Geographic Information Systems Weekly Newsletter
Geographic Information Systems Weekly Newsletter

Top new questions this week:

Reclassification of raster

Is there a better way to do this? I'm trying to create a script that will change classifications of a raster to: 0 for: 0,7-9,15-20,40,62-63,73,78-87,89-130,132-151,153-175,177-203,215,228,251-253 ...

arcpy spatial-analyst reclassify  
asked by rnr0004 4 votes
answered by GISGe 2 votes

From everywhere to everywhere in spatial network

ArcGIS Network Analyst question: I have a network dataset representing an archaeological site with ~500 buildings. Each doorway of these buildings represents a terminal node. I would like to simulate ...

network-analyst scripting  
asked by Steve Wernke 4 votes
answered by dmahr 2 votes

Automate Exporting of Rasters Using Renderer in ArcGIS

It is possible to export rasters in ArcMap by right clicking the layer-> Data-> Export: You can then click 'Use Renderer' check box to ensure the image you export uses the current ...

arcgis-desktop arcpy raster image  
asked by JKyllo 3 votes

Is it possible to mix italic and normal font in a label?

I have concatenate the values of two field like "BYKV_BTYP" || '/' || "FFH" Is it possible to draw the value of the column "FFH" in italic if it is not empty and the value of "BYKV_BTYP" ...

qgis labeling  
asked by klausk 3 votes
answered by MappaGnosis 2 votes

CRS not embedded by maptools in R

I'm using the maptools package in R to merge some data to a shapefile. When I open the original input shapefile in QGIS, QGIS automatically picks up on the CRS. When I open the output shapefile from ...

qgis coordinate-system r maptools  
asked by Tumbledown 3 votes
answered by rcs 3 votes

PostGIS - ST_Within or ST_Disjoint performance issues

I have a table of about 150,000 points in PostGIS with a spatial index and a SRID of 27700 (OS). I want to select the points that fall outside England and Wales. I have a multipolygon table with ...

postgis postgresql query  
asked by Steven Lee 3 votes
answered by Paul Ramsey 6 votes

Assigning values of points outside a buffer to points within a buffer

I have 10m buffers around line features and a point shapefile which has some points intersecting the buffer. I would like to take each point that falls within the buffer and assign it the value of the ...

arcgis-desktop arcgis-10.1 point buffer line  
asked by Pete 2 votes
answered by Maksim 1 vote

Greatest hits from previous weeks:

Creating Centrelines from Road Polygons/Casings?

I want to create center lines from road polygons. Are there any automated tools in ArcGIS for Desktop to do this? I am including a Screenshot of my vector file below.

arcgis-desktop road  
asked by Binoy 16 votes
answered by Binoy 8 votes

Get boundary of raster image as polygon in ArcGIS Desktop?

I have a rectangular raster image in ArcGIS. My question is: how can I produce a polygon which is just the extent of the raster image? That is, I want to have a polygon layer with a single ...

arcgis-desktop arcgis-10.0 raster polygon  
asked by robintw 9 votes
answered by Alex Markov 11 votes

Can you answer these?

ArcGIS Split Raster tool results in black rasters

I have a rather large raster that I am trying to split into small tiles in PNG format to upload to Autodesk Infrastructure. I came across the Split Raster tool and thought it would do exactly what I ...

arcgis-desktop raster tiles  
asked by Matt B 1 vote

ST_Split and looping problems PostGIS

I am a total PostGIS noob, and am having trouble understanding the finer points of SQL syntax. I am trying to take a large set of line data and clip it with a polygon. I then want to create a new ...

postgis postgresql  
asked by jovin 1 vote

Merge multiple geojson-polygons

Lets say I have a very big image With a polygon in it: I want to polygonize this very big image with gdal polygonize. But the image is too big, so I dont have enough memory to polygonize that ...

vector geojson merge  
asked by Selphiron 1 vote
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