Distance method of the Ray returns wrong results. #2950

akshayah3 · 2014-02-22T18:02:35Z

Consider this:
Ray((1,1), (2,2)).distance(Point(1.5, 3)) gives sqrt(17)/2
but the result should be 3*sqrt(2)/4

akshayah3 · 2014-02-22T22:01:15Z

@smichr Could you take a look at this?

smichr · 2014-02-23T04:31:33Z

sympy/geometry/line.py

            if self.contains(non_o):
-                return self.distance(o)  # = s.length but simpler
+                return s.length


I would leave this line alone: it says that calculating distance to o is simple than computing the length of s. Did you find otherwise?

That leads to an infinite recursion.

ah - it should be Line(self).distance(o)

>>> from sympy import * >>> Ray((1,1), (2,2)).distance(Point(1.5, 3)) 3*sqrt(2)/4

smichr · 2014-02-23T04:33:58Z

Good catch.

akshayah3 · 2014-02-23T05:28:14Z

@smichr So I guess you could merge this?

smichr · 2014-02-23T13:10:06Z

I made the change here, added the test and committed the result. Thanks for your improvements to geometry.

Distance method of the Ray returns wrong results.

ed5c15d

smichr reviewed Feb 23, 2014
View reviewed changes

smichr closed this Feb 23, 2014

akshayah3 deleted the Ray_distance branch February 23, 2014 14:42

Provide feedback