Brent,
select count(*) from v_images where not isvalid(wkb_geom_extent);
select count(*) from v_images where not isvalid(wkb_geom_extent) and not
isvalid(st_buffer(wkb_geom_extent, 0.0));
update v_images set wkb_geom_extent=st_buffer(wkb_geom_extent, 0.0)
where not isvalid(wkb_geom_extent);
You might want to backup your table first. If the second query returns
zero then it should fix all the problems. You might want to get a list
of the invalid ones and check them against the buffered ones also.
-Steve
On 6/12/2012 1:52 PM, Brent Fraser wrote:
Hi All,
I've got a table (a view actually) with two multipolygon geometry
columns: wkb_geom_extent and wkb_geom_digitized.
They contain polygons representing the footprint of images and the areas
digitized in the images.
So the view looks like:
v_images
image_id: wkb_geom_extent: wkb_geom_digitized:
1 xxxxx xxxx
2 xxxxx
3 xxxxxx xxxxx
I want to calculate the area digitized in each of the images and since
some of the polygons representing the area digitized could have be
sloppily defined to extend outside of the image footprint , I thought I
would intersect the two geometries:
SELECT image_id, ST_Intersection(wkb_geom_extent, wkb_geom_digitized) as
image_area FROM v _images
but I get an error:
NOTICE: TopologyException: side location conflict at -17.2242 79.1865
ERROR: GEOS Intersection() threw an error!
********** Error **********
ERROR: GEOS Intersection() threw an error!
SQL state: XX000
This may be due to some problems in my geometries, but I thought I would
check to see if my query was reasonable...
Thanks!
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