[postgis-users] Size of a multipolygon

[Ben Madin]

Thanks Brent, Stephen,

Clearly the answer was much to straightforward for me to find!! I blame a poorly constructed question. Thank you.

On 02/05/2012, at 1:06 PM, pcreso at pcreso.com wrote:

> & FYI, I was interested in this post, as a PL/R user it may interest you as well?
> 
> http://www.spatialdbadvisor.com/postgis_tips_tricks/290/r-based-delaunay-triangulation-function-for-postgis-using-the-deldir-package 

Nice - I've used Regina's script before a couple of times, but I haven't had to worry about three dimensions.

Once to define approximate postcode boundaries for Australia - it's possible to obtain a list of postcode points, but Australia Post specifically declines to produce a map showing which areas are covered by which postcodes (mainly because they are not simply distributed by distance - some people get their mail by plane once a week, a live over 1000km from 'their' post-office. But they are outliers from an epidemiological perspective.

Also for mobile phone tower coverage - then truncating all the polygons at 35km from the centroid.

We now use PL/R almost exclusively for data output (except for interactive maps) on web sites - including tables.

cheers

Ben



> 
> Cheers,
> 
>   Brent
> 
> 
> --- On Wed, 5/2/12, Ben Madin <lists at remoteinformation.com.au> wrote:
> 
> From: Ben Madin <lists at remoteinformation.com.au>
> Subject: [postgis-users] Size of a multipolygon
> To: "PostGIS Users Discussion" <postgis-users at postgis.refractions.net>
> Date: Wednesday, May 2, 2012, 3:26 PM
> 
> Hello all,
> 
> I'm sure the answer is simple, but I'm lost on what to search on - I need to quickly search through several thousand multi polygons for any which have more than one part making them up. 
> 
> What is the best way to do this…? (I've tried array_length(), but don't seem to be able to feed it the right part. I can't believe I can't find a function that does it… or am I looking at dumping the multi polygons into a new table and counting the number of lines for each one...
> 
> cheers
> 
> Ben
> 
> 
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