Re: [postgis-users] Elevation profiles from rasters

2014-08-23 Thread Rémi Cura
Hey, you can do it using plpython and python gdal binding. It could be a first step to evaluate if it is fast enough for you. Cheers, Rémi-c 2014-08-22 22:09 GMT+02:00 Rasmus Aveskogh ras...@defero.se: Hi! How hard/feasible would it be to implement elevation profile/drape line functionality

Re: [postgis-users] Comparing two Building Footprint Tables

2014-08-23 Thread Rémi Cura
Hey, I did something akin, I decided then for a 2 step process : find potential matches, then keep none or the better match. The problem is: given 2 tables A (old) and B(new), find a mapping between A and B, with the following limits: a building could be new, destroyed , same or changed. (Note

Re: [postgis-users] Comparing two Building Footprint Tables

2014-08-23 Thread David Siegel
Hi Clifford just a quick saturday morning thought: One approach is to use a hash function like SHA256. To get started I’d try something like this: 1. For each footprint get a text representation of the geometry 2. Compute and store the SHA256[1] hash of the text representation 3. Find those

Re: [postgis-users] Comparing two Building Footprint Tables

2014-08-23 Thread Clifford Snow
I had considered using addressing data to give each footprint a unique id, but yours does the same with one less step. i'm going to try Rémi-C solution as well. Thanks On Sat, Aug 23, 2014 at 3:51 AM, David Siegel david.sie...@artcom.de wrote: Hi Clifford just a quick saturday morning