GIS Stack Exchange
GIS Stack Exchange

Most Popular

more tags
1500 questions
17
votes
1 answer

rMaps choropleth with custom json

With R I want to make an animated choropleth map with the rMaps package and a custom map. I tried to follow the example of Diego Valle described here and to use the custom map info for Datamaps. However, the map does not display. But, the legend…
GPierre
  • 271
  • 1
  • 6
17
votes
2 answers

Create weighted Thiessen polygons?

I have a point shapefile and I create Thiessen (Voronoi) polygons programmatically using this scripting syntax: CreateThiessenPolygons_analysis (in_features, out_feature_class, fields_to_copy) However, each point is related with an area (i.e. the…
Demetris
  • 1,039
  • 4
  • 10
  • 21
17
votes
2 answers

Calculating the bounding box of GeoJSON object using JavaScript

I have Django app with Leaflet on the frontend and I need to calculate the bbox of a GeoJSON object so that I can pass the coordinates to map.fitBounds() I have tried some libs as well as trying the getBounds methods of certain objects in Leaflet,…
fccoelho
  • 1,237
  • 5
  • 13
  • 22
17
votes
2 answers

postgis update multipolygon with st_makevalid() gives error

I have a table with a few invalid geometries (empty rings, self-intersections). I'd like to fix them up something like this: update mytable set geomcolumn = st_makevalid(geomcolumn) where id = 123; and I get "ERROR: Geometry type…
MC5
  • 1,901
  • 1
  • 14
  • 23
17
votes
1 answer

PostGIS - how to effeciently ST_Union all overlapping polygons in a single table

My goal is take a single table and st_union all polygons that are either touching or close to each other into single polygons I'm a C# developer who is starting to learn about PostGIS. Using the code below, I was able to accomplish this, but it…
Carol AndorMarten Liebster
  • 273
  • 1
  • 2
  • 8
17
votes
2 answers

Are there any alternatives to ArcScene?

I think I've had it. I've been struggling to create polished scenes and flyover animations using the ESRI tools. SketchUp is great but it does not handle large datasets and most 3rd party models (3D DXF, COLLADA) do not retain spatial reference when…
Jakub Sisak GeoGraphics
  • 20,294
  • 20
  • 104
  • 180
17
votes
7 answers

What iOS (iPhone/iPad) app from the App Store can I use to collect data?

What iOS app from the iTunes App Store can I use to collect data (mainly points, perhaps photos) and later import them into my GIS? I am mainly interested in an out-of-the-box solution, not develop one using any API. Bonus if it already connects to…
Ragi Yaser Burhum
  • 15,339
  • 2
  • 59
  • 76
17
votes
2 answers

Snapping raster grids in R

I am trying to align two raster grids in R. Once aligned I would like to be able to add them together. I have tried to check whether making a stack would work: grid_snap <- stack(habi_sdw, Pop_sdw) And I get the following error: Error in…
DI1
  • 311
  • 1
  • 2
  • 4
17
votes
2 answers

Cleaning geometries in PostGIS?

I am trying to do some processing on some very large polygon layers. However I am running into various geometry errors such as: NOTICE: Ring Self-intersection at or near point 470396.52017068537 141300.52235257279 CONTEXT: PL/pgSQL function…
Mart
  • 596
  • 2
  • 4
  • 15
17
votes
5 answers

Repairing broken GDAL and PROJ.4 on Ubuntu?

I solved the library problem, but others remain, only vaguely related to that of PROJ.4 libraries are not loaded. I asked a follow-up question for these. My GDAL package and PROJ.4 library are damaged, which causes errors while trying to reproject…
Pavel V.
  • 1,517
  • 3
  • 16
  • 46
17
votes
2 answers

Detecting if point is on left or right side of line in PostGIS?

I have a linestring table and a point table in postgis. I know the closest line to any given point. What I need to know is on which "side" of that line is the point. I guess I have to do that by creating a perpendicular line from given point to the…
mofoyoda
  • 893
  • 7
  • 21
17
votes
3 answers

How fast should I expect PostGIS to geocode well-formatted addresses?

How fast should I expect PostGIS to geocode well-formatted addresses? I've installed PostgreSQL 9.3.7 and PostGIS 2.1.7, loaded the nation data and all states data but have found geocoding to be much slower than I anticipated. Did I set my…
aaryno
  • 836
  • 5
  • 13
17
votes
3 answers

Using ArcPy to get layer symbology?

Since ArcGIS 10 comes with the ArcPy package, I'm wondering it is possible to use ArcPy functions to get Symbology (i.e color, width...) of a layer?
VietThanh Le
  • 1,470
  • 12
  • 12
17
votes
4 answers

Switching career from web application to GIS developer?

I am a software developer with over 20 years building applications mostly in the web application space for various companies. I am trying to get a foot hold into the GIS software development space and I am looking for advice on the best way to…
Peter
  • 163
  • 4
17
votes
3 answers

Set of standard accessibility guidelines for online maps?

Recently I've been designing maps without navigation tools like the Zoom In/Out and Pan tools, or arrows to pan north, pan west, etc. Instead, most modern mapping APIs support the direct use of the map itself to handle navigation - drag the map to…
Stephen Lead
  • 21,119
  • 17
  • 113
  • 240
1 2 3
…
99 100