Hi all,

I am in need of making maps from postgis data and am sort of stymied by the 
range of options and difficulty in finding an example. My apologies if its out 
there and I've just not been able to find it. My goal is to be able to plot 
multiple point, polygon, and possibly raster layers on a matplotlib figure. 

Iv'e tried Jose Gomez-Dans example 
(http://sites.google.com/site/jgomezdans/ogr,pythonymatplotlib) but he seems to 
be just using postgis to get the SRID of the display extent argument 
transformed. 

I've tried the example from here: 
http://trac.gispython.org/lab/browser/Shapely/trunk/examples/world.py?rev=749 
substituting an ExecuteSQL for GetLayersByName like this:

import ogr
import pylab
from numpy import asarray

from shapely.wkb import loads

source = ogr.Open("PG:host=localhost dbname=fb user=*** password= ***")
borders = source.ExecuteSQL("select std_id as stand, boundary from 
vaneck.vaneck_units")


fig = pylab.figure(1, figsize=(4,2), dpi=300)

while 1:
feature = borders.GetNextFeature()
if not feature:
break

geom = loads(feature.GetGeometryRef().ExportToWkb())
a = asarray(geom)
pylab.plot(a[:,0], a[:,1])

pylab.show()

but asarray cannot process the syntax:

Traceback (most recent call last):
File "<stdin>", line 20, in <module>
IndexError: invalid index



At this point I'm inclined to generate the wdb using a query via Psycopg 
(instead of the above OGR method) but am stuck trying to figure out how to plot 
the multi polygon returned to shapely using matplotlib.

I'd be most grateful for any suggestions.

Peter


-- 
Peter Tittmann

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