All Questions

I put 4 different layers into my ArcMap document, but only one of them will show up on the map! I should be seeing the other 3 layers as well. When I do a Zoom to layer, I can see one layer, but I ...

I would like to be able to script some things that are not exposed via arcgisscripting or ArcPy. How do I access ArcObjects from Python?

I want to start working on a web map at work to map some of our statistics by city. I have an idea, but I'm not exactly sure where to start. Are there any definitive resources that provide step ...

I have a Shapefile but its coordinate system is Unknown, and there is no *.prj file. How can I identify it now?

I have latitude and longitude as 19.0649070739746 and 73.1308670043945 respectively. In this case both coordinates are 13 decimal places long, but sometimes I also get coordinates which are 6 ...

I have spent around 2 days to find the way to open GDB (Esri geodatabase) in QGIS (or any other open source software) but still without success. I have downloaded the newest OSGeo4W installer and ...

I'm having trouble with the OpenLayers Plugin of Qgis and the map composer: If I create an OSM-background layer and if I want to export this, the OSM-Layer looks perfectly all right in the normal ...

I have a feature class with over 2,000 features, and I need to make them all individual feature classes based on a field. Is there a way to do this?

I have two shapefiles, Point and Polyline. I'm trying to populate my polyline layer with the point data ID (systemID) where the lines start to where they end; eg. create two columns (from and to). The ...

What's the difference between a projection and a datum?

I don't know so much about coordinate systems... In my office we use to deal with spatial data coming from archaeological sites. Each site has its own x-y-z coordinate system (GCS). Three simple ...

I wish to display a map in QGIS (world country shapefiles) showing all countries but centered on the Pacific area. I am not familiar with Proj4, so is there any way this can be done in QGIS?

I'm attempting to do a spatial join much like the example here: Is there a python option to "join attributes by location"?. However, that approach seems really inefficient / slow. Even ...

I am working on ownership data at a US county level. I have one shapefile per county that contains thousands of tax parcels. I need to dissolve the polygons representing parcels owned by the same ...

I have a non-georeferenced vector layer that I need to be georeferenced. With raster layers the task is easy and straightforward, but I have no idea what should I do with my vector layer. I have a few ...

I have a series of layers of lines (shapefiles) in My Project. The CRS of some are different and to merge them they all must have same CRS. When I use Processing/Toolbox/Qgis_algorithims/...

I have multiple polygons, all located offshore around the UK. I am trying to calculate the areas of these polygons in square kilometres, without splitting them by UTM zone. Is it possible to do this ...

I hope somebody has already figured this one out. I just installed Geoserver 2.9 on a vanilla Ubuntu 16.04 distro. The Geoserver 2.8 method of enabling CORS with the shanbe.hezoun class does no longer ...

I have data in LAS format with RGB values created from aerial photogrammetry using a UAV. I am trying to find a solution to extract the bare earth DEM from the point cloud. I have tried SAGA, ...

I am needing to auto increment a field based on groups within a feature class. I have 8 plots within a given polygon and I need to assign them an ID from 1-8 for each set of plots within each polygon. ...

I am wanting to find a latitude and longitude point given a bearing, a distance, and a starting latitude and longitude. This appears to be the opposite of this question (Distance between lat/long ...

How do I calculate areas of an area shapefile in square meters or in acres (ha)? I didn't find that functionality in the vector tools.

I am trying to loop through a shapefile, selecting each feature in turn and copying it to a temporary shapefile to by included in a union analysis. I'm using a cursor to find the ID name for each ...

I am trying to write a stand alone python script in windows 7 that uses qgis.core and various other qgis libraries. I have found an old question on this subject here: Writing standalone Python ...

Where can I start to learn ArcPy?

I'm trying to create a join/relate in QGIS where I have a shapefile of buildings and to that I would like to join a non-spatial table (.csv) containing people who work in each building. So I have ...

