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<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt">Dear Postgis Community,<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt">I have two rasters and I want to create new raster using intersection through ST_MapALgepraExpre() function. The new raster should have pixel values as max pixel values from either of the
two rasters. I guess that I want to use product of these two rasters for what I want in new raster. I use following query and encounter the problem. I am sure there is something wrong in my query with expression. Can someone please guide me how to correct
it. My Postgis version is of data "2012-03-29 09:07:33" and raster lib build data "2012-03-29 09:07:33"<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt">With env as(<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt">select rid, gaztext_id, st_area(ST_Envelope(rast)) as area, rast from text_rast_intersection ),<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt">max_rast as(select e.rid, e.gaztext_id, e.rast as maxrast from env e, env b where e.area > b.area )<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt">,min_rast as (select e.rid, e.gaztext_id, e.rast as minrast from env e, env b where e.area < b.area )<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt">select '222' as rid, 964 as gaztext_id,
<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt">st_MapAlgebraExpr(a.maxrast,b.minrast,'minrast'*'mnaxrast', 'INTERSECTION', 'NULL', 'NULL', 'NULL') as rast from max_rast a, min_rast b<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt">ERROR:<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt">ERROR: operator is not unique: unknown * unknown<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt">LINE 14: st_MapAlgebraExpr(a.maxrast,b.minrast,'minrast'*'mnaxrast', ...<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt"> ^<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt">HINT: Could not choose a best candidate operator. You might need to add explicit type casts.<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt">********** Error **********<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt">ERROR: operator is not unique: unknown * unknown<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt">SQL state: 42725<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt">Hint: Could not choose a best candidate operator. You might need to add explicit type casts.<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt">Character: 468<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt">Thanks,<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt">Gaurav<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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