# [Gmsh] ReplaceDuplicatePoints malfunction

**Konstantinos Poulios**
logari81 at googlemail.com

*Wed Apr 28 22:06:19 CEST 2010*

After some further experimentation I tend to conclude that there is a
logical error in the way the avl tree is used in the case of
"allNonDuplicatedPoints". To my understanding, the comparison function
"comparePosition" which is used by this tree is not an appropriate
comparison function. The following 2D example demonstrates what I
mean:
Consider the points A(0,0), B(0.5,-1), C(1,-2) and eps = 0.6, in this
case using the function "comparePosition" to compare A, B and C in
pairs would yield to:
A > B (because A.X ~= B.X and A.Y > A.Y)
B > C (because B.X ~= C.X and B.Y > C.Y)
A < C (because A.X < C.X)
which is a logical error.
I will try to find some fix for the "comparePosition" function and try
it in praxis.
If I am indeed right with my considerations, it would be strange that
I am the first to experience crashes due to this problem.
Best Regards
Kostas