[postgis-users] ST_Buffer + grid problem
Pierre.Racine at sbf.ulaval.ca
Thu Mar 22 13:53:24 PDT 2012
1020x24798 so more than 25 000 000 polygons... or pixels...
So if I understand well you want to assign some values to each of those cells based on a vector coverage (of how many polygons)?
> -----Original Message-----
> From: postgis-users-bounces at postgis.refractions.net [mailto:postgis-users-
> bounces at postgis.refractions.net] On Behalf Of Ed Linde
> Sent: Thursday, March 22, 2012 4:43 PM
> To: PostGIS Users Discussion
> Subject: Re: [postgis-users] ST_Buffer + grid problem
> So far no proper raster, because the following failed, but maybe the polygon
> gives us an idea? This polygon is the extent of all the road geometries in
> Denmark. Also I remember that when you did the raster at your end you said it
> worked. Is 0.000036 degrees = 4m correct if I want to get a 4m by 4m cell sized
> uniform raster grid?
> select ST_AsRaster( ST_GeomFromText('POLYGON((8.07734039737749
> 54.4984986588244,8.07734039737749 57.7505109647578,15.1919565742587
> 57.7505109647578,15.1919565742587 54.4984986588244,8.07734039737749
> 54.4984986588244))'), 0.000036, 0.000036);
> On Thu, Mar 22, 2012 at 9:39 PM, Pierre Racine <Pierre.Racine at sbf.ulaval.ca>
> > Thanks. The raster I need to visualise is a 4m by 4m grid on the entire
> map of
> > Denmark! :) So do you classify that as a large raster? If so is there a
> way to see a
> > portion of it or something?
> > I just want to manually check for a few areas on the map that the
> > indeed works as expected and things haven't gone awry thanks to
> > differences or that I had degrees instead of meters or some such
> thing. Well, I
> > still have to first test if this GDAL upgrade will fix things and if make
> empty raster
> > .. makes a difference.
> That must be big but Danemark is a small country ;-) Only width and
> height tell you if a raster is big.
> In the database, your grid is a set of rectangular geometry (how many?)
> or just a big raster now (width & height)?
> postgis-users mailing list
> postgis-users at postgis.refractions.net
More information about the postgis-users