Hello Ernesto, I was also testing every option of the tool. I am afraid but we do not have enough documentation to determine the exact behavior of some of the options. As you say, they may need some adjustments.
-- Lucía Martínez Palomero Proyecto gvSIG Consellería de Infraestructuras y Transportes (GVA) Valencia (Spain) El 18/05/11 14:08, ernesto sferlazza escribió: > Hello users and developers > I have performed some trials to test how actually work the various > operators (or topological rules) implemented in the "spatial > selection" tool . > > - Operators "are the same as" and "intersect with": they works as I > expected for all kinds of geometries. > > - Operator "are disjoint from": the spatial query returns an error > (java.lang.NullPointerException) when I compare input layers > (polygons, lines or points)with polygons selected in a mask layer. > If I compare an input layer with features selected in the mask layer > (lines or points), the spatial query performed with the above > mentioned topological criterion returns all feature from the input > layers, despite some of them touch or intersect almost one feature of > the mask layer. > Maybe I have not understood its correct meaning: how really it should works? > > - Operator "touch": points (in the input layer) are selected if they > touch a vertex (but not simply the edge) of a polygon (in the mask > layer)or one of the endpoints (but not other intermediate vertices) of > a line feature (in the mask layer). If the mask layer is a point > layer, no feature is selected from point input layer even if we have > coincident points. > Lines from the input layer result selected if one of their endpoint > touch, in the mask layer, the endpoint (not an intermediate vertex) of > a line feature , or a single point, or a vertex (not simply the edge) > of the boundary of a polygon feature. > Using a polygon layer as input and a polygon layer as mask, "touch" > select only polygons for which only a segment (side) of the perimeter > of the input polygon is contained in a larger segment of the mask > polygon, but not the reciprocal (very strange behaviour); if the rest > of the input polygon overlaps the mask polygon, no selection occurs. > Using polygon layer as input and line layer as mask, the polygons > selected by "touch" are those for which lthe line (mask) feature lies > entirely on the perimeter of the polygon or if the end of the line > touches the vertex of the polygon and the line is not overlapped to > the interior of the polygon. > Using polygon layer as input and point layer as mask, polygons are > selected if one vertex of the perimeter is coincident with one point > of the mask layer. > > -Operator "cross over": lines (input) are selected if an endpoint > touches the edge or the interior (not the vertex) of a polygon (mask), > or if any point of the line touches a vertex of a polygon, but not if > an intermediate vertex of the line touches the edge of a polygon or if > only the endpoint of the line touches the vertex of a polygon. > [...] to be continued > > Have I misunderstood something on how operators work, or really some > adjustment to the rules of spatial query are needed? > > Best regards > -- Lucía Martínez Palomero Proyecto gvSIG Consellería de Infraestructuras y Transportes (GVA) Valencia (Spain) _______________________________________________ Gvsig_internacional mailing list [email protected] http://listserv.gva.es/cgi-bin/mailman/listinfo/gvsig_internacional
