7,086 reputation
353147
bio website djq.me
location Cambridge, MA
age
visits member for 4 years, 3 months
seen 7 hours ago

interested in postgis, geodjango, qgis, python and R

cofounder of coUrbanize

tweet tweet: @djq


Dec
15
comment Creating map gores in ArcGIS for Desktop?
You might find this previous question useful: gis.stackexchange.com/questions/53578/…
Dec
1
comment Applying version control to ArcGIS Models
Could not agree more about the concept of reproducible research. To me it is the most compelling reason why researchers should be using OSS.
Nov
30
comment Looking for succesful implementaion of PPDM in form of geodatabase
Is PPDM an abbreviation of Professional Petroleum Data Management?
Nov
30
comment Modeling SQL Query to add statistical data to a geometry
Do you have to do it in SQL? It could be easier to do it in something like R, where you connect to the SQL DB, and have the ability to store intermediate results in dataframes throughout a script. Not saying it can't be done in SQL but long term, it might be more legible in another language.
Nov
29
comment Draw line overlays and center map
No need to apologize! We all have to start somewhere....
Nov
26
comment Best program or tool for visualising big data sets really fast 10-20 GB data if the users don't know squat about GIS?
I think this question needs to be much more specific to result in useful answers. 10-20 GB of mostly vector data is very vague. Are they points? Polygons? Do you want users to be able to choose cartographic styles? Zoom levels? See individual features? GPU considerations don't really seem relevant this early on.
Nov
26
comment Visualize large amount of geopoints with Geoserver and PostGIS
I expanded my answer to describe the general process
Nov
24
comment Simplifying geometries and calculating non-spatial averages
'zooming' suggests that you are viewing the data via a viewer of some sort; it's not an inherent property that you can calculate. If you have some spatial unit that you can aggregate upwards, perhaps you could use that? Can you post an example of the data illustrating the table structure?
Nov
20
comment Computing intersections for each geometry in a table
Out of curiosity, is a.id < b.id better than a.id != b.id as you will reduce the total number of queries?
Nov
13
comment List of useful Add-Ins for ArcGIS Desktop?
This is a four year old comment that's obsolete. While short, I don't think it needs to be expanded.
Nov
1
comment How to fix scaling mismatch of shape file layer & PostGIS table Lat/Lon data layer for India Map in Geoserver?
It's a little hard to understand your question (can you add screen shots of what you see and/or values that you are getting)? Check that you are using the same projection in both places; this is a common source of error.
Oct
11
comment installing GEOS, PROJ, GDAL/OGR into a python virtualenv on Mac OS X
I don't believe this addresses the issue of accessing gdal from within a virtualenv (I tried it and it did not work)
Oct
10
comment Generating a GDAL script through the QGIS Georeferencer
Also, another useful example: mapbox.com/blog/georeferencing-satellite-geoeye
Oct
10
comment Generating a GDAL script through the QGIS Georeferencer
btw, I recently asked a question using the same process. Might be a useful comparison: gis.stackexchange.com/questions/116672/…
Oct
9
comment Georeferencing a raster using GDAL and Python
@Luke so is there no way of interacting with these gdal utilities? I'd be happy to explore how to write a python wrapper for these if one does not exist.
Oct
7
comment Reclassify rasters using GDAL and Python
@gene I have looked at it - but I could not find any references to reclassifying rasters.
Apr
17
comment Workflow to convert a DWG CAD file to a shapefile
Is it also possible to directly save it as a shapefile?
Apr
12
comment Workflow to convert a DWG CAD file to a shapefile
Thanks, I'm familiar with Postgis, so happy to store it there; how do I go about using the ground control point with ogr2ogr? Do I need a point (or points) of reference for the geolocation and within the CAD file?
Apr
12
comment Workflow to convert a DWG CAD file to a shapefile
Unfortunately, I do not have access to ArcGIS either
Apr
8
comment Workflow to convert a DWG CAD file to a shapefile
Unfortunately I do not have Autocad map 3D, but it's useful to know it's possible within that software.