feature or polygon is created in the field and checked in the database the polygon appears good. When we go out again and do more data collection and create other new polygons and check the data again all the new polygons will appears plus the ones done the previous week and appear as duplicate. I don't know why this is happening and I have to go one by one deleting them because it gives me and extra acreage.

What can I do?


texts: Objects created with "arcpy.LayerToKML_conversion" are shown in Google Earth Places with [no name]

texts:
When I create a kml file from an ArcGIS Pro layer using "arcpy.LayerToKML_conversion" all objects are shown in Google Earth Places (left pane) with [no name]. The piece of code doing this is as simple as this:

fc_node_live_available = os.path.join(working_folder, 'DATA\Optimity_Equipment.gdb', 'Node_Live_Available')
kml_node_live_available = os.path.join(out_path, 'Node_Live_Available.kmz')
arcpy.MakeFeatureLayer_management(fc_node_live_available, 'Node Live Available')
arcpy.LayerToKML_conversion('Node Live Available', kml_node_live_available, is_composite = 'NO_COMPOSITE', ignore_zvalue = 'ABSOLUTE')

However, when I do the same thing using the tool box ('Layer to kml' tool). Objects will show their name in Google Earth when importing the kml file.

Is there anything I am missing on my arcpy code?


texts: Planetary Reflectance vs Relative Spectral Response

texts:
I am confused between a Planetary Reflectance and the Relative Spectral Response (RSR). What I know/guess is that RSR is a response/function of an Instrument band's reflectance against a spectral range.

Isn't that reflectance the Planetary Reflectance?

I am trying to solve this problem:

  If the soil spectra was obtained at 10:20 am in January 5, 2005 at 14°
  20’ N 121° 13’ E, compute for the spectral radiance of soil at a) sea
  level, b) extra-terrestrial level. On this day, the Landsat ETM+
  satellite passed over the area. Neglecting atmospheric effects, what
  is the possible radiance detected by the sensor in the four bands?

I am given with:

Solar Irradiance values in a) Sea Level and b) Extra-Terrestrial Level which is also a response/function against a range of wavelength.
RSR for Landsat-7 ETM+
Spectral Signature of soil which is also a reflectance function/response against a spectral range.

Using the reference below, I need to compute for the Spectral Radiance Lλ.
I can use the RSR and and Solar Irradiance to compute for Mean Solar Exoatmospheric Irradiance, Esunλ. The Earth-Sun distance d has a Julian Calendar table while the Solar zenith angle θs can be computed using the given date and time in the question.

Where can I get the Planetary Reflectance to solve this problem?

Is it the reflectance for a wavelength in the RSR?

Reference:

IKONOS Planetary Reflectance and Mean Solar Exoatmospheric Irradiance


texts: Creating multiple buffers in a loop in GEE

texts:
I would like to do 50 buffers from a known point. I know to do one by one, but I would like to do in a Loop. Is there any way to do it?
This is part of my code:
var buff1 = ee.Geometry.Point([-46.633286, -23.550510]).buffer(1000);

var buff...n= ee.Geometry.Point([-46.633286, -23.550510]).buffer(...n);

var buff50= ee.Geometry.Point([-46.633286, -23.550510]).buffer(50000);

var interval = 1000;

var outline = ee.Image().byte().paint({
  featureCollection: [buff1, buff...n, buff50],
  color: 1,
  width: 1
});

Map.addLayer(outline, {palette: ['red']}, 'buff1');


texts: How to cite Geospatial Data that has been edited?

texts:
I used data from the Ordnance Survey for some maps I created. License information for the Ordnance Survey says to cite OS data like this:

Contains Ordnance Survey data © Crown copyright and database right [year]

and can be found at this link: www.ordnancesurvey.co.uk/opendata/licence

I'm glad to use this citation, but I edited the data I downloaded a bit. What's in my maps differs from what I actually received from the OS. Should I say in the citation that the geospatial data is derived from data received from the Ordnance Survey? If you don't have an authoritative answer, I also welcome thoughtful responses. Thank you.


texts:
I have a map working using Leaflet as follows, using EPSG 2236 and a custom tilegrid.  I want to switch to OpenLayers 3 so I can use the map rotation functionality but I am having trouble setting up the projection.

var bbox = [0, 5000000, 14747959, 19747959];
var maxResolution = ( bbox[2]-bbox[0] )/256;

var crs = L.CRS.proj4js('EPSG:2263'
                         , '+proj=lcc +lat_1=41.03333333333333 +lat_2=40.66666666666666 +lat_0=40.16666666666666 +lon_0=-74 '
                         + '+x_0=300000.0000000001 '
                         + '+y_0=0 '
                         + '+ellps=GRS80 '
                         + '+datum=NAD83 '
                         + '+to_meter=0.3048006096012192 '
                         + '+no_defs ',
                         new L.Transformation(1,-bbox[0], -1, bbox[3]));

   crs.scale = function(zoom) {
       return 1 / (maxResolution / Math.pow(2, zoom));
   };

In particular, how can I replicate the flipping of the axis achieved using this?:

new L.Transformation(1,-bbox[0], -1, bbox[3])


texts: Raster to shapefile results in polygons with no difference in values

texts:
I am trying to convert a 32bit floating point raster in tiff format to a vector .shp file in ArcMap. In particular, I have been attempting to convert my continuous data set found in the TIFF extension into a shapefile. The data contains bluespot depths.

I tried Raster to Polygon but the output gave a polygon with no difference in values. How can I get the values into the shapefile?


texts:
Is there a way to get similar raster styling in QGIS as ArcGIS does with classified raster data based on percentile scores? In other words, I want an equal number of pixels in one color for my entire raster. I already tried all settings for pseudocolor in QGIS. QGIS 2.12.1 Windows

In ArcGIS this functionality can be found in Layer properties - Symbology - Classified - Classify - Quantile

This is easy with shapefiles but not evident to me with raster files

UPDATE: I started working on a plugin but ran into problems: Quantile in QGIS python Plugin

Dialog window in arcGIS

Classes in Histogram for equal interval setting

classes in histogram for quantile (Equal number of pixels in class) setting


texts:
When I open QGIS, and use the tools, setting -> project properties, QGIS will crash.

When I also use the setting -> option -> CRS , Select new CRS also causes a crash.

It looks like couldn't use the Coordinate Reference System Selector.

Can I fix it by myself?


texts: Writing nearest neighbor distance to initial table in PostGIS?

texts:
I would like to mimic the ArcGIS near tool behavior is PostGIS.

Two tables, A and B. For each entry in A I want the distance of its nearest neighbor in B written to the field 'A.neighbordistance' which already exists in A. So far I have been able to come up with the below code which basically returns what I want. But because of my newness to postgis I have been unable to write the results to table A.

select
    distinct on(A.id)
    A.id as A_id,
    B.id as B_id,
    ST_Distance(A.geom, B.geom) as dist
from A, B
order by A.id, ST_Distance(A.geom,B.geom)

Other related posts/links:

Nearest Neighbor calculation in PostGIS? does not write the results back to table A
Nearest Neighbor in PostGIS is about php, and also does not write the results back to table A

How can I adjust my query (or a different one that might be better) to write the nearest neighbor distance back to table A?

Using:

pgadmin 4
postgis 2.4.3 (note, no tag exists yet for this version?)
pgsql 100


texts: I have a shapefile layer which comprises of a series of lines which represent archaeological features. I cannot delete individual lines as the delete button is greyed out. Is there a way for me to delete an individual object as I note the button is greyed out on other layers (polygons & dots). Incidentally, cut, copy and paste buttons are also greyed out.I'm using QGIS version 2.6 on aMac running Yosemite.


texts:
I'm trying to use ArcPy in order to change the layout of many Imagine files in my MXD.

Import Symbology from a layerfile does not seem very straightforward to me when using ArcPy (see this earlier question) so I'd like to try and use 'Apply symbology from layer' and base the symbology on a single img file for which I change the symbology by hand.

The script runs without raising any errors, but my symbology does not change.
I figured this might be because the Imagine files are automatically interpreted as 'stretched' when imported, but the symbology I want is based on 'Unique values'.

Is there an easy way to compute these unique values using ArcPy?

I know how to do compute them in the Properties box, but I'd rather include it in my script, since there are many Imagine files and its likely that I'll have to rerun it with new files that have different filenames.

