Changeset 2328:b4931ae52069 in lemon-0.x for lemon/lp_glpk.cc

Timestamp:

12/07/06 17:10:54 (17 years ago)

Author:

athos

Branch:

default

Phase:

public

Convert:

svn:c9d7d8f5-90d6-0310-b91f-818b3a526b0e/lemon/trunk@3104

Message:

Query functions have been implemented for GLPK (CPLEX breaks at the moment, I guess): These functions include:
retrieving one element of the coeff. matrix
retrieving one element of the obj function
lower bd for a variable
upper bound for a variable
lower and upper bounds for a row (these can not be handled separately at the moment)
direction of the optimization (is_max() function)

File:

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

lemon/lp_glpk.cc

@@ -214 +214 @@
   }
 
-  LpGlpk::Value LpGlpk::_getCoeff(int, int)
-  {
-    ///\todo This is not yet implemented!!!
+  LpGlpk::Value LpGlpk::_getCoeff(int row, int col)
+  {
+
+    int length=lpx_get_mat_row(lp, row, 0, 0);
+    
+    std::vector<int> indices(length + 2);
+    std::vector<Value> values(length + 2);
+    
+    lpx_get_mat_row(lp, row, &indices[0], &values[0]);
+    
+    //The following code does not suppose that the elements of the
+    //array indices are sorted
+    for (int i = 1; i <= length; ++i) {
+      if (indices[i]==col){
+        return values[i];
+      }
+    }
     return 0;
+
   }
 
@@ -263 +278 @@
 
   }
+
+  LpGlpk::Value LpGlpk::_getColLowerBound(int i)
+  {
+    int b=lpx_get_col_type(lp, i);
+      switch (b) {
+      case LPX_LO:
+      case LPX_DB:
+      case LPX_FX:
+        return lpx_get_col_lb(lp, i);   
+      default: ;
+        return -INF;
+      }
+  }
   
   void LpGlpk::_setColUpperBound(int i, Value up)
@@ -306 +334 @@
       }
     }
+  }
+
+  LpGlpk::Value LpGlpk::_getColUpperBound(int i)
+  {
+    int b=lpx_get_col_type(lp, i);
+      switch (b) {
+      case LPX_UP:
+      case LPX_DB:
+      case LPX_FX:
+        return lpx_get_col_ub(lp, i);   
+      default: ;
+        return INF;
+      }
   }
   
@@ -424 +465 @@
     }
 
+  }
+
+  void LpGlpk::_getRowBounds(int i, Value &lb, Value &ub)
+  {
+
+    int b=lpx_get_row_type(lp, i);
+    switch (b) {
+    case LPX_FR:
+    case LPX_UP:
+      lb = -INF;
+        break;
+    default: 
+      lb=lpx_get_row_lb(lp, i);
+    }
+
+    switch (b) {
+    case LPX_FR:
+    case LPX_LO:
+      ub = INF;
+        break;
+    default: 
+      ub=lpx_get_row_ub(lp, i);
+    }
+    
   }