Hi Sean: But do you think the TopologyException for this input is a correct behavior ? If yes do you know why it happens and what is the meaning of depth in the message:
ERROR:shapely.geos:TopologyException: depth mismatch at at 581037.39250326285 4509301.9737485535 2014-04-28 16:59 GMT-04:00 Sean Gillies <sean.gill...@gmail.com>: > Thanks for the report, debugging, and support! I've got the fix here at > https://github.com/Toblerity/Shapely/issues/128. > > > On Mon, Apr 28, 2014 at 1:47 PM, Alex Flint <alex.fl...@gmail.com> wrote: > >> Ah, this seems to be a bug in shapely -- WindowsError is not defined >> except on windows. I patched line 115 of linestring.py replacing >> "WindowsError" with "OSError". (This is literally the only patch I've >> applied to my shapely install.) >> >> >> On Mon, Apr 28, 2014 at 3:44 PM, Oleksandr Huziy >> <guziy.sa...@gmail.com>wrote: >> >>> I have to mention that I am running your script using ipython notebook, >>> apparently it gives better exception information. >>> >>> Here is the notebook with the full exception. >>> >>> >>> http://nbviewer.ipython.org/urls/raw.githubusercontent.com/guziy/PyNotebooks/master/shapely_test.ipynb?create=1 >>> >>> Cheers >>> >>> >>> 2014-04-28 15:31 GMT-04:00 Oleksandr Huziy <guziy.sa...@gmail.com>: >>> >>> I am using Python 2.7.6 and shapely 1.3.1. >>>> >>>> What I also noticed that if you increase the distance to 10000 the >>>> error also disappears... >>>> >>>> Cheers >>>> >>>> >>>> 2014-04-28 15:24 GMT-04:00 Alex Flint <alex.fl...@gmail.com>: >>>> >>>> Sorry, python 2.7.6. >>>>> >>>>> >>>>> On Mon, Apr 28, 2014 at 3:23 PM, Alex Flint <alex.fl...@gmail.com>wrote: >>>>> >>>>>> Hmm that's strange, I haven't seen that error. What version of >>>>>> shapely are you using (I'm using 1.3.0). Also I'm on python 1.7.6. >>>>>> >>>>>> Attaching the exact python script that I am running at my end. >>>>>> >>>>>> I have also found that if I add small random numbers to each element >>>>>> of the data array (gaussian random numbers of order 1e-2) then I do not >>>>>> get >>>>>> the crash (and in fact I get the correct result), which suggests to me >>>>>> that >>>>>> this is some instability/round-off issue. >>>>>> >>>>>> Alex >>>>>> >>>>>> >>>>>> >>>>>> On Mon, Apr 28, 2014 at 3:12 PM, Oleksandr Huziy < >>>>>> guziy.sa...@gmail.com> wrote: >>>>>> >>>>>>> I get this error message when executing your code: >>>>>>> >>>>>>> ERROR:shapely.geos:TopologyException: depth mismatch at at >>>>>>> 581037.39250326285 4509301.9737485535 >>>>>>> >>>>>>> >>>>>>> Have no idea what this means, but maybe you know)) >>>>>>> >>>>>>> Cheers >>>>>>> >>>>>>> >>>>>>> 2014-04-28 14:55 GMT-04:00 Alex Flint <alex.fl...@gmail.com>: >>>>>>> >>>>>>>> The following code produces an exception under shapely (python >>>>>>>> version) 1.3.0 >>>>>>>> >>>>>>>> import shapely.geometry >>>>>>>> path = shapely.geometry.LineString([ >>>>>>>> [581037.19575668662, 4509299.98342364], >>>>>>>> [580996.61134201661, 4509304.202782942], >>>>>>>> [581037.19575668662, 4509299.98342364], >>>>>>>> [581072.19594137045, 4509296.7024005251], >>>>>>>> [581072.19594137045, 4509296.7024005251], >>>>>>>> [581037.19575668662, 4509299.98342364] >>>>>>>> ]) >>>>>>>> path.parallel_offset(2, shapely.geometry.JOIN_STYLE.mitre) >>>>>>>> >>>>>>>> The exception is: >>>>>>>> >>>>>>>> File >>>>>>>> "/Users/alexflint/Code/wifi-localization/tools/localization/estimation/scripts/shapely_bug.py", >>>>>>>> line 39, in <module> >>>>>>>> linestring.parallel_offset(2, >>>>>>>> shapely.geometry.JOIN_STYLE.mitre) >>>>>>>> File >>>>>>>> "/usr/local/Cellar/python/2.7.6/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/shapely/geometry/linestring.py", >>>>>>>> line 114, in parallel_offset >>>>>>>> bool(side == 'left'))) >>>>>>>> File >>>>>>>> "/usr/local/Cellar/python/2.7.6/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/shapely/geometry/base.py", >>>>>>>> line 55, in geom_factory >>>>>>>> raise ValueError("No Shapely geometry can be created from >>>>>>>> null value") >>>>>>>> ValueError: No Shapely geometry can be created from null value >>>>>>>> >>>>>>>> The points on the path above are actually very close to collinear, >>>>>>>> but my understanding was that parallel_offset should work regardless. I >>>>>>>> have attached a plot of the path itself. >>>>>>>> >>>>>>>> Any suggestions for what's going on here? >>>>>>>> >>>>>>>> Alex >>>>>>>> >>>>>>>> >>>>>>>> _______________________________________________ >>>>>>>> Community mailing list >>>>>>>> Community@lists.gispython.org >>>>>>>> http://lists.gispython.org/mailman/listinfo/community >>>>>>>> >>>>>>>> >>>>>>> >>>>>>> >>>>>>> -- >>>>>>> Sasha >>>>>>> >>>>>>> _______________________________________________ >>>>>>> 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 >>>>> >>>>> >>>> >>>> >>>> -- >>>> Sasha >>>> >>> >>> >>> >>> -- >>> Sasha >>> >>> _______________________________________________ >>> 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 > > -- Sasha
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