QGIS » QGIS Application

Union tool from fTools (and also SEXTANTE) produces wrong result. If we look at an accepted definition of "union" (http://resources.arcgis.com/en/help/main/10.1/index.html#//000800000010000000) and we will see that where features are overlapping, then in the union it is expected to have duplicated feature. In the attached result "union18", produced by QGIS 1.8, there areas where it is supposed to have overlapped/repeated features originating from overlapped parts in the input layers.



There is also some disscussion in mailing list about this http://osgeo-org.1560.x6.nabble.com/Union-Tool-Ftools-Sextante-How-should-the-real-result-be-tp5051653.html