[postgis-users] Same, similar et al

[Bob Pawley]

Hi Steve

FYI - I'm not involved in the geography side of Postgis, I'm developing an 
application to analyze engineering drawings. So, same in shape even if the 
shapes are spatially diverse is what I was looking for.

However, since this function doesn't exist I will need to develop something.

Thanks for the info.

Bob


-----Original Message----- 
From: Stephen Woodbridge
Sent: Wednesday, May 09, 2012 8:54 AM
To: postgis-users at postgis.refractions.net
Subject: Re: [postgis-users] Same, similar et al

On 5/9/2012 11:40 AM, Bob Pawley wrote:
> Hi
> I have two geoms that are similar in shape but don’t share the same
> space nor the same size.
> Is there a function or method to compare the two shapes in this 
> situation??
> The functions and operators I have found, seem to only look at spatial
> sameness.
> Or is my only option to spatially transfer and size one geometry to the
> other?
> Bob

Bob,

I don't think there is anything in PostGIS that does this. A bigger
question in my mind is how do you want to define "similar"? For example:

1. identical but scaled differently?
2. identical but positioned  or rotated differently?
3. topologically the same, ie: a coffee mug and donut have the same
topology but not the same shape
4. the same visual presentation but made up of different number of segments
5. and the list goes on and on

-Steve W
_______________________________________________
postgis-users mailing list
postgis-users at postgis.refractions.net
http://postgis.refractions.net/mailman/listinfo/postgis-users