[postgis-users] A question on ST_RemEdgeModFace usability

[Sandro Santilli]

On Thu, Apr 12, 2012 at 11:31:14PM +0200, Andrea Peri wrote:

> Suppose to have this topology and every topogeometry is coincident
> with a single face
> 
>     +----e1-------+----e2-------+----e3-------+
>     |             |             |             |
>     |             |             |             |
>     |    F1       |    F2       |     F3      |
>     e13          e14           e15           e16
>     |             |             |             |
>     |             |             |             |
>     +-----e4------+----e5-------+-----e6------+
>     |             |             |             |
>     |             |             |             |
>     |     F4      |     F5      |     F6      |
>    e17           e18           e19           e20
>     |             |             |             |
>     |             |             |             |
>     +-----e7------+-----e8------+-----e9------+
>     |             |             |             |
>     |             |             |             |
>     |     F9      |     F8      |     F7      |
>    e21           e22           e23           e24
>     |             |             |             |
>     |             |             |             |
>     +-----e10-----+-----e11-----+-----e12-----+
> 
> topogeometry T1 = face F1, T2 = F2  and so on..
> 
> If I suppose to whan remove the edge e19.

The real question here is : why ?
Why do you want to remove edge e19 ? What's the goal ?

I guess what you really want is modifying T5 and T6 in some way.
How do you want to modify them ? I think that's the point.

You may want T5 to take all the space and T6 to disappear.
Or you may want T6 to take all the space and T5 to disappear.
Or you may want both to share the same unified space.
Or you may want to drop both.

So first do any of the above, and then you are free to remove the edge.

--strk; 

  ,------o-. 
  |   __/  |    Delivering high quality PostGIS 2.0 !
  |  / 2.0 |    http://strk.keybit.net - http://vizzuality.com
  `-o------'