The script adds data by looping over a bunch of files and it would be great if the symbology is automatically applied right away.

~~~
# import modules
import os, arcpy

~~~
# One-off actions

DIR = r"C:\imagine"
mxd = arcpy.mapping.MapDocument("CURRENT")
data_frame = arcpy.mapping.ListDataFrames(mxd, "Map series")[0]
target_group_layer = arcpy.mapping.ListLayers(mxd, "Geological Maps", data_frame)[0]
symbologyLayer = "example_symbology.img"

~~~
# Actions for each grid

for filename in os.listdir(DIR):

    if filename[-3:] == 'img':
        # importing the data
        add_layer = arcpy.mapping.Layer(filename)
        arcpy.mapping.AddLayerToGroup(data_frame, target_group_layer, add_layer, "BOTTOM")

        # setting the symbology
        arcpy.ApplySymbologyFromLayer_management(add_layer, symbologyLayer)

I'm running my code from the Python window within ArcMap 10.6.1.


texts: Tilecache seeding with mapserver doesn't generate tiles

texts:
I'm attempting to seed my tile cache on the server for use within OpenLayers for a few zoom levels, however the script doesn't seem to be working at all and everything I try I just get the same output.

The data displays fine when I view it in a browser using OpenLayers and the cache is generated based on what I look at.

The server is running Ubuntu 12.04.1 LTS which has nothing but Mapserver, Apache, Tilecache, and the required libs for that installed on.

My config files are as follows -

Tilecache Config

[cache]
type=Disk
base=/home/tilecache

[streetview]
size=256,256
srs=EPSG:27700
type=WMS
url=http://localhost/cgi-bin/mapserv?map=/home/mapadmin/data/tm/out/comp/tm.map
layers=streets
mapfile=/home/mapadmin/data/tm/out/comp/tm.map
bbox=600000,200000,660000,30000
extension=png
mime_type=image/png
maxresolution=234.375
extent_type=loose
levels=20
expire=3600

Mapserver Config

MAP
        IMAGETYPE       PNG
        EXTENT          600000.000000 200000.000000 660000.000000 300000.000
        SIZE            800 600
        SHAPEPATH       "/home/mapadmin/data/tm/out/comp/"
        IMAGECOLOR      255 255 255

        PROJECTION
                "init=epsg:27700"
        END

        WEB
                METADATA
                        "ows_enable_request"   "*"
                        "wms_title"             "WMS Street Test"
                        "wms_onlineresource"    "http://192.168.1.126/cgi-bin/mapserv?map=/home/mapadmin/data/tm/out/comp/tm.map&"
                        "wms_srs"               "EPSG:27700"
                END
        END

        LAYER
                NAME            streets
                STATUS          on
                TYPE            RASTER
                TILEINDEX       "tm.shp"
                TILEITEM        "LOCATION"

                PROJECTION
                        "init=epsg:27700"
                END

                METADATA
                        "wms_title"     "Streetview"
                        "wms_srs"       "EPSG:27700"
                END
        END
END

Output from terminal

mapadmin@mapserver:/etc$ sudo tilecache_seed.py "streetview" 04 09 -b "600000, 200000, 660000, 30000" -p 1 -f -c /etc/tilecache.cfg
Config file set to /etc/tilecache.cfg
###### (0, 0, 4), (16, -45, 4)
###### (0, 0, 5), (32, -90, 5)
###### (0, 0, 6), (64, -181, 6)
###### (0, 0, 7), (128, -362, 7)
###### (0, 0, 8), (256, -725, 8)
mapadmin@mapserver:/etc$

Any help on this would be great as it's really driving me nuts now, I've spent hours trying to work out why it's just not working.

Thanks


texts: QGIS 3.14 python environment path details

texts:
I can use the following python statements/commands to get information about the version of Python that QGIS 3.14 supports. I use these in QGIS built-in python console
from platform import python_version
print(python_version())

import sys
print(sys.version)
print(sys.version_info)

Is there a one-line command that will print the full path of the associated python interpreter to the python console?


texts:
Is there a step by step process to convert sets of raw satellite data to traditional GPS lat/long points or a website that takes the data and processes it?

Example of the raw satellite data:

$GPS30,180445.0811520511,2701.0000,N,09349.0000,W,20162.9,KM

Have looked thru the following:

https://www.quora.com/How-is-the-distance-between-a-GPS-device-and-a-GPS-satellite-calculated

https://www.courses.psu.edu/aersp/aersp055_r81/satellites/gps_details.html

https://www.researchgate.net/post/How_to_determine_the_latitude_and_longitude_of_a_target

What is the approximate error of the Pythagorean Theorem vs. Haversine Formula in measuring distances on a sphere at various scales?


texts: Best format for maps on mobile device with routing functionality

texts:
I am trying to choose the best file format for maps that meets these requirements:

There are command line tools to convert from .osm data
Are compact enough for mobile devices and internet download
Have the ability to be fed into a routing engine.

I am aware of .shp, geojson, spatialite and the proprietary ctm1. Any  other formats I should check out or opinions on the ones I mentioned?


texts:
Aplogoises if this has already been solved but I'm having problems using the Erase function in ArcGIS. I have had problems using the normal function, as it throws a Error9999 Topology error amongst others. So decided to Python! However having problems with invalid syntax, am I missing something obvious?

import arcpy
from arcpy import env

env.workspace = "K:\Head Offices\Conservation\Conservation Information Team\Systems Support\GIS\ArcGIS\Ancient Trees\Ancient trees\Comparisions\\"
arcpy.Erase_analysis('AncientTreesFullAugust2014 - Copy_font_point.shp','AncientTreesJuly2014TinyPolygon.shp','Aug2014AncientTreesDifferentToJuly2014.shp')

Many Thanks!


texts: How do I eliminate the black border on a georeferenced map layer?

texts: I have geo-referenced several scanned maps.  Theses are placed side by side on separate layers in QGIS. They overlay other older maps of the same areas. Georeferencing caused the maps to have black borders.  How can I change these black borders to transparent, or eliminate them, so that the underlying maps' data shows through the gaps in detail between the maps? Here is a screen shot:


texts: How to output parts of layers (shapefiles) that do not intersect using ModelBuilder?

texts:
I have two layers (shape files) that I want to select what do not intersect, to after all make a kernel of it.

How do I do that in ModelBuilder without scripting?

If someone can help me, even directing me to something to read, would be awesome.

I'm using ArcGIS 10.0


texts: In Leaflet how can I select and query objects inserted through WMS?


texts: Adding hover pop-up notes to map Arcmap desktop 10.3

texts: I have a layer of points defining a variety of geologic features overlying a global map.  I would like the user to be able to hover over a point and see a description of that feature.  Hyperlinks would be too complicated for this purpose.  Are hover-able map notes possible?


texts: Mapserver doesn't load geography columns of PostGIS

texts:
I have installed Mapserver 7.4.0 with PostGIS 2.4. However, I can't load any layer with geography column.
This is my MAP file (with contents prior to LAYER omitted):

MAP
<omitted>

  LAYER
    COMPOSITE
    END # COMPOSITE
    CONNECTION "host=127.0.0.1 dbname=testgis user=postgres password=****** port=5432"
    CONNECTIONTYPE POSTGIS
    DATA "geog from srwg"
    METADATA
      "coordsys_name"   "Longitude-Latitude / WGS 84"
    END # METADATA
    NAME "New Layer"
    PROJECTION
      "proj=longlat"
      "datum=WGS84"
      "no_defs"
    END # PROJECTION
    STATUS ON
    TEMPLATE "query"
    TILEITEM "location"
    TYPE POLYGON
    UNITS METERS
    CLASS
      NAME "Class (0)"
      STYLE
        COLOR 255 255 255
        OUTLINECOLOR 0 0 0
        SIZE 8
      END # STYLE
    END # CLASS
  END # LAYER

END # MAP

It comes with the following error:

msPostGISLayerWhichShapes(): Query error. Error executing query

Is Mapserver incompatible with geography columns?


texts:
I would like to add free hand drawings to my map. I tried the "Rectangles Ovals Digitizing" plugin but am looking for a free hand (not rectangle or circle) tool.
Also is there a plugin similar to the revision cloud in Autocad?


texts: 'Fix' offset and undersized data in QGIS

texts:
I'm currently working on a project to visualize some climate data, among the datasets I'm using is the data from the NCEP/NCAR Reanalysis Project.

Now, this data comes in a regular (non-gaussian) grid of a resolution of 144 by 73 and spans longitudes 0° to 357.5° East. This results in qgis displaying the following:

Where the colored data should span the entire globe but instead spans from 0°S to 73°S and from 0°E to 144°E

The data is in NetCDF (.nc) format

How do I go about 'fixing' this data to properly cover the real coordinates? I've tried georeferencing the file but QGIS is unable to write an output file (probably due to the multiple levels of data the file has).

PS: I'm working with the WGS 84 CRS


texts:
I have a task in QGIS (2.6), where I need to join two tables through an action (I think).

I have some projects (points) that I need to connect to a list of partners (also points). I have data in both PostGres and as simple files.
