On Mon, Dec 12, 2011 at 6:42 AM, Stanislav Vanecek <s.vane...@dhi.cz> wrote: > Hi > I am using the ST_Reclass to create 3-band TIFF (for graphical > presentation) from 1 band grid 32BF (using algorithm described in 32BF > http://postgis.refractions.net/documentation/manual-svn/RT_ST_Reclass.ht > ml) > The problem is, then for the mapping both intervals in (reclassexpr > text) must be increasing - values from small to high is mapped to > colors from "small to high" = (black to white for example) - and I like > to have them in opposite order. > I am working with the big rasters (2000 x 2000 cells). In this case the > ST_Reclass is already not very fast - and when I try to use map algebra > it was very, very slow. > Did someone have idea how to speed up?
Standa, Can you post your SQL? I don't think there is anything restricting you from having your intervals from high to low instead of low to high, but I could be wrong. ST_Reclass should be faster than ST_MapAlgebra as all evaluations are done in C instead of going back and forth with the PostgreSQL server. -bborie -- Bborie Park Programmer Center for Vectorborne Diseases UC Davis 530-752-8380 bkp...@ucdavis.edu _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
