Changeset 2218:50f1a780a5ff in lemon-0.x for lemon/lp_cplex.cc

Timestamp:

09/21/06 16:46:28 (18 years ago)

Author:

athos

Branch:

default

Phase:

public

Convert:

svn:c9d7d8f5-90d6-0310-b91f-818b3a526b0e/lemon/trunk@2952

Message:

Interface to the cplex MIP solver: it is little, a bit sour but it is ours.

File:

• lemon/lp_cplex.cc (modified) (4 diffs)

lemon/lp_cplex.cc

@@ -270 +270 @@
     status = CPXlpopt(env, lp);
     //status = CPXprimopt(env, lp);
-#if CPX_VERSION >= 900
+#if CPX_VERSION >= 800
     if (status)
     {
@@ -417 +417 @@
   LpCplex::SolutionStatus LpCplex::_getPrimalStatus()
   {
+    //Unboundedness not treated well: the following is from cplex 9.0 doc
+    // About Unboundedness
+
+    // The treatment of models that are unbounded involves a few
+    // subtleties. Specifically, a declaration of unboundedness means that
+    // ILOG CPLEX has determined that the model has an unbounded
+    // ray. Given any feasible solution x with objective z, a multiple of
+    // the unbounded ray can be added to x to give a feasible solution
+    // with objective z-1 (or z+1 for maximization models). Thus, if a
+    // feasible solution exists, then the optimal objective is
+    // unbounded. Note that ILOG CPLEX has not necessarily concluded that
+    // a feasible solution exists. Users can call the routine CPXsolninfo
+    // to determine whether ILOG CPLEX has also concluded that the model
+    // has a feasible solution.
+
     int stat = CPXgetstat(env, lp);
-#if CPX_VERSION >= 900
+#if CPX_VERSION >= 800
     switch (stat)
     {
@@ -486 +501 @@
   {
     int stat = CPXgetstat(env, lp);
-#if CPX_VERSION >= 900
+#if CPX_VERSION >= 800
     switch (stat)
     {
@@ -515 +530 @@
   {
     int stat = CPXgetstat(env, lp);
-#if CPX_VERSION >= 900
+#if CPX_VERSION >= 800
     switch (stat)
     {