What I want is to be able to click on a project and then I will be able to get the partners highlighted/shown.

Is that at all possible in QGIS or would it be easier to do it in the database?


texts: Dynamic styling of data layer (icons) in Google maps api v3

texts:
I want to use different icons based on attibute values 'art' in a Google Maps data.layer. I've defined an customIcons object with all the styling options I need.

var customIcons = {
    Ap: {
        icon: './images/pin_green.png'
    },
    Bi: {
        icon: './images/pin_yellow.png'
    },
    Wa: {
        icon: './images/pin_brown.png'
    }
};

When I try to use this object in a style function, I get an error: "a.url.substr is not a function"

   map.data.setStyle( function(feature){
    var art = feature.getProperty('art');
    var icons = customIcons[art] || {};
      return  {
        icon: icons
      }
   });

When I use a single icon, passing the url like

icon: {url: './images/pin_green.png'}

it works, but all points use the same icon.
I've tried already a lot, but I cannot get the right syntax.


texts: Improving performance of ArcGIS Pro while working on a network?

texts: As many others, I'm working from home at the moment. ArcGIS Pro is running on my local machine with access to remote file servers through a VPN. VPN is at times running quite slow due to everyone working from home and thus every operation in ArcGIS Pro, like adding data, geoprocessing and exporting data, is quite slow. Are there any tricks to speed up ArcGIS Pro on a slow network? E.g. increasing cache size if possible? Using a local scratch gdb? I can't copy files over to a local database cause colleagues also have to be able to work on the same projects and with the same geodatabases.


texts: Reset leaflet routing machine route and controls

texts:
Im trying to build a geolocation based routing app in angular using leaflet.js and leaflet routing machine. I have this 'addRouting' function where I pass in a users location (fromLat, fromLng) and also a destination (toLat, toLng).

I am able to get an initial route to display but I am having some trouble clearing the map and controls so that I can pass in a new route and direction. With this current code the second route does not draw and I get a completely new set of controls displaying as seen below.

I think I need some way to clear and reset the map and routing functionality. Im new to using both leaflet and leaflet routing machine and I'm struggling to understand how this can be done.

  // Add Routing
  $scope.addRouting = function (fromLat, fromLng, toLat, toLng) {

    // Get map object
    leafletData.getMap().then(function(map) {

      // fit map
      map.fitBounds([[fromLat, fromLng], [toLat, toLng]]);

      // clear route and controls

      // add new routing
      L.Routing.control({
        waypoints: [
            L.latLng(fromLat, fromLng),
            L.latLng(toLat, toLng)
        ]
      }).addTo(map);

    });
  }


texts: Identify OSM road ids based on coordinates

texts:
I have a trace of GPS coordinates. I would like to get the OSM road ids of the roads that lie on the route defined by the coordinates.

I've used OSRM match service to match the coordinates to the road network. From the result I can get the individual node ids using annotations=true, but not the road ids. Should I somehow use the node id's to get the road ids, or is there some other way to achieve this?


texts: Fetch Google Map tile, without using Google Map API

texts: Does anyone here know is there any other way to fetch Google map tile, without have to use Google Map API? Microsoft Bing Map does provide Rest API. wonder if possible to with Google Map, Cheer.


texts:
If you had to teach someone the key stages to a typical GIS Analysis project, what would be the best generic answer?

I would like to see diagrams to illustrate this point.
Do not think it requires a long-winded answer.

I have been looking at Esri's answer.

This is the best I have found so far, but was wondering if we (community wiki) could do better.  I am thinking, perhaps a nice workflow diagram would be good.


texts: Layout Map Never Renders then Hangs if Map is Deleted

texts:
I have three layouts that are associated with my *.qgs project file.  Each layout includes at least one map and a number of text boxes that serve as captions for the map(s).

After a few days of formatting, my layouts are almost completely finished.  However, some of the maps on two of my layouts no longer display as I edit the layout (instead displaying "Rendering map" on a completely grey background).  For earlier versions of QGIS, the problem may have been that I toggled "Cache" or "Rectangle" instead of "Render," but these options do not display in this verions of QGIS (Girona, QGIS 3.0).

Importantly, if I try to delete any of the offending maps, QGIS hangs and I have to force quit or kill the program.  Also, I should mention that the offending maps successfully render when I export the layout to a pdf... I just can't see them while I'm editing the layouts.

Any ideas?

UPDATE: I upgraded to QGIS 3.8 (Zanznibar), and haven't had the problem since.


texts: ENVISAT ASAR .N1 file is not being opened by ERDAS IMAGINE 2011

texts: I am not able to open ENVISAT ASAR .N1 file in ERDAS IMAGINE 2011. The software has direct read option for files of this format. Whenever I try to open the file, software closes automatically giving an error message. Can anyone point out the problem and suggest solutions.


texts: How to resample QgsRasterLayer in QGIS 3?

texts:
I am generating png images of concentration maps, resulting from air quality modelling. Resulting files are croped and coverted to tiff files and than loaded into QGIS in Python:

rlayer = QgsRasterLayer(data_folder+parametr+'.tif',opis_txt)
projectInstance.addMapLayer(rlayer)

Then I load a pre-defiend QgsPrintoutLayout and export the results to a pdf file. Everything works fine, however by default raster is interpolated using Nearest Neighborhood which creates pixelized results.

In QGIS interface I can switch the resampling method for each layer to cubic or bilnear and this solves my problem, however I would like to do it automatically. So my question is can I do the same in Python script?


texts:
Problem: criteria for education is that it should be in 1 km buffer and have a population of 500. I want to identify which schools fulfill the criteria. I want to do analysis in ArcGIS.

Kindly suggest some tools or python script to evaluate which school are according to criteria.


texts: Enable users to read data from postgis-database using QGIS

texts:
I have uploaded a geojson file to a fresh Postgis installation with ogr2ogr following this example here.

I than created a new psql user for my colleague without any special rights but afterwards I granted him access rights to the db and all rights to all tables in public following the first answer in this question.

If I connect to the db in QGIS with the postgis connector and his credentials, I can see the table, however there is an error message telling me that I have to specify the data-type and the SRID. If I do so (data-type is multipolygon and SRID is 4326) I can import the table, however no single feature is shown.

If I connect to the db with my own user credentials that have all rights (SUPERUSER) I can import the table without any error, not even having to specify datatype and SRID. So the data is definitely okay.

I guess the problem is that granting all rights to all tables in public is not enough and somehow I also need to grant the rights to use the postgis extension which is in schema postgis or something like that. Can anybody give me a hint?


texts: Planetscope images atmospheric correction

texts:
I have downloaded an image which is level 3B processed (so I already have surface reflectance), but my assignment is to compare the data values of the SR file with my results.
At first I applied radiometric calibration in the AnalyticMS file and then tried to put the result in FLAASH but it didn't work.
From what I read, I realised that the AnalyticMS is already calibrated but it is not in a BIL/BIP format that FLAASH needs. So do I need to convert this file (.tif) in BIL/BIP format and then apply FLAASH? And if so, how do I do the conversion?


texts: Clipping Raster by value depending extent of another Raster

texts:
I have two Raster datasets in ArcGIS. Raster1 is a Digital Elevation Model, has z-values. Raster2 has the same extent, but contains a different parameter, h-values.

Now, what i want to do is cut/clip/extract the Raster2 to the extent of the DEM (Raster1) with z-values >= 5.67m or <=-5.67m only.

Up to now i used the following processing steps:

This workflow works (not yet automatically). However, i think it is not very effective. Especially when i want to repeat this step with several other masks (beside DEM). Do you know if there is a better way to achieve the same results?


texts: Google Maps API: Is there a way to do proximity analysis to POI

texts:
Using Google Maps API can I do proximity analysis, for example:

