[Qgis-user] Union Tool - Ftools/Sextante - How should the real result be

[Ivan Santiago]

In this bug report:
http://hub.qgis.org/issues/4567 
there is a link with the data provided:
http://hub.qgis.org/attachments/5563/shapes_and_fake_polys.zip 

Giovanni Manghi updated the report:
...the tool is not wrong, in fact if you see in detail (see attached screenshot) the two polygons that seems wrong after the union are not identical in the input layers, there is a very small difference, something like 0.4 mm... but this makes them two non identical, overlapping polygons...

It would be  n i c e  if the use can provide a tolerance to the tool.  In this way, this would avoid some of the spurious data that appear when doing overlays.

---------------------------
Iván Santiago
GIS Specialist
Information Technologies
Office of Management and Budget
787.725.9420 x 2378
Calle Cruz 254
PO Box 9023228
San Juan, PR 00902-3228

-----Original Message-----
From: Victor Olaya [mailto:volayaf at gmail.com] 
Sent: Tuesday, May 07, 2013 10:02 AM
To: Ivan Santiago
Cc: senhor.neto at gmail.com; qgis-user at lists.osgeo.org
Subject: Re: [Qgis-user] Union Tool - Ftools/Sextante - How should the real result be

Ivan

could you provide some small dataset where you are seeing that?
Information about SEXTANTE version is also welcome (I assume you are using the latest QGIS master, but just in case...There is no need to reinstall SEXTANTE, just reinstall the latest QGIS dev, which includes
SEXTANTE)

Thanks!

2013/5/7 Ivan Santiago <isantiago at ogp.pr.gov>:
> Hello:
>
>
>
> I downloaded (now) and reinstalled Sextante.
>
>
>
> Unfortunately the results were the same, holding duplicate polygons 
> when using Union tool.
>
>
>
> It is easy to see the dups applying transparency.
>
>
>
>
>
> ---------------------------
> Iván Santiago
> GIS Specialist
> Information Technologies
> Office of Management and Budget
> 787.725.9420 x 2378
> Calle Cruz 254
> PO Box 9023228
> San Juan, PR 00902-3228
>
>