Thank you Andrea. Thank you for your explanations about asking PostGIS directly and so on. It's a very good start for me!
> By the numbers you get it seems your data is in some projected coordinate system. Which one, I cannot know. Ah ok... Can it be Lambert93 (SRID = 310024140)? Cheers too, -- Lmhelp On 05/07/2011 6:53 PM, Andrea Aime wrote: > On Sat, May 7, 2011 at 6:31 PM, Lmhelp<[email protected]> wrote: >> Hi again, >> >> I just want here to put things a little bit clearer (I am a beginner, I >> hope it won't be too confused). >> >> I have: >> - a GeoServer layer L1 which data come from a PostGIS table T1 >> containing geometries of type "POINT" (points), >> - a GeoServer layer L2 which data come from a PostGIS table T2 >> containing geometries of type "MULTIPOLYGON" (French departments), >> - a GeoServer group of layers G containing these two layers L1 and L2. >> >> As a result, I want to display a map "containing" those two layers >> (using OpenLayers). >> >> I need to compute a bounding box FROM these data ((T1 and T2) or (L1 and >> L2) or (G)). >> I need to do this programmatically. >> The bounding box I'll get as a result has to fit exactly the displayed >> data, in my case a map of France with "points" on it. >> >> The bounding boxes computed by Geoserver in my case are (for both T1 and >> T2): >> +--------+-----------+-----------+-----------+ >> | Min X | Min Y | Max X | Max Y | >> +--------+-----------+-----------+-----------+ >> | 99,226 | 6,049,647 | 1,242,375 | 7,110,524 | >> +--------+-----------+-----------+-----------+ >> => I don't understand what these huge numbers are (what is their unit of >> measure, etc.)... > > These come from asking PostGIS directly. Depending on how you setup > the store they might be the result of: > > select AsText(force_2d(Envelope(ST_Estimated_Extent('schema', 'table', > 'column'))) > > or > > select ST_AsText(ST_Force_2D(Envelope(ST_Extent(column)::geometry)))) > from schema:table > > where you have to replace schema, table and column for your specific case > and be lenient since I've derived the queries from the code but did > not have time to > try them out (parenthesis might not be balanced and the like). > > The first query is run if you enabled "estimated extent" in the db, and uses > the > spatial index statistics to compute the bbox quickly, the second is run if the > first fails or if estimated extent is not enabled, and does a full > scan of the table > and computes an exact bounding box. > > By the numbers you get it seems your data is in some projected > coordinate system. > Which one, I cannot know. > > Cheers > Andrea ------------------------------------------------------------------------------ WhatsUp Gold - Download Free Network Management Software The most intuitive, comprehensive, and cost-effective network management toolset available today. Delivers lowest initial acquisition cost and overall TCO of any competing solution. http://p.sf.net/sfu/whatsupgold-sd _______________________________________________ Geoserver-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geoserver-users