In a state, let's say Virginia, display all the points that are 500 ft/m from a POI such as McDonalds or Bob's Diner, 1,000 ft/m from a National Park and within 5 minutes driving from an interstate highway (Example I-95)


texts:
I want to be able to add a button into ArcGIS for my users, something like this:

http://gis.utah.gov/code-visual-basic/vba-link-from-arcmap-to-google-maps

Only, using VBA in ArcMap 10 now seems to be an issue, I can't find the UI control option anymore.

Any ideas?


texts: Finding intersection errors based on attribute value using ArcGIS Desktop

texts:
I have a road network table in a PostgreSQL database. The table has a level attribute which marks if a road is on the surface or if it is an under- or overpass. I would like to check the topology of this network and filter out the marked fictional (different level) intersections, and the not marked but real (same level) intersections. (Detailed in pictures below.)
Now I know that I can do this in PostgreSQL, but can it be done in ArcGIS Desktop?
So far for topology checks I never needed this kind of rule, and I cannot find an option to make a topology rule based on an attribute value. Currently I don't have acces to ArcGIS Data Reviewer, but maybe that could solve my problem.
The illustration of my problem:

The colours and the numbers represent the level of the road. I would like to find the following errors:

Either two roads with the same level value intersect each other but don't have an intersection point
or they do have an intersection point, but shouldn't, because they don't have the same level value.


texts: How to dissolve based on the overlap of polygons in the input file?

texts:
I am using ArcGIS 9.3/10 to dissolve few hundreds of overlapping polygon features.  Now, I am seeing that Arcgis is not able to do dissolve for  5000 polygons.   Generally, I used to dissolve (unchecked create multipart features)  in arcgis based on geometry not with any dissolve fields.

I am trying with QGIS version -1.8.0-Lisboa  dissolve tool for that 5000 polygons, here it is mandatory to select any one of the dissolve field.  note: there is no common field to group the polygons.  I selected dissolve, but it generated ONE polygon (with multiparts)..

I need multiple dissolved polygons based on the overlap of the polygons in the input file.

How to do this in QGIS or any other open source available, (since arcgis is not able to do)


texts: gdalwarp - merge two images, but only the no-data values

texts: I am preparing tiff elevation files. For one particular country I have a 10 meter elevation model, but the data is present only for the specific country - so when the image is sliced into smaller parts - for example 0.1 x 0.1 degree - there are null (no data) values outside the country's border. I have figured out that I can use gdalwarp -r bilinear 10M_tiff.tiff 30M_tiff.tiff out.tiff file to merge 10M and 30M tiff. But this command merges files fully. Is it possible to add additional parameters to the gdalwarp command so it will add values from 30M tiff only in the case that data in the 10M tiff is missing? (I would like to preserve original 10m elevation data where possible)


texts:
I've been unsuccessfully trying to install QGIS using Homebrew (used Homebrew to install GDAL and GSL) as outlined here

My OS is Mac Yosemite, 10.10.5.
The installation sort of finishes, but with a warning

  Warning: The post-install step did not complete successfully
  You can try again using brew post install osgeo/osgeo4mac/qgis-26

The app does not start due to lack of compatibility with MacOX system.

I also tried to use the .dmg from http://www.kyngchaos.com, but it does not even open the image complaining that GDAL 1.11 is not installed, when in fact it is.

Any tips, please?

UPDATE

I tried with qgis28 and still get the following warning during installation:

==> Pouring qgis-28-2.8.3.yosemite.bottle.tar.gz

==> defaults delete "/usr/local/Cellar/qgis-28/2.8.3/QGIS.app/Contents/Info.plist" LSEnvironment

==> defaults write "/usr/local/Cellar/qgis-28/2.8.3/QGIS.app/Contents/Info.plist" LSEnvironment "{ 'PATH' = 'home/.rbenv/s
Last 15 lines from home/Library/Logs/Homebrew/qgis-28/02.osgPlugins-3.4.0';:

Warning: The post-install step did not complete successfully
You can try again using `brew postinstall osgeo/osgeo4mac/qgis-28`
*(which upon running returns the very same warning)*

defaults write "/usr/local/Cellar/qgis-28/2.8.3/QGIS.app/Contents/Info.plist"
LSEnvironment "{ 'PATH' = '(my paths) 'PYTHONPATH' = '/usr/local/Cellar/qgis-28/2.8.3/lib/python2.7/site-packages:/usr/local/lib/python2.7/site-packages'; 'GDAL_DRIVER_PATH' = '/usr/local/lib/gdalplugins'; 'GRASS_PREFIX' = '/usr/local/opt/grass-64/grass-6.4.4'; 'OSG_LIBRARY_PATH' = '/usr/local/lib/osgPlugins-3.4.0'; }"

Could not parse: { 'PATH' = '(my paths)' } Try single-quoting it.

upon starting qgis

Warning: loading of qgis translation failed [/usr/local/Cellar/qgis-28/2.8.3/QGIS.app/Contents/MacOS/../Resources/i18n//qgis_en_US]

Warning: loading of qt translation failed [/usr/local/Cellar/qt/4.8.7_2/translations/qt_en_US]

Warning: QGraphicsScene::addItem: item has already been added to this scene
ERROR 1: dlopen(/usr/local/lib/gdalplugins/gdal_GRASS.so, 1): Library not loaded: /usr/local/lib/libgeos-3.4.2.dylib
  Referenced from: /usr/local/opt/grass-64/grass-6.4.4/lib/libgrass_vect.6.4.4.dylib
  Reason: image not found

ERROR 1: dlopen(/usr/local/lib/gdalplugins/ogr_GRASS.so, 1): Library not loaded: /usr/local/lib/libgeos-3.4.2.dylib
  Referenced from: /usr/local/opt/grass-64/grass-6.4.4/lib/libgrass_vect.6.4.4.dylib
  Reason: image not found

I have libgeos-3.5.0.dylib, not libgeos-3.4.2.dylib. Where could I change version referencing?
I have Python2.7 as the system default version and miniconda's Python3.

I did notice confusions between Python versions and GDAL. Unfortunately, have not been able to figure it out yet. When I do brew link gdal, it links to Python2.7 and can't use it with IPython3 (obviously...), but when I unlink it, the command line tools (ogr2ogr) does not work.

What am I missing and how to fix the geo-toolkit (GDAL+QGIS working together in peace)?


texts: Newly added points disappearing after saving edits in QGIS.

texts: I am adding features to a shapefile point layer in QGIS 2.12 Lyon.  When I add the new point I can see it, but once I click the Save Edits button it disappears.  When I click Toggle Editing button to end my editing session it remains not visible.  The point appears in my attribute table but it is not symbolized on the map.  I am not using categories to symbolize the layer and the coordinate system matches that of my QGIS project.  Why are my new points not being rendered?


texts: Feedback from a QGIS map posted on a web page

texts:
I have QGIS version 3.4.2-Madeira and I'm still a beginner with this software.

I have created a web mapping service that actually is hosted by a QGIS server. In order to do this, I've used the Qgis2web plugin and I'm feeling confident with it now. First I've created some CSV files with points coordinates and other features in them and then I've loaded these files as a delimited text layer.

What I want to do now, is to add something that allow me to have a feedback from the map. In other words, when a point on the map is clicked, I want to trigger a Python script that can receive and elaborate the feature related to the clicked point.

I've tried to give a look at the actions provided by the properties tool, but it seems that these actions cannot be exported with qgis2web.


texts:
I am trying to write a python script to batch Aggregate a bunch of different rasters. I get a Parsing Error Syntax error for line 11.

# Batch Aggregate raster tool
import arcpy
from arcpy import env
from arcpy.sa import *

env.workspace = r"C:\rasters"
out_workspace = r"C:\rasters\agg"

rasters = arcpy.ListRasters()

for raster in rasters
    outAggreg = Aggregate(raster, 10, "MEAN")
    outAggreg.save(out_workspace, raster + "_agg")


texts: I have plotted 30,000+ points in QGIS by postcode, various data items for each. How do I resize these plots based on the activity at each of these points i.e. small dot for <100, larger dot for 100-200 and larger dot for 200+?


texts: Statistics of two point features between a line feature

texts:
I'm using arcgis. My datasets are as follows:

point features

values of passed cars in a specific time

line features as segments between the points

overall it is a street network with stops.

My aim:
I want to add to the line feature attribute table the information of which point features are on each end of the line. Additionally calculating the difference of passing cars between the points.

Can you give me a hint how to do this?

EDIT: Sample Picture


texts: New field names after joining 2 tables in QGIS

texts: When joining two files (A.csv and B.shp with a common unique ID) in QGIS the new fields in B.shp (from A.txt) include the name of the field + the name of the file where it comes from (A). For example if we import the field "gender" it will appear in b.shp as A_gender not gender only. Now, the problem comes when the field name es very long because when you save the new joined file (B + A) as a .shp, because it only allows field names with a maximum of 10 characters, the field name is truncated. Any solutions?


