[postgis-users] Simple Point Density Surface

JamesH james.holmes at newcastle.ac.uk
Wed Apr 25 11:49:04 PDT 2012


"Why not convert the raster cell centers to points , do a query on the 
point layer for a square centered on the raster derived point  whose 
dimensions are given by the number of tiles in your neighborhood.  return 
the number of points divided by the area of the square.  ( neighborhoods 
are usually odd numbers of cells, 3x3, 5x5, etc so you have an equal 
number around the center cell)"

Thanks for the reference Doug. What you suggest does sound like it could
work, the only thing is that 
I would need to have this output as a Raster as I am then looking to use it
with two other rasters 
to do a weighted combination of them e.g. [rast1 * 0.2] + [rast2 * 0.5] +
[rast3 * 0.3].

Do you know how if I could easily rasterise the output of what you've
suggested?

Only reason is I'm working on it for a dissertation project and I've left
myself little time left to consider this.

Kind Regards,
James 


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