From 9741f86a2bdba9460945a0b64360a61c6b7a7d22 Mon Sep 17 00:00:00 2001
From: logari81 <logari81@e8eeb9e2-ec13-0410-a4a9-efa5cf37419d>
Date: Fri, 21 Oct 2011 10:52:11 +0000
Subject: [PATCH] + try to early detect and stop divergent solutions in freegcs
 (needs testing)

git-svn-id: https://free-cad.svn.sourceforge.net/svnroot/free-cad/trunk@5045 e8eeb9e2-ec13-0410-a4a9-efa5cf37419d
---
 src/Mod/Sketcher/App/freegcs/GCS.cpp | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/src/Mod/Sketcher/App/freegcs/GCS.cpp b/src/Mod/Sketcher/App/freegcs/GCS.cpp
index a2af83bfa..2c387de78 100644
--- a/src/Mod/Sketcher/App/freegcs/GCS.cpp
+++ b/src/Mod/Sketcher/App/freegcs/GCS.cpp
@@ -442,7 +442,7 @@ void System::initSolution(VEC_pD &params)
             if (params[i] != reduced_params[i])
                 reductionmap[params[i]] = reduced_params[i];
     }
- 
+
     int i=0;
     std::vector<Constraint *> clist0, clist1;
     for (std::vector<Constraint *>::const_iterator constr=clist.begin();
@@ -529,12 +529,15 @@ int System::solve(SubSystem *subsys, bool isFine)
 
     double convergence = isFine ? XconvergenceFine : XconvergenceRough;
     int maxIterNumber = MaxIterations * xsize;
-
+    double diverging_lim = 1e6*err + 1e12;
+
     for (int iter=1; iter < maxIterNumber; iter++) {
 
         if (h.norm() <= convergence || err <= smallF)
             break;
-
+        if (err > diverging_lim || err != err) // check for diverging and NaN
+            break;
+
         y = grad;
         subsys->calcGrad(grad);
         y = grad - y; // = grad - gradold
@@ -620,6 +623,7 @@ int System::solve(SubSystem *subsysA, SubSystem *subsysB, bool isFine)
 
     double convergence = isFine ? XconvergenceFine : XconvergenceRough;
     int maxIterNumber = MaxIterations * xsize;
+    double diverging_lim = 1e6*subsysA->error() + 1e12;
 
     double mu = 0;
     lambda.setZero();
@@ -685,7 +689,7 @@ int System::solve(SubSystem *subsysA, SubSystem *subsysB, bool isFine)
                 f = subsysB->error() + mu * resA.lpNorm<1>();
             }
             lambda = lambda0 + alpha * lambdadir;
- 
+
         }
         h = x - x0;
 
@@ -707,7 +711,10 @@ int System::solve(SubSystem *subsysA, SubSystem *subsysB, bool isFine)
             }
         }
 
-        if (h.norm() <= convergence && subsysA->error() <= smallF)
+        double err = subsysA->error();
+        if (h.norm() <= convergence && err <= smallF)
+            break;
+        if (err > diverging_lim || err != err) // check for diverging and NaN
             break;
     }