texts: Trouble accessing Sketchup Features to SKP Toolbar in ArcMap 9.3?

texts: I am having trouble getting the Sketchup plugin to work in 9.3. I have installed plugin into the correct location, been able to locate the proper .dll, but when I add it, and scroll down to where it should be, it doesn't appear. Does anyone know how to get this to work? Thanks.


texts: Densifying OpenStreetMap (OSM) network nodes?

texts:
I am working with osmconverter to convert osm files(*.osm) to *.pbf, then i use osm2po to get sql file that run into PostGis to get a network table.

The last step is to run a createTopology statement in SQL PostGis Editor to get the vertices of network.

However, this proccess only creates the initial and final nodes of a network stretch intersection and i would like to add more nodes between initial and final ones.

Editing the osm2po.config file of osm2po could be a posibility?


texts: Fastest way to test if raster contains data within a polygonal area

texts:
I am writing a python script for a geoprocessing tool in arcmap.  I have a polygon in WGS 1984 Web Mercator (Auxiliary Sphere) and a raster grid, raster1, in WGS 1984.  I reproject the polygon to  create a mesh of points that are contained within the boundary of the polygon and laid out in a uniform grid.  Now, the goal is to check raster1 at each point in the mesh and detrimine if the corrosponding cell has a value at that xy.  If it does remove the point from the mesh.  If it doesn't, keep the point.  In the end I want to have a fragment of the mesh of points which contains all points for which the raster had no value.

My first attempt was to loop through the points and use arcpy.GetCellValue_management() to see what the value was at each point.  But the GetCellValue_management fuction seems to take a painfully slow 2-3 seconds (I have a lot of points).  Anyone know why this takes so long?  An identify on the same raster in arcmap is almost instant!

So now I'm thinking about using Clip_management to clip out the intersection of the polygon and the raster and then RasterToPolygon to get a polygon representing that intersection.  Then finally using Erase_analysis to erase from the point mesh those points in the intersection.

What do you guys think?  Is plan two good?  Whats the fastest way of doing this?


texts: QGIS manually select overlapping features/data points

texts:
I am trying to manually  select features visualized on a map to change an attribute of several features at once by highlighting them on the map using the "select features tool".

I'm using the multi edit toggle so that I can modify field data for all selected features at attribute table. The problem is that there are so many data points/features that are in the same location or close proximity that I cannot verify each point is selected, and it appears that features that are not visible are not being selected/the attribute change is not applied.

How can I select (and deselect) manually all features in the geographic area that I am selecting? Essentially, I am trying to clip manually.


texts: Error with CMV Print tool when operational layers are turned on

texts: I am new to JavaScript and have used the CMV to jump start my first application. I am getting an error on the print tool when I have any of my operational layers turned on; print works find with Esri basemap data only.  I am sure that I am just missing something in my configuration.


texts: Using Arcpy.UpdateCursor to delete adjacency rows based on a group ID

texts:
I have this sample file shown in the picture 1 below. it is a sample data set of a phone survey of drivers. I am trying to find out when those drivers started to drive.

My main goal is to build a loop to go through the rows and compare each row for each unique trip id and to check between those rows when the X (dbX field) and the Y (dbY field) have changed.
In my example (Picture 1) I have only two unique id trips - 55,56 but in my main data set i have alot more:

This is what I am trying to achieve in my goal data set:

First row in goal data set (see picture two) will be based on:
For example in picture 1 - the X and Y values in the first row changes from OBJECTID =6, when those values change I want to delete all previous rows until row 5.

You can see an example of what I am trying to accomplish in picture 2.
Next values Until last rows -
For this values, I want to keep the first row where X and Y values changed and   delete all values of the same X and Y untill the last row before the next X,Y changes again.
to make this step clear I want to keep only rows with OBJECTID = 6 AND 13 and (picture 2)

Keep in my mind there are some Unique rows that Won't have more rows with the same X and Y  like the row with OBJECTID = 78.

Last row - at end of each unique id I want to keep only the first row that is diffrent from the previous row in terms of x and Y :
for example in picture 1 I want to keep only OBJECTID  = 149 and delete OBJECTID =1 150 AND 151

Initial Data set picture 1:

This is the code I started writing but I think I am not on the right track

fcVertex ="Copy_Points_with_id_north_to_center_sample_55_57_copy"
fieldsvertex = ["dbX","dbY","Trip_ID","TimeStamp"]

with arcpy.da.UpdateCursor(fcVertex,fieldsvertex,sql_clause=(None, 'ORDER BY Trip_ID ASC ; ORDER BY TimeStamp ASC')) as deleteCursorfixtime:
for row1 in deleteCursorfixtime:
    for row2 in deleteCursorfixtime:
        if row1[2] == row2[2]:
            if row1[0]== row2[0] and row1[1] == row2[1]:
                 if row1[3] != row2[3]:
                     deleteCursorfixtime.deleteRow()

Goal Data set picture 2:


texts: Difficulty when working in QGIS with ArcGIS Map Server Layer

texts:
I need to perform a point in polygon analysis in QGIS on parcel data from an Ohio Department Resources MapServer:
https://gis.ohiodnr.gov/arcgis_site2/rest/services/OIT_Services/odnr_landbase_v2/MapServer

The parcel layer will load as a MapServer layer, but fails when trying to load it as a Feature Server layer. The other layers from the server will load as a FeatureServer layer. This is the error I get when trying to load it as a feature server:

Layer is not valid : The layer crs='EPSG:3857' filter='' url='https://gis.ohiodnr.gov/arcgis_site2/rest/services/OIT_Services/odnr_landbase_v2/MapServer/4' table="" sql= is not a valid layer and can not be added to the map. Reason: AFSProvider getObjectIds failed: Network error - Operation canceled

Loaded as MapServer layer, I can use the identify features tool to view the attributes of each parcel individually. However, whenever I attempt to perform any functions with the raster, I get the following error:

ERROR 4: ` crs='EPSG:3857' format='PNG32' layer='4' url='https://gis.ohiodnr.gov/arcgis_site2/rest/services/OIT_Services/odnr_landbase_v2/MapServer' table="" sql='
does not exist in the file system, and is not recognized as a supported dataset name.

Ideally, I'd like to convert the raster to vector then use it in a point in polygon analysis. Any ideas?


texts: OpenLayers and proj4js.defs() - why does one custom projection work and not the other?

texts:
The javascript at  https://jsfiddle.net/nsands/kvhcuL72/ is the simplest demonstration I've come up with for this issue.  It is based on OpenLayers example code, but I've defined the map projection using proj4js.

It works fine for my custom EPSG:28355 projection, but it does not work for my custom EPSG:4326 projection, which results in an empty map.  The projection is correct according to https://epsg.io/4326.

Below are the two proj4.defs() lines from the jsfiddle.

This first one works fine and OpenLayers reprojects (warps) the OSM map (EPSG:3857) to EPSG:28355 no problems:

//  EPSG:28355
proj4.defs('BLAH', '+proj=utm +zone=55 +south +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs');

(It does take a little time for the map to appear, as warping rasters is not a super-fast process.)

This second one does not work and results in an empty white map:

//  EPSG:4326
proj4.defs('BLAH', '+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs');

If I use the already built-in EPSG:4326, instead of my own custom defined one, it also works just fine and reprojects the map perfectly.  In the jsfiddle, this can be tested by changing which of the projection: lines is uncommented in the map's view definition.

Why does my custom definition of EPSG:4326 not work in my OpenLayers code, even though the built in EPSG:4326 and my custom EPSG:28355 both work fine?

I assume I'm using the libraries incorrectly, or perhaps assuming functionality that does not exist.  But from the documentation I've seen, I had expected it to work.

(I'm using a custom definition of EPSG:4326 because in my real OpenLayers app, the projection is determined at run-time and the EPSG code may not be available, even then - only the proj4 string.  Therefore I cannot hard-code the projection in the javascript, and I need to be able to work without an EPSG code.  It needs to work for whatever projection is passed in, including the proj4 string for EPSG:4326.)

UPDATE - Documentation:

I had been under the impression that OpenLayers could simply use proj4js defined projections.  Although the OL documentation is not entirely clear on this, I had got this impression from several 3rd party examples, from the snippets of OpenLayers documentation below, AND because it appears to work fine in my JSFiddle linked in the first line of this post above.

