Regina, i use M for time. I always think about Z being some sort of altitude or height.
[]'s Luigi Castro Cardeles 2009/5/6 Paragon Corporation <[email protected]> > Kevin, > > I think you have a bogus proj install or your spatial_ref_sys table has > some > sort of z mentioned. > > I get > "SRID=4001;POINT(-122.689717977579 49.4265525863074 5)" > > Though I only have proj 4.6.0 and 4.6.1 installs (tested on 1.3.3 and > 1.4SVN) so can't be sure its not an issue with an older proj you have. > > Anyway does anyone actually use Z for time? I always use M since in theory > its not out of the question that we wouldn't transform Z since it is a > space > dimension. > > Thanks, > Regina > > > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Paul > Ramsey > Sent: Wednesday, May 06, 2009 2:04 AM > To: PostGIS Users Discussion > Subject: Re: [postgis-users] value of spatial index on 300, 000, 000 point > geometries > > Well, our versions differ, but that means nothing :) > > medford=# select postgis_proj_version(); > postgis_proj_version > ---------------------------- > Rel. 4.6.1, 21 August 2008 > (1 row) > > I'm also running 1.4SVN. And I can't recall if I installed the grid shift > files. > > P. > > On Tue, May 5, 2009 at 10:55 PM, Kevin Neufeld <[email protected]> > wrote: > > :) So if proj doesn't have z transformation then ... I have a bogus > > proj install or corrupt spatial ref definition? > > > > postgis=# select postgis_proj_version(); > > postgis_proj_version ------------------------- Rel. 4.4.9, 29 Oct > > 2004 > > (1 row) > > > > Since my answer is different than yours, something is amiss. > > > > > > Paul Ramsey wrote: > >> > >> On Tue, May 5, 2009 at 9:58 PM, Kevin Neufeld > >> <[email protected]> > >> wrote: > >> > >>> > >>> But (and folks can correct me if I'm wrong since the docs don't > >>> actually > >>> specify) transforms operate on *all* dimensions. > >>> postgis=# select st_asewkt(st_transform('SRID=3005;POINT(1240227 > >>> 495643 5)', 4001)); > >>> st_asewkt > >>> > >>> -------------------------------------------------------------------- > >>> -- > >>> SRID=4001;POINT(-122.689717977579 49.4258574870912 533.550271589169) > >>> (1 row) > >>> > >> > >> That's news to me and my version of PostGIS: > >> > >> medford=# select st_asewkt(st_transform('SRID=3005;POINT(1240227 > >> 495643 5)', 4001)); > >> st_asewkt > >> ------------------------------------------------------- > >> SRID=4001;POINT(-122.689717977579 49.4265525863074 5) > >> (1 row) > >> > >> My intuition was that reprojection would leave Z alone, since proj4 > >> has no z-transform capabilities. > >> > >> P. > >> _______________________________________________ > >> postgis-users mailing list > >> [email protected] > >> http://postgis.refractions.net/mailman/listinfo/postgis-users > >> > > > > _______________________________________________ > > postgis-users mailing list > > [email protected] > > http://postgis.refractions.net/mailman/listinfo/postgis-users > > > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users > > > > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users >
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