Sean, I seems that it's all about a version of GEOS that it's too old. I will try upgrading to the latest and try again. Thanks a lot! JP
On Mon, Dec 15, 2014 at 1:51 PM, Sean Gillies <sean.gill...@gmail.com> wrote: > > JP, > > Actually, you can call unary_union with an empty list in the latest > Shapely. > > >>> import shapely > >>> shapely.__version__ > '1.5.1' > >>> import shapely.geos > >>> shapely.geos.geos_version > (3, 4, 2) > >>> from shapely.ops import unary_union > >>> unary_union([]) > <shapely.geometry.collection.GeometryCollection object at 0x10c3b6050> > > In your case, the KeyError gets raised first (I believe because your GEOS > library is too old). Because cascaded_union has been aliased to unary_union > (in Shapely 1.4+), it's the same story there. > > On Mon, Dec 15, 2014 at 11:33 AM, Juan Pablo Caram <jpca...@gmail.com> > wrote: >> >> Hi Sean, >> >> Thanks for your response. What really concerns me here is that in case 1 >> (Newer GEOS and shapely) I cannot call cascaded_union (or unary_union) with >> an empty list. I could on earlier versions. >> >> Thanks, >> >> JP >> >> On Mon, Dec 15, 2014 at 12:15 PM, Sean Gillies <sean.gill...@gmail.com> >> wrote: >>> >>> Hi JP, >>> >>> As far as I can tell, the main difference between your cases is that in >>> case 2, the included GEOS lib has a version >= 3.3. GEOS 3.2.2 (which is >>> 4.5 years old, by the way) does not support unary union. >>> >>> See >>> https://github.com/Toblerity/Shapely/blob/master/shapely/geos.py#L721 >>> <https://github.com/Toblerity/Shapely/blob/master/shapely/geos.py#L72> >>> >>> I admit that the KeyError is not the most helpful of errors. >>> NotSupported might be bettter. I'll create a new issue in the tracker. >>> >>> On Sat, Dec 13, 2014 at 3:18 PM, Juan Pablo Caram <jpca...@gmail.com> >>> wrote: >>> >>>> Hi, >>>> >>>> Could someone give me some light into this: I'm getting very different >>>> behavior between versions/platforms for cascaded_union and unary_union. I >>>> would like to know what it the expected/latest/correct behavior. These are >>>> the two cases: >>>> >>>> CASE 1 >>>> ====== >>>> >>>> Os: Ubuntu 12.04 >>>> libgeos-c1: 3.2.2-3ubuntu1 >>>> shapely: 1.5.1 >>>> python: 2.7.3 >>>> >>>> >>> cascaded_union([]) >>>> >>>> --------------------------------------------------------------------------- >>>> ValueError Traceback (most recent call >>>> last) >>>> /home/jpcaram/flatcam/<ipython-input-4-0c768f786c71> in <module>() >>>> ----> 1 cascaded_union([]) >>>> >>>> /usr/local/lib/python2.7/dist-packages/shapely/ops.pyc in >>>> cascaded_union(self, geoms) >>>> 128 subs[i] = g._geom >>>> 129 collection = lgeos.GEOSGeom_createCollection(6, subs, L) >>>> --> 130 return >>>> geom_factory(lgeos.methods['cascaded_union'](collection)) >>>> 131 >>>> 132 def unary_union(self, geoms): >>>> >>>> /usr/local/lib/python2.7/dist-packages/shapely/geometry/base.pyc in >>>> geom_factory(g, parent) >>>> 53 # Abstract geometry factory for use with topological >>>> methods below >>>> >>>> 54 if not g: >>>> ---> 55 raise ValueError("No Shapely geometry can be created >>>> from null value") >>>> 56 ob = BaseGeometry() >>>> 57 geom_type = geometry_type_name(g) >>>> >>>> ValueError: No Shapely geometry can be created from null value >>>> >>>> >>> unary_union([]) >>>> >>>> --------------------------------------------------------------------------- >>>> KeyError Traceback (most recent call >>>> last) >>>> /home/jpcaram/flatcam/<ipython-input-6-9089513baa4e> in <module>() >>>> ----> 1 unary_union([]) >>>> >>>> /usr/local/lib/python2.7/dist-packages/shapely/ops.pyc in >>>> unary_union(self, geoms) >>>> 146 subs[i] = g._geom >>>> 147 collection = lgeos.GEOSGeom_createCollection(6, subs, L) >>>> --> 148 return >>>> geom_factory(lgeos.methods['unary_union'](collection)) >>>> 149 >>>> 150 operator = CollectionOperator() >>>> >>>> KeyError: 'unary_union' >>>> >>>> >>> cascaded_union([Point(0,0)]) >>>> <shapely.geometry.point.Point at 0x201d510> >>>> >>>> >>> unary_union([Point(0,0)]) >>>> >>>> --------------------------------------------------------------------------- >>>> KeyError Traceback (most recent call >>>> last) >>>> /home/jpcaram/flatcam/<ipython-input-9-858a4018548e> in <module>() >>>> ----> 1 unary_union([Point(0,0)]) >>>> >>>> /usr/local/lib/python2.7/dist-packages/shapely/ops.pyc in >>>> unary_union(self, geoms) >>>> 146 subs[i] = g._geom >>>> 147 collection = lgeos.GEOSGeom_createCollection(6, subs, L) >>>> --> 148 return >>>> geom_factory(lgeos.methods['unary_union'](collection)) >>>> 149 >>>> 150 operator = CollectionOperator() >>>> >>>> KeyError: 'unary_union' >>>> >>>> >>>> CASE 2: >>>> ======= >>>> >>>> Os: Windows 7 >>>> python: 2.7.6 >>>> shapely: 1.3.0 (Installer came with geos) >>>> >>>> >>> cascaded_union([]) >>>> <shapely.geometry.collection.GeometryCollection at 0x7708830> >>>> >>>> >>> unary_union([]) >>>> <shapely.geometry.collection.GeometryCollection at 0x7708ab0> >>>> >>>> >>>> >>>> In CASE 1, everything is newer except for the python version. Has the >>>> behavior of shapely/geos changed? >>>> >>>> Thank You, >>>> >>>> JP >>>> >>>> >>>> _______________________________________________ >>>> Community mailing list >>>> Community@lists.gispython.org >>>> http://lists.gispython.org/mailman/listinfo/community >>>> >>>> >>> >>> >>> -- >>> Sean Gillies >>> >>> _______________________________________________ >>> Community mailing list >>> Community@lists.gispython.org >>> http://lists.gispython.org/mailman/listinfo/community >>> >>> >> _______________________________________________ >> Community mailing list >> Community@lists.gispython.org >> http://lists.gispython.org/mailman/listinfo/community >> >> > > -- > Sean Gillies > > _______________________________________________ > Community mailing list > Community@lists.gispython.org > http://lists.gispython.org/mailman/listinfo/community > >
_______________________________________________ Community mailing list Community@lists.gispython.org http://lists.gispython.org/mailman/listinfo/community