From the OpenLayers Example's comments in the code at https://openlayers.org/en/latest/examples/wms-image-custom-proj.html :

  If you use Proj4js only to transform coordinates, you don't even need to create an ol.proj.Projection instance. ol.proj.get() will take care of it internally.

From the OpenLayers API documentation at https://openlayers.org/en/latest/apidoc/ol.proj.html :

  [OpenLayers] will check if the Proj4js library and the necessary definition are loaded; if so, it will register the appropriate ol.proj.Projection object and add transform functions between the new projection and all the existing ones.

From the OpenLayers API documentation at https://openlayers.org/en/latest/apidoc/ol.proj.Projection.html :

  You can use [ol.proj.Projections] in applications, but this is not required, as API params and options use ol.ProjectionLike which means the simple string code will suffice.  ...  If you use proj4js, aliases can be added using proj4.defs()


texts: Numbering adjacent points/centroids in sequential order - QGIS 3.18

texts:
I have, for example, this layer with points or centroids (with x, y coordinates)

I want to enumerate the points from right to left (for example) and top to bottom like this:

I tried sorting them using the Sort and Number plugin (using X and Y), I got close but not enough
I even tried to follow and modify the below

Automatically numbering points East-West & North-south on QGIS?

but still didn't get far
Is there any other way?


texts:
I have a KMZ vector file which works fine on my Google Earth application, but I want to overlay this on my phone (android) through Google Maps.

Is that possible?


texts: Updating geometry of point using OGR in Python?

texts:
I need to change the coordinates (geometry) of some points in a shapefile. I can't find the good method.

if ( zone[best_y, best_x] >= ( nb_pixel_area - toler) ) and ( zone[best_y, best_x] <= ( nb_pixel_area + toler) ):
        print('======= station deplacee')
        new_x = (( pix_x + best_x ) * hres ) + georef[0]
        new_y = (( pix_y + best_y ) * abs(hres) ) + georef[3]
        wkt   = "POINT(%f %f)" %  (new_x , new_y)
        point = ogr.CreateGeometryFromWkt(wkt)
        gauge.SetGeometryDirectly(point)

I was also not able to use the setX() and setY().

Has someone already done that action?


texts: Create a line & label from centroid to edge of circle with Geometry Generator?

texts:
I'm looking to create a line from centroid of a circle and label it with the radius using the geometry generator but don't know where to start. QGIS 2.18.15.
I'm using the Ovals, Rectangles plugin to draw the circle.


texts:
I was trying to install Postgres several times, but it didn't work out.
I am using Mac and I tried to install Postgress.app, I got problems with database connection.
I decided to install Postgress using HomeBrew.

At the beginning, I uninstalled all the versions:
Using brew remove --force postgresql to remove all versions

I used
brew cleanup posgtres as well

Then, launched the installation using home brew

> ==> Downloading https://downloads.sf.net/project/machomebrew/Bottles/postgresql-
> Already downloaded:
> /Library/Caches/Homebrew/postgresql-9.3.2.mountain_lion.bottle.tar.gz
> ==> Pouring postgresql-9.3.2.mountain_lion.bottle.tar.gz
> ==> Caveats If builds of PostgreSQL 9 are failing and you have version 8.x installed, you may need to remove the previous version first. See:   https://github.com/Homebrew/homebrew/issues/issue/2510
>
> To migrate existing data from a previous major version (pre-9.3) of
> PostgreSQL, see:
> http://www.postgresql.org/docs/9.3/static/upgrading.html
>
> When installing the postgres gem, including ARCHFLAGS is recommended:
> ARCHFLAGS="-arch x86_64" gem install pg
>
> To install gems without sudo, see the Homebrew wiki.
>
> To reload postgresql after an upgrade:
>     launchctl unload ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist
>     launchctl load ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist

Any recommendation to install Postgres right way on my machine.


texts:
While viewing 3D buildings in ArcScene, a flickering error(refer screenshot below) can be seen visually due to the Non planar surface. The options I have checked are Topology in ArcGIS & QGIS, Geometry checker in QGIS, but it does not find the errors.

It would be better if someone provides solution to find the error in any free softwares/Tools


texts: Performing If Statement in Python Parser of ArcGIS Field Calculator?

texts:
I've one field "MAXSPEED". I want a Field Calculation that will calculate an additional field ("noise"):

If MAXSPEED > 40 then the term: (73.5 + Log ( 25 ) * ( [MAXSPEED] / 50)) should be used to calculate "noise"
but if MAXSPEED < 40 then "noise" should be 71,1

I have no programming experiences. Python or VB, both works for me.

Edit:
sl = maxspeed

I figured out the term wasn't alright.
This is the right one 73.5 + 25log(sl/50)

import math
def test(sl):
 if sl>=40:
  result = 73.5 + (25*(math.log(sl/50.0))
 elif 30<=sl<40:
  result = 71.1
 else:
  result = 0
 return result

The result for sl = 50 is alright (73.5) but all values >50 are wrong:
sl(60) = 78.06 instead of 75.47
sl(70) = 81,91 instead of 77.15


texts: Best way to combine 7 different shapefiles into one geodatabase

texts: I have 7 different point shapefiles, and want to join them into one geodatabase. What would be the best method to do this in ArcGIS10?


texts:
My findTask is from the SAMPLE on Esri's website

http://help.arcgis.com/en/webapi/javascript/arcgis/help/jssamples/find_map_datagrid.html

I have incorporated into the project I am working on. I've looked over the code again and again and can't seem to figure out why this is not working.

Here is a link to the map.. http://www.co.frederick.va.us/planning/newmap1copy2.html


texts: Select points within a relative number range

texts:
I need to select points that have attributes that are within a relative number range of each other. For instance; given the following numbers: 95,705,139,65,537,266,525 and 188; I need to find all of those numbers that are within a range of 50, 100 and 150 of each other.
I then need to find those that are within a distance of each other.
I am using QGIS. Any ideas gratfully accepted. Thanks.


texts: Notepad++ syntax highlighting support for .mapfiles?

texts:
I was looking for a language definition for mapserver ".map" files in Notepad++ but could not find anything.

Is there anyone who can recommend / has such a file? an already defined one?

If not, is there an open source text editor that can highlight .map file code for easy ready in windows?

I searched the web for such editors but no luck yet.


texts: Exporting data from a WFS service to csv file using qgis

texts:
I have a service that contains a list of points with some meta data and I would like to export this to a csv file. I remember doing this some months ago and it worked well, but now I can't find the method (or plugin?) that I used.

Has anyone done something similar and know how to export data from a WFS service to a CSV file using QGIS?


texts: Checking the registration accuracy of already-orthorectified images

texts:
I acquired several Landsat 5-8 images corrected at Level 1T. I also have aerial ortophotos of the same area. From a visual assessment the co-registration between the images seems good, but I need to quantify the registration accuracy. My approach is to simply find some Check Points and calculate the average RMSE, but which transformation type should I choose to compute the residuals? In the Landsat product specifications and user handbooks I can't seem to find specific info about what they use.
(I am using QGis 2.10)


texts: How to overlay Image to openstreetmap using leaflet.js

texts:
I want to overlay a wide range satellite image onto openstreetmap using leaflet.js. The satellite image is in Equidistant Cylindrical Projection.

This is how I initiate the layer.

L.imageOverlay(imgUrl, [[-15, 75], [45, 145]], {opacity: 0.6, autoZIndex: true});

The overlay result is attached below. As you can see, the coastline of the satellite image (in purple color) is not aligned with that of openstreetmap. Is that something wrong with the image or map projection? or I should use other way to overlay the satellite to map ?


texts: Removing images based on band threshold using Google Earth Engine?

texts:
I am using GEE and wish to set a threshold and exclude images based on an the image's band value and remove it from a collection.  I do not want to mask the image, I want it physically out of the collection.  As far as I can tell using ee.filter only works with metadata, not the images' bands.

Anyone have a clue?


texts: Why can't save changes on GeoServer layers via QGIS?

texts:
I am using QGIS 2.14 on Windows 10, and GeoServer 2.8.3 on Windows 2008 Server (VPS).

QGIS manages my GeoServer layers with Web Feature Service. I would like to change the geometry or attributes of the layers stored in GeoServer with QGIS, but I can't. The added points appear on the web map, but I can't delete or modify these points and don't know why. No errors reported, seems like the changes have been saved. Furthermore I can't draw new lines and polygons: in the attribute panel the data appears, but it has no geometry so I can't visualize it.

