6,764 reputation
244133
bio website djq.me
location Dublin, Ireland
age
visits member for 3 years, 10 months
seen 2 days ago

interested in postgis, geodjango, qgis, python, R and LaTeX.

twitter: @djq


Dec
14
comment How to generate a thumbnail of an openlayers map?
Are you using PostGIS to store the data? There is a PostGIS output to geoJson, and then using advice from @geographika's blog you can convert geoJson to png. geographika.co.uk/visualising-geojson-in-15-minutes
Dec
14
revised How to generate a thumbnail of an openlayers map?
added 59 characters in body
Dec
14
answered How to generate a thumbnail of an openlayers map?
Dec
14
answered What annoys you about your GIS Environment?
Dec
14
comment Exporting polygon features to individual image pngs
Perhaps you need to add an attribute column name in as an argument. The code above ran fine for me, but a more correct version might be to have spplot(demo, "fieldName")
Dec
14
comment Exporting polygon features to individual image pngs
Hmm, are you definitely reading the shapefile ok? To remove the border you can put the line trellis.par.set(axis.line=list(col=NA)) above spplot.... to remove the border. Glad it's of interest.
Dec
13
revised Exporting polygon features to individual image pngs
edited body
Dec
13
comment Exporting polygon features to individual image pngs
Hi @rasto Just curious - I saw your edit and as far I understand length(polygons(demo)) and length(demo) both return the same values. Are there cases when this is not true and you should choose one over there other?
Dec
13
answered Spatial Analyst Cell Statistics tool in Python gives inaccurate results
Dec
13
comment Spatial Analyst Cell Statistics tool in Python gives inaccurate results
Can you format your code using the {} button? At the moment, there is no indentation in your for loop. I don't know if that is due to formatting or your code.
Dec
12
comment Why is GPS a free service?
@nmpeterson Surprisingly it was Reagan, not Clinton who allowed it to be used for non-military purposes.
Dec
12
comment How to run two PostGIS versions in parallel on Windows?
I don't have a problem with the postgresql installations, just figuring out how to install postgis2.0. The question is now a bit muddled as I updated it along the way, perhaps I should rephrase it.
Dec
12
comment Converting a polygon into a raster using R
hmmm, I had a problem with the slash on both OSX and Windows.. not sure if we are using the same version or not.
Dec
12
revised Exporting polygon features to individual image pngs
added 108 characters in body
Dec
12
revised Exporting polygon features to individual image pngs
deleted 272 characters in body
Dec
12
answered Exporting polygon features to individual image pngs
Dec
12
awarded  Enthusiast
Dec
11
comment Random sampling of raster using R
This may be extremely obvious, but it took me some time to realize that the value of any cell can be referenced by r[r "condition"]. So if you want to set all value of the raster that are 100 to be 1 you can write r[r == 100] <- 1. Thanks @whuber - extremely useful example!
Dec
11
revised Converting a polygon into a raster using R
added 38 characters in body
Dec
11
accepted Converting a polygon into a raster using R