From c49d8978980a245e512ad5fe95167c1a6ddee5e0 Mon Sep 17 00:00:00 2001
From: Thomas Fischer <thomas.fischer@ufz.de>
Date: Wed, 24 Sep 2014 08:52:57 +0200
Subject: [PATCH] [MGT] Handle case where standard deviation of edge lengths is
very small.
---
MeshGeoToolsLib/HeuristicSearchLength.cpp | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/MeshGeoToolsLib/HeuristicSearchLength.cpp b/MeshGeoToolsLib/HeuristicSearchLength.cpp
index fad637711b3..3a19fc002bc 100644
--- a/MeshGeoToolsLib/HeuristicSearchLength.cpp
+++ b/MeshGeoToolsLib/HeuristicSearchLength.cpp
@@ -47,16 +47,20 @@ HeuristicSearchLength::HeuristicSearchLength(MeshLib::Mesh const& mesh)
}
const double mu (sum/edge_cnt);
- const double s (sqrt(1.0/(edge_cnt-1) * (sum_of_sqr - (sum*sum)/edge_cnt) ));
- // heuristic to prevent negative search lengths
- // in the case of a big standard deviation s
- double c(2.0);
- while (mu < c * s) {
- c *= 0.9;
+ const double helper (sum_of_sqr - (sum*sum)/edge_cnt);
+ if (helper < 0.0) {
+ _search_length = mu/2;
+ } else {
+ const double s (sqrt(helper/(edge_cnt-1)));
+ // heuristic to prevent negative search lengths
+ // in the case of a big standard deviation s
+ double c(2.0);
+ while (mu < c * s) {
+ c *= 0.9;
+ }
+ _search_length = (mu - c * s)/2;
}
- _search_length = (mu - c * s)/2;
-
DBUG("[MeshNodeSearcher::MeshNodeSearcher] Calculated search length for mesh \"%s\" is %f.",
_mesh.getName().c_str(), _search_length);
}
--
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