Where's the problem?


texts: Group and chop vector layer by attributes

texts:
Im new to QGIS but i have a layer which contains buildings.
What i want to do is to chop up that layer into groups of buildings.
So if you imagine a town with 5000 buildings, i want to create new layers each containing 50 buildings only.
I can extract attributes, but dont know how to iterate over the entire layer pulling out buildings 50 at a time to create effectively a grid or polygon with 50 houses each time.
Help :)


texts: How to split polygon into equal segments in QGIS?

texts:
I try to split polygon layer into equal length segments of 1000m:

The attribute table of the layer is:

I have read those links but didn't find a solution to my question:

How to split a vector in equal smaller parts in QGIS or similar?

How to split an irregular polygon into equal areas?

I also tried to use "split vector layer" function but didn't get desirable answer.

I also tried to find the "Polygon Splitter" (in this link polygon split with predefined area) plugin but I didn't find it in the Plugin list.


texts: How to find distances between countries based on borders in R?

texts:
I'm trying to get the distances from one country to a list of other countries based on the countries border in R.
I was able to find one example: Closest distance between countries but it is using the package "maps" which doesn't seem to work anymore.
library(maps)
library(geosphere)
library(dplyr)

world.map <- map(database = "world", fill = TRUE)

Resulting error:
Error in as_mapper(.f, ...) : argument ".f" is missing, with no default
Also, I was able to find the package cepiigeodist but that package calculates distances based on city not borders.
Do you know of another package I could use or how I could fix the code to work?


texts: Convert UTM northing and longitude to latitude

texts:
I am doing some work with the Military Grid Reference System (MGRS), which is based on Universal Transverse Mercator (UTM).

I find that I need to convert from UTM northing and longitude (actually, delta angle between desired longitude and appropriate UTM central meridian) to latitude. I've searched for days and cannot find this conversion.

I need an algorithm. Can anyone point me to a reference to such an algorithm, or to open source software that does this conversion?


texts: Why is points to path tool connecting the start and ending points?

texts: The PointsToPath tool is connecting the start point to the end point.  I'm new to QGIS. I'm using an older version - 3.4.5. I have manually entered in the points in as a scratch layer. I export as a shapefile. Points to path tool connects the dots but it is also connecting the start and end dots. I don't want it to do that.


texts: Calculating distance while adjusting for obstacles in ArcGIS Desktop?

texts:
I have a global grid of points in the ocean and need to calculate the distance to and identify the closest 10 polygons along the coastline for the entire world while also avoiding crossing land.

For example, in the Figure below, the circled point would not include the green line distance. Instead the distance would consider going around the peninsula.

Near table produces the type of output I need but calculates distances without consideration for whether the path crosses land.

I also tried cost distance by creating a raster of the land at high cost and ocean area at low but if my understanding is correct, that type of analysis is limited to between just two points and the output isn't distance, it is a distance raster.

I have roughly 40,000 ocean points and polygons buffered around 1 degree of coastline. I need to find the 10 closest polygons for each point.


texts: Shapefile uploaded to GeoServer via REST API doesn't get published

texts:
I'm using PHP's cURL to upload Shapefiles to my GeoServer. It works fine but, sometimes, some of the Shapefiles got correctly uploaded but they aren't published automatically. Other times they do (thats what I want).

If I try to manually publish one layer uploaded this way I got two errors:

I see in the config that my native SRS shows as UNKNOWN and the declared SRS is empty (I'm sorry for the screenshot, my GeoServer is automatically configured in Catalan and I can't set the language to English):

I guess the problem comes from the .PRJ file in my Shapefile, but I don't know if that's true and if there's really an error there...

A sample .PRJ on my files:

PROJCS[
    "ETRS89_UTM_zone_31N",
    GEOGCS[
        "GCS_ETRS_1989",
        DATUM[
            "D_ETRS_1989",
            SPHEROID["GRS_1980",6378137,298.257222101]
        ],
        PRIMEM["Greenwich",0],
        UNIT["Degree",0.017453292519943295]
    ],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",0],
    PARAMETER["central_meridian",3],
    PARAMETER["scale_factor",0.9996],
    PARAMETER["false_easting",500000],
    PARAMETER["false_northing",0],
    UNIT["Meter",1]
]

My correct SRS should be EPSG:3043 (or the equivalent EPSG:25831). Is there something wrong with my .PRJ?

UPDATE

After Andrea's answer, all of my uploaded Shapefiles get the correct SRS but in some cases they aren't still published due to the Field 'latLonBoundingBox' is required error. So,

Is there a way to force the calculation of the BoundingBox at upload time (best option) or after upload with another API call (not that good...)?


texts: Keep the same field headers after joining a table to a shapefile in QGIS

texts:
I noticed that after joining a table to a shapefile the headers of each fields in the table used for the join are changed by QGIS and they are attributed to a different name.

For instance, I had a shapefile with vegetation_codes and a table with vegetation_codes and veg_definition (these were the headers). After joining the table to the shapefile and also saving the shapefile and creating a new one, the vegetation_classes header was changed into vegetati_1.

Is there a way to keep the original headers?

I am using QGIS Dufour on Windows 7 and the table that I join to the shapefile is CSV (tried with dbf as well and the problem is the same).


texts: Using a list of geographic locations, and determining the X closest locations to a user-defined location

texts:
I've got a list of geographical locations in an Excel spreadsheet.  I want users to be able to search for a user-defined location, and then have the X number of closest locations from the list pulled up and displayed, sorted by nearest to farthest by travel time via car.  I know Excel alone obviously can't do this.

I have minimal/no programming knowledge.  Just an Excel tinkerer.  I figure that, at a minimum, this would require utilization of a mapping service like Google Maps or Mapquest.


texts: How to connect to a specific database with SQL Server in QGIS

texts:
I have the credentials to access the SQL Server database for the company I work. However, the user credentials it was provided to me only have the permission to access 1 specific database, called let's say: database_name_1
When I click in "List Databases" it says I have no permission to access the 'master' of the server and gives me an issue:  'QODBC3: Unable to connect'.
So, where could I specify it in QGIS for access only the database_name_1?


texts: Why difference in delineation of watershed by two online watershed modeling tools?

texts:
I am using two online watershed delineation tools- eRAMs and Model My Watershed (MMW)- to auto delineate watersheds using water quality monitoring sondes as my outlet points.   I have three pieces of equipment on different streams so I have three different outlet locations. Two out of three outlets/sondes have similar watershed delineations, but one sonde location has dramatically different watershed delineations.  Here is pic of sonde location, the green marker is our coordinates and the red circles are different outlet locations I've manually added in eRAMs tool:

Even after trying multiple outlet locations between the bridge and the streams confluence with another stream, as well as even trying locations upstream of the bridge, the tools result in the same watershed delineations shown below:

Note: eRAMS result is green boundary, MMW result is orange boundary, Creek where sonde is located is highlighted in red.

I lean toward the MMW delineation, as the delineation encompasses the creek on which the sonde is located. Note that these tools move the manually placed outlet points to nearest downstream NHD cell, but even the moved outlets are above the confluence.

What might be the reason these tools have such different delineations?

I believe that both tools delineate based on 30 x 30 m DEMs and the NHDPlusV2 Medium Resolution stream network.   eRAMs uses TauDEM tools/algorithms found here: https://erams.com/documentation/watershed-delineation-tools/
It's difficult for me to interpret the subprocesses of MMW's Rapid Watershed Delineation algorithms listed on GitHub (limited development background), but I think they are modified versions of TauDEM algorithms, similar to eRAMs.


