I'll assume this feature doesn't exist, so I've added an enhancement ticket: http://trac.gispython.org/lab/ticket/247
-Mike On 18 February 2011 13:09, Mike Toews <[email protected]> wrote: > Hi, > > I'm using Shapely to compare linestrings (e.g., contains) from > different sources. Unfortunately, as they are from different sources, > my comparisons are not as they expected due to precision loss. > > Is it possible to modify the GEOS precision model[1] in Shapely? I've > tested my work in JTS TestBuilder using a fixed scale of 100000.0, > which works perfectly. > > I'll provide an example for context. To see if A contains B, using > default double precision model: > A : LINESTRING (2804546.853088379 6342201.814086914, 2804586.597930257 > 6342227.426515108, 2804626.342772136 6342253.038943302, > 2804666.0876140143 6342278.651371496, 2804705.8324558926 > 6342304.26379969, 2804745.577297771 6342329.876227884, > 2804765.623917896 6342368.096008201, 2804789.0318718576 > 6342403.585924613, 2804826.622362667 6342430.003267048, > 2804841.9301757812 6342474.739379883) > B : LINESTRING (2804586.597930198 6342227.426515403, > 2804546.8530881978 6342201.814087403) > > A contains B = False > > Changing precision model to 100000.0: > > A : LINESTRING (2804546.85309 6342201.81409, 2804586.59793 > 6342227.42652, 2804626.34277 6342253.03894, 2804666.08761 > 6342278.65137, 2804705.83246 6342304.2638, 2804745.5773 6342329.87623, > 2804765.62392 6342368.09601, 2804789.03187 6342403.58592, > 2804826.62236 6342430.00327, 2804841.93018 6342474.73938) > B : LINESTRING (2804586.59793 6342227.42652, 2804546.85309 6342201.81409) > > A contains B = True > > Thanks! > -Mike > > [1] > http://geos.refractions.net/ro/doxygen_docs/html/classgeos_1_1geom_1_1PrecisionModel.html > _______________________________________________ Community mailing list [email protected] http://lists.gispython.org/mailman/listinfo/community
