Fix to irot3.isclose()

Former-commit-id: 5628e48141dac6dcc9726da999b6004b6cb445c9
2019-02-25 12:21:38 +02:00 · 2019-02-25 12:21:38 +02:00 · f31e800755
parent fe3f8e8c88
commit f31e800755
1 changed files with 5 additions and 1 deletions
--- a/qpms/qpms_c.pyx
+++ b/qpms/qpms_c.pyx
@ -855,5 +855,9 @@ cdef class irot3:
        '''
        if self.det != other.det: 
            return False
-        return self.rot.isclose(other.rot, rtol=rtol, atol=atol)
+        return (self.rot.isclose(other.rot, rtol=rtol, atol=atol)
+                # unit quaternions are a double cover of SO(3), i.e.
+                # minus the same quaternion represents the same rotation
+                or self.rot.isclose(-(other.rot), rtol=rtol, atol=atol)
+            )