Change tolerance in overlap checking method to ensure results are relative to problem size

Author: robbievanleeuwen

sectionproperties/pre/pre.py

@@ -245,8 +245,9 @@ def remove_overlapping_facets(self):
                         self.remove_duplicate_facets()
 
                         if self.verbose:
-                            str = "Removed overlapping facets... Rebuilt with "
-                            str += "points: {0}".format(pts)
+                            str = "Removed overlapping facets {0}...".format(
+                                idx_to_remove)
+                            str += "Rebuilt with points: {0}".format(pts)
                             print(str)
 
                         # break both loops and loop through all facets again
@@ -447,6 +448,9 @@ def is_overlap(self, p, q, r, s, fct1, fct2):
         tol = 1e-3  # minimum angle tolerance (smaller is considered overlap)
         float_tol = 1e-12  # rounding error tolerance
 
+        # relativise tolerance by length of smallest vector
+        tol *= min(np.linalg.norm(r), np.linalg.norm(s))
+
         # are the line segments collinear?
         if abs(np.cross(r, s)) < tol:
             if abs(np.cross(q - p, r)) < tol: