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<P style="MARGIN-BOTTOM: 5pt; MARGIN-LEFT: 0in; MARGIN-RIGHT: 0in" class=MsoNormal><SPAN style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: black; FONT-SIZE: 10pt">I have a table of points extracted from a raster file. I perform the following SQL on the table</SPAN><SPAN style="FONT-FAMILY: 'Times New Roman','serif'; FONT-SIZE: 12pt"> </SPAN></P>
<P style="MARGIN-BOTTOM: 5pt; MARGIN-LEFT: 0in; MARGIN-RIGHT: 0in" class=MsoNormal><SPAN style="FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 10pt">CREATE TABLE weather_poly as</SPAN></P>
<P style="MARGIN-BOTTOM: 5pt; MARGIN-LEFT: 0in; MARGIN-RIGHT: 0in" class=MsoNormal><SPAN style="FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 10pt">SELECT(pixel_val, ST_Transform(ST_Union(ST_Buffer(shape, 0.1)),4326)) FROM</SPAN></P>
<P style="MARGIN-BOTTOM: 5pt; MARGIN-LEFT: 0in; MARGIN-RIGHT: 0in" class=MsoNormal><SPAN style="FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 10pt">weather_points GROUP BY pixel_val;</SPAN></P>
<P style="MARGIN-BOTTOM: 5pt; MARGIN-LEFT: 0in; MARGIN-RIGHT: 0in" class=MsoNormal><SPAN style="FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 10pt">The resulting polygon is 13 multi-polygons one for each pixel value instead of one polygon for every cluster of points.</SPAN></P>
<P style="MARGIN-BOTTOM: 5pt; MARGIN-LEFT: 0in; MARGIN-RIGHT: 0in" class=MsoNormal><SPAN style="FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 10pt">I can run the following SQL select ST_Dump(shape) from weather_poly a to break the polygons so they appear as separate polygons in Postgresql data view.</SPAN></P>
<P style="MARGIN-BOTTOM: 5pt; MARGIN-LEFT: 0in; MARGIN-RIGHT: 0in" class=MsoNormal><SPAN style="FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 10pt">When I try to view them in QGis the table does not show on the list of available PostGis layers. The properties of the table in Postgresql show the geometry to be ST_Dump not polygon.</SPAN></P>
<P style="MARGIN-BOTTOM: 5pt; MARGIN-LEFT: 0in; MARGIN-RIGHT: 0in" class=MsoNormal><SPAN style="FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 10pt">Is there a way to split the multi-polygon into individual polygons or to build the original polygons separatly so they will show in QGis and be accessable as such by GDAL based applications?</SPAN></P>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 10pt">Bruce</SPAN></P></FONT></DIV></BODY></HTML>
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