diff --git a/src/storm/solver/GlpkLpSolver.cpp b/src/storm/solver/GlpkLpSolver.cpp index 3b40fbb56..62518fba6 100644 --- a/src/storm/solver/GlpkLpSolver.cpp +++ b/src/storm/solver/GlpkLpSