From fff7f6a07efd6aa489f91f70b2c8f1e5503acddd Mon Sep 17 00:00:00 2001
From: Kaspar Fischer <fischerk@inf.ethz.ch>
Date: Tue, 21 Feb 2006 17:37:34 +0000
Subject: [PATCH] - fixed validity check (unboundedness)

---
 QP_solver/include/CGAL/QP_solver/QP_solver.C | 11 +++----
 QP_solver/include/CGAL/QP_solver/Validity.C  | 34 ++++++++------------
 2 files changed, 19 insertions(+), 26 deletions(-)

diff --git a/QP_solver/include/CGAL/QP_solver/QP_solver.C b/QP_solver/include/CGAL/QP_solver/QP_solver.C
index 1c777073817..6c96c28060f 100644
--- a/QP_solver/include/CGAL/QP_solver/QP_solver.C
+++ b/QP_solver/include/CGAL/QP_solver/QP_solver.C
@@ -2034,8 +2034,7 @@ z_replace_variable_original_by_original_upd_w_r(Tag_false )
     update_r_C_r_S_B__j_i(x_j, x_i);
     
     // replace r_beta_O(i) with w_j    
-    if (!check_tag(Is_linear())) // (kf.)
-      r_B_O[in_B[i]] = w[j];
+    r_B_O[in_B[i]] = w[j];
     
     // update x_O_v_i
     x_O_v_i[j] = BASIC;
@@ -2542,7 +2541,7 @@ check_r_C(Tag_false) const
 {
     Values                  t_r_C;
     // compute t_r_C from scratch
-    t_r_C.insert(t_r_C.end(), C.size(), et0);
+    t_r_C.resize(C.size(), et0);
     multiply__A_CxN_O(t_r_C.begin());
     
     // compare r_C and the from scratch computed t_r_C
@@ -2573,7 +2572,7 @@ check_r_S_B(Tag_false) const
 {
     Values                  t_r_S_B;
     // compute t_r_S_B from scratch
-    t_r_S_B.insert(t_r_S_B.end(), S_B.size(), et0);
+    t_r_S_B.resize(S_B.size(), et0);
     multiply__A_S_BxN_O(t_r_S_B.begin());
     
     // compare r_S_B and the from scratch computed t_r_S_B
@@ -2633,7 +2632,7 @@ check_r_B_O(Tag_false) const
 {
     Values                  t_r_B_O;
     // compute t_r_B_O from scratch
-    t_r_B_O.insert(t_r_B_O.end(), B_O.size(), et0);
+    t_r_B_O.resize(B_O.size(), et0);
     multiply__2D_B_OxN_O(t_r_B_O.begin());
     
     // compare r_B_O and the from scratch computed t_r_B_O
@@ -2664,7 +2663,7 @@ check_w(Tag_false) const
 {
     Values              t_w;
     // compute t_w from scratch
-    t_w.insert(t_w.end(), qp_n, et0);
+    t_w.resize( qp_n, et0);
     multiply__2D_OxN_O(t_w.begin());
     
     // compare w and the from scratch computed t_w
diff --git a/QP_solver/include/CGAL/QP_solver/Validity.C b/QP_solver/include/CGAL/QP_solver/Validity.C
index c8ac5bf80e3..35a6157e221 100644
--- a/QP_solver/include/CGAL/QP_solver/Validity.C
+++ b/QP_solver/include/CGAL/QP_solver/Validity.C
@@ -577,28 +577,22 @@ bool QP_solver<Rep_>::is_solution_unbounded()
 	has_finite_upper_bound(i) && w[i] < et0)
       return false;
 
-  // check unboundedness w^TDw=0 (C11):
-  Values Dw(qp_n, et0);     // Note: will be reused for (C12) below.
-  if (!check_tag(Is_linear())) {
-    for (int i=0; i<qp_n; ++i)
+  // check unboundedness 2 Dw=0 (C11):
+  if (!check_tag(Is_linear()))
+    for (int i=0; i<qp_n; ++i) {
+      ET sum = et0;
+      D_pairwise_accessor twoD(qp_D,i);
       for (int j=0; j<qp_n; ++j)
-	Dw[j] += w[i] * qp_D[j][i];
-    ET sum = et0;           // will hold w^T * Dw...
-    for (int i=0; i<qp_n; ++i)
-      sum += w[i] * Dw[i];
-    if (sum != et0)
-      return false;
-  }
-
-  // check unboundedness (c^T+2x^TD)w > 0 (C12):
-  ET m1 = et0, m2 = et0;
-  Value_const_iterator x_it = x_B_O.begin();
+	sum += w[j] * twoD(j);
+      if (sum != et0)
+	return false;
+    }
+  
+  // check unboundedness c^Tw > 0 (C12):
+  ET m = et0;
   for (int i=0; i<qp_n; ++i)
-    m1 += x[i] * Dw[i];
-  m1 *= et2;                  // Note: m1 contains 2x^TDw*d (and not 2x^TDw).
-  for (int i=0; i<qp_n; ++i)
-    m2 += w[i] * qp_c[i];
-  if (m2*d + m1 <= et0)
+    m += w[i] * qp_c[i];
+  if (m <= et0)
     return false;
 
   return true;