7,204 reputation
353147
bio website djq.me
location Cambridge, MA
age
visits member for 4 years, 4 months
seen 6 hours ago

interested in postgis, geodjango, qgis, python and R

cofounder of coUrbanize

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Feb
14
comment Using SearchCursor to access & export values in a raster table
Hi Ryan - First, does an attribute table definitely exist? Secondly, does it have to be in arcpy? You can just try a simple export from the attribute table if you urgently need the data. Thirdly, are you reading in the raster properly? You can't read in the file using the name unless you set the working directly properly using something like env.workspace = r"D:\DATA\\", after the line from arcpy import env
Feb
14
comment How can I calculate the average width of a polygon?
Thanks Scro, it's not currently in PostGIS, but it's pretty quick to load in. I think I'll try @whuber's approach first but I will compare it to the results from PostGIS (and thank you for the offer of SQL help, but I should be able to manage). Mainly trying to get the approach clear in my head first.
Feb
14
comment How can I calculate the average width of a polygon?
that's true! In this case, my centerlines are not the same length, but I could always join them as one, and split them per polygon.
Feb
14
comment How can I calculate the average width of a polygon?
Thanks @whuber that is a great answer and it has helped me to think about it a lot more clearly.
Feb
13
comment How can I calculate the average width of a polygon?
@DanPatterson I didn't see any question like this (many are related, of course). Did you mean that my question was flagged? I didn't understand your second line.
Feb
13
revised How can I calculate the average width of a polygon?
added 344 characters in body
Feb
13
revised How can I calculate the average width of a polygon?
edited title
Feb
13
asked How can I calculate the average width of a polygon?
Feb
13
comment How can I dynamically supply the value of mapextents to the Mapfile?
Thanks for the help thus far. So if I wanted to pass a polygon, how would it be structured? I see points are ...&map_layer[3]=FEATURE+POINTS+500000+1000000+END+TEXT+'A+test+point'+END&... but I can't see polygons anywhere (unless I'm missing something).
Feb
13
comment How to generate a thumbnail of an openlayers map?
wonderful! I look forward to it, thanks.
Feb
13
comment How to generate a thumbnail of an openlayers map?
I'd love to see other examples! I'm unfamiliar with the Openlayers development process, so I'm not sure if it's necessary for me to change all of my code so it works with this development version, or whether to wait....
Feb
13
answered How to generate a thumbnail of an openlayers map?
Feb
13
comment How can I dynamically supply the value of mapextents to the Mapfile?
For example, can I supply a user-draw polygon which is used to clip the raster? I notice the '%token%' parameter in your link - could I set '%token%' to the value of 'POLYGON((..,..,..,..)) ?
Feb
12
comment How can I dynamically supply the value of mapextents to the Mapfile?
Hi @unicoletti - I updated my question to illustrate the type of spatial query I am describing. I would like this query to work for non-rectangular regions also (though I am unsure if this is possible).
Feb
12
revised How can I dynamically supply the value of mapextents to the Mapfile?
added 432 characters in body
Feb
11
comment How can I enable Shapefile GUI Loader in pgadmin3?
I couldn't get the --with-gui flag to work on ubuntu. You could download the OpenGeo package opengeo.org/technology/suite/download and use the gui that comes with it, but it's not ideal.
Feb
11
comment Open source GIS tool for mapping health data
Hi @hhart - what kind of data sources do you have?
Feb
10
asked How can I dynamically supply the value of mapextents to the Mapfile?
Feb
10
revised Equally sized countries?
added 157 characters in body
Feb
9
answered Equally sized countries?