From: Stefan Steiniger <sstein@ge...> - 2009-03-08 21:52:33
so .. I checked what is going on with your dataset when applying the
function Intersect Polygon Layers.
The reason while it fails and the error message appears is that the
"strbuffer" file contains features that overlay each other (you see the
overlay if you use the "union by attribute" function on strbuffer). If
they overlay the algorithm does not know what attribute values to chose
as there are two or more source objects.
The only thing I have done now, is to set the values that could have
come from 2 source features in a single layer to "NaN" for the resulting
The only way to solve the problem is by separating the features in
strBuffer that overlay and have different "dist" values into 2 (or more)
different layers. So that one layer - after applying an union by
attribute - would contain no overlaying features.
Note, you can get a intersection layer of strbuffer by
I) using "Union by Attribute" on strbuffer
II) using the union result with "Planar Graph" (but disabling the option
of attribute transfer since this would not work.. same problem as above)
III) clean up the layer that contains the faces from newly generated
polygons and assign the correct attribute values 
VI) use this one as input for the intersection
: error msg:'Found more than one source feature in Layer B'
: @ALL: Thinking about that, it seems like a polygon intersection
function is missing that works on a single layer. Or does anybody know a
function that would do that. [I guess I have the code probably
somwhere... But this is won't go into OJ 1.3]
RAVI KUMAR schrieb:
> Hi Stefan,
> 'waiting for the OJ 'Intersection of Polygon Layers', the shape files I have emailed you.
> My notes for 'OJ - Mineral Prognostication', is nearly ready.
> Hope this may be considered for suitability for a lab at the following.
> 'OGRS2009 Call For Research Papers, Showcases and Labs
> France July 8 to 10'.
> Ravi Kumar