texts: Fastest Way to Intersect Envelope with Multiple Feature Classes ArcObjects

texts:
I have the situation where I am doing a large number of intersections and I need to do them fast. The situation is I have a iMap with 1 or more layers and a series of envelopes, lots of envelopes. I have tried the following:

        long nFeatureCount;
        iExtent->PutCoords(ulX, ulY, lrX, lrY);
        // I created an array of all the layers feature classes at the outset
        for(int i=0; i<nFeatureClassCount; i++)
        {
            iSpatialFilter->putref_Geometry(iExtent);

            iFeatureClasses[i]->FeatureCount(iSpatialFilter, &nFeatureCount);

            if(nFeatureCount > 0)
            {
                return true; //we have an intersection
            }

        }

I also tried doing a select at the map level like so:

        long nFeatureCount;
        iExtent->PutCoords(ulX, ulY, lrX, lrY);
        ipMap->ClearSelection();
        ipMap->SelectByShape(iExtent, NULL, VARIANT_TRUE);
        ipMap->get_SelectionCount(&nFeatureCount);

        if(nFeatureCount == 0)
        {
            return false;
        }
        else
        {
            return true;
        }

Both of these work and the iMap seems to be a bit faster when I have 5 or so layers. I was just thinking someone had encountered this and might have a faster way. I saw someone had the idea of throwing all the geometries in a IGeometryBag but wouldn't that negate the spatial indexing?


texts: How detailed should I make the shapes.txt for a General Transit Feed?

texts:
I am working on creating a transit feed with General Transit Feed Specifications in mind. I'm torn into how detailed the routes should be for the shapes.txt. Do I map just when the bus is on the main road? Or should I show what parking lot entrance it uses or how it turns around at the end of the road?

Is this all preference and I'm just being too obsessive?

Here's a picture of when I took the bus route off the main road to show how it reaches the bus stop. Is this necessary?


texts: Will mousedown events fire with Touch events on OpenLayers mobile?

texts:
I can't get the mousedown event to fire on a mobile device when I click on a marker. I'm using openlayers 2.11 with TouchNavigation. The mousedown event fires just fine in Chrome on my Desktop. Are there touch specific events for openlayers? If yes, where can Ifind the list. The openlayers documentation is driving me crazy.

The code I use:

  var start_point = new OpenLayers.LonLat(latlngs[0].x,latlngs[0].y);
  var start_marker = new OpenLayers.Marker(start_point,green_pin);
  start_marker.events.register('mousedown', start_marker, function(evt) { alert('Ok'); OpenLayers.Event.stop(evt); });
  StartFinishLayer.addMarker(start_marker);


texts: Clipping features depending upon percent coverage by other features

texts:
I have a shapefile composed of several thousand square polygons of equal size, arranged in a grid. I have another shapefile with a few dozen circles. The squares are about 1/10th the size of the circles.

I would like to clip the squares using the circles so that if the square is less than halfway inside any one of the circles then it gets left out. If a square is 10% inside one circle and 70% inside another circle it should only be included in the one where it is 70% inside. Some squares will wind up in multiple circles.

I'd like to clip the shapefile with the squares by the one with the circles, but if a square is less than halfway inside a circle then it should be left out completely - just blank space.


texts: How to prevent ArcGIS Pro Arcade expression adding one month on to my desired date?

texts:
I am trying to add dates to two date fields in ArcGIS Pro using expressions in Arcade.
When I use the expression Date(2020,10,29) the result in the field is 29/11/2020, which is one month later than my desired date. The same thing has happened in the next field for a different date which should be 01/01/1983 but is resulting in 01/02/1983:

Does anyone know why this is happening and how to prevent it?


texts: Attaching pictures to polygons in attribute table in batch using ArcGIS for Desktop?

texts:
I use ArcGIS and I want to attach a picture of each polygon as raster in attribute table and I have 1900 of polygons.

Can somehow attach batch photos as raster that have same ID like polygons? It is possible?

I can do it one at a time.


texts: I am trying to open shp2pgsql.exe to import shapefile to PostgreSQL. But something happens because shp2pgsql never displays an opening window. For a very little time it seems it will open a window. Unfortunately  this window suddenly disappears. It never gets opened. I'm using Windows 10,  PostgreSQL 10, pgAdmin 2.1. I have just downloaded PostgreSQL and PostGIS this is the first time I'm using them.


texts: GetFeatureInfo for multiple layers in OpenLayers 4

texts:
I have four WMS layers however, only the first layer loaded is identifying.

I have loaded the layers individually and have the layer-switcher to enable individual layer switching, can someone advise on how to get the second code to work?

Single layer code (Works for one layer)

    map.on('click', function(evt) {
      var coordinate = evt.coordinate;
        //document.getElementById('info').innerHTML = '';
        var viewResolution = /** @type {number} */ (view.getResolution());
        var url = wmsSource1.getGetFeatureInfoUrl(
            evt.coordinate, viewResolution, 'EPSG:3857',
            {'INFO_FORMAT': 'text/html'});
        if (url) {
          document.getElementById('info').innerHTML =

                content.innerHTML = '';
                }
                });

      map.on('pointermove', function(evt) {
        if (evt.dragging) {
          return;
        }
        var pixel = map.getEventPixel(evt.originalEvent);
        var hit = map.forEachLayerAtPixel(pixel, function() {
          return true;
        });
        map.getTargetElement().style.cursor = hit ? 'pointer' : '';
      });
      map.addOverlay(popup);

Modified code for multiple layers

      map.on('click', function (evt) {
    var url = GetFeatureInfoUrl = 'http://localhost:8080/geoserver/County/wms'
        'evt.coordinate', 'viewResolution', 'viewProjection', 'EPSG:3857',
                {'INFO_FORMAT': 'text/html',
                'QUERY_LAYERS': 'County:Boundary,County:Regions,County:Constituencies,County:Towns'};
            if (url) {
          document.getElementById('info').innerHTML =
                content.innerHTML = '';
                    }
                    });

          map.on('pointermove', function(evt) {
            if (evt.dragging) {
              return;
            }
            var pixel = map.getEventPixel(evt.originalEvent);
            var hit = map.forEachLayerAtPixel(pixel, function() {
              return true;
            });
            map.getTargetElement().style.cursor = hit ? 'pointer' : '';
          });


texts:
Is there a way of zooming to the current geographical location of the device running QGIS?

I want to be able to zoom to where I am at any time and maybe set the zoom extents too.


texts: QField Compatible Devices / Requirements

texts: I recently purchase a Samsung Tab A 10.1 (2019) and can't open QField projects on it. After attempting to open my project file it gets stuck. I read a comment from opengis.ch from 2013 that "currently QGIS for android runs on ARM v7 tablets only. I currently have no time to make an x86 build". Is that still the case for the 2020 version? What are the device requirements to properly run QField? Or am I confusing my error with another common bug/error?


texts: Adding raster created in GRASS (within QGIS) back into to GRASS (within QGIS)?

texts:
I am trying to use GRASS within QGIS - I have created a mapset etc in accordance with these instructions from other posts, and I am trying to create a raster map from shapefile contour information to create a DEM (and eventually run a ZTV through r.viewshed!)

I have imported my shapefile contours into GRASS as vector using v.in.ogv.qgis and converted to raster using v.to.rast.attr.

However, as I clicked 'Show Output' to add the successfully created raster to my map (to then run r.surf.contour), my QGIS crashed, and when I open it again (and re-open QGIS mapset etc) I can't load the raster I have created.

When I navigate to the source folder, I can see that there has been a raster created, but when I drag into QGIS I get an error on compatible format.

I've also tried r.external and r.in.gdal to no avail - not recognized as a supported file format.

Is there any way I can use this raster?

It took a while to process so I'd rather not run again if I can help it!

I am a QGIS newbie.

I am using QGIS 2.10.1 PISA with OS Sierra.

EDIT: Now upgraded to QGIS 2.18 LAS PALMAS as suggested in comments, but problem still occurs.


texts: Exporting map with transparent background outside of polygon with QGIS?

texts:
I want to create a transparent output file (image) of the map with the outside border of the seven polygons being the overall border.

The rest of the background I want to be transparent (but within the polygon of the seven regions, the OSM layer is required).

I tried to follow other instructions but failed so far.

Any ideas?