I'm looking for an algorithm which when given a latitude and longitude pair and a vector translation in meters in Cartesian coordinates (x,y) would give me a new coordinate. Sort of like a reverse ...

I've got a layer in QGIS that is comprised of points. Its attribute table doesn't have (show) the corresponding x and y coordinates for each point. Is there a way for me to extract a list of ...

The discussion at What is the difference between WGS84 and EPSG4326? shows that 4326 is just the EPSG identifier of WGS84.. Wikipedia entries for Google Maps and OpenStreetMap shows that they both ...

ArcGIS Desktop has the option of using basemaps from ArcGIS online. Does QGIS have any such options?

I wish to familiarize myself with the capabilities of QGIS up to and beyond QGIS version 3.0. Can you recommend some good web resources and tutorials that would show me QGIS' capabilities? I am ...

After learning about the US Census's TIGERLines datasets I've working with the following layers, from the USA data Country boundaries State boundaries County boundaries City boundaries ZipCode/...

I'm using OpenStreetMap and its vectorial road network and I'd like to implement a map matcher algorithm. Currently I'm able, for each GPS position, to retrieve the nearest road segment and ...

Can anyone explain how to install GDAL/OGR with Python on Windows? I have Windows Vista and I have tried following the information on the website and it does not seem to bind the exe files for me. ...

I read in a CSV file for linking to a .shp file. All the variables that are just numbers came in as text. How do I change the text variables to numeric in QGIS?

I have a polyline shapefile with about 20 kinds of roads. I would like to know how can I create automatically a vector file for each one. I am aware of how to do it using ArcGIS Desktop - see ...

I'm looking for spatial clustering algorithm for using it within PostGIS-enabled database for point features. I'm going to write plpgsql function that takes distance between points within the same ...

How to create, on the shape of a polygon, a regular grid of polygons/squares of an given size, in postgis? I have thought about a function like How to create regular point grid inside a polygon in ...

I am working on a computational model of the abundance of wild pollinators across a landscape. The model itself is complete, and I am now struggling with a post-processing step. I have my GDAL ...

Is there a way to perform a reclassify of a raster image in QGIS? In ArcGIS you can do that in Spatial analyst Tools→Reclass→Reclassify Any ideas?

First, I have a shapefile consisting of square grids and each grid has an ID. Second, I have a shapefile consisting of different zones (with IDs). A grid ID in the first shapefile can contain many ...

I have had no luck getting the buffer tool to accept anything but degrees as units of measure. I have found lots of stuff saying the layer needs to be reprojected and saved but it hasn't worked at ...

Convex Hull A convex hull of a shape is defined as: In mathematics, the convex hull or convex envelope for a set of points X in a real vector space V is the minimal convex set containing X (Wikipedia)...

I was wondering if there is such a thing as an shapefile PRJ to PostGIS SRID lookup table? Something that can translate the most standard shapefile PRJ definitions into the likely SRID. When using ...

I have a geotiff raster image that has a coordinate system with longitudes from 0 to 360. The horizontal center of the image is 180 longitude. See image below: I want to transform it to EPSG:4326 SRS ...

How can I extract values from a raster by points? I prefer not in Arcgis. I prefer in Qgis or Mapwindow or other open source gis.

I'm trying to define a projection in QGIS. I want to add North America Albers Equal Area Conic. From the spatialreference site I copied the proj4 line: +proj=aea +lat_1=20 +lat_2=60 +lat_0=40 +lon_0=-...

I wonder if there is somewhere an explanation for the parameters that can be set when running the Algorithm "Join Attributes by Location" in QGIS 2.18. I had a look here: Documentation QGIS Testing |...

I assume this is a basic question but I can't seem to find or recognize the solution. This site returns Point: X: -11705274.6374 Y: 4826473.6922 when you searching with the first key value of ...

I'm writing a script which must work outside of QGIS GUI. I call some API functions from qgis.core but I'd like to use the processing plugin. I'm able to import processing with sys.path.append() but ...