[MOAB-dev] r6025 - MOAB/trunk/tools/mbcslam

[iulian at mcs.anl.gov]

Author: iulian
Date: 2013-03-06 14:57:17 -0600 (Wed, 06 Mar 2013)
New Revision: 6025

Modified:
   MOAB/trunk/tools/mbcslam/CslamUtils.cpp
Log:
due to rounding errors, this quantity under a sqrt, in l'Huiller formula, could turn negative



Modified: MOAB/trunk/tools/mbcslam/CslamUtils.cpp
===================================================================
--- MOAB/trunk/tools/mbcslam/CslamUtils.cpp	2013-03-06 18:58:38 UTC (rev 6024)
+++ MOAB/trunk/tools/mbcslam/CslamUtils.cpp	2013-03-06 20:57:17 UTC (rev 6025)
@@ -708,7 +708,10 @@
   if ((vA*vB)%vC < 0)
     sign = -1;
   double s = (a+b+c)/2;
-  double E = 4*atan(sqrt(tan(s/2)*tan((s-a)/2)*tan((s-b)/2)*tan((s-c)/2)));
+  double tmp = tan(s/2)*tan((s-a)/2)*tan((s-b)/2)*tan((s-c)/2);
+  if (tmp<0.)
+    tmp = 0.;
+  double E = 4*atan(sqrt(tmp));
   return sign * E * Radius*Radius;
 }