[postgis-users] Make Empty Raster
Pierre.Racine at sbf.ulaval.ca
Fri Mar 23 08:20:10 PDT 2012
> create table vector_grid as
> SELECT (gvxy).geom geom, ((gvxy).x - 1) + (gvxy).y cellid FROM (SELECT
> ST_MakeEmptyRaster( 423152, 361936,
> 16,16,0,0, 32632) ) gvxy) foo;
> to get a "16 mt by 16 mt" grid. I calculated the height and width in meters. And I
> should approximately get 0.5 billion polygons!
> Y'day your calculation for 4x4 m^2 was saying 25 million polygons. Am not sure
> how you got that? Am I doing something wrong by projecting it to UTM
> coordinates first to compute euclidean height and width?
It should be ok now. I guess the other day 0.000036 was wrong.
> I also get error --> NOTICE: Raster do not have band 1. Returning null values
It's true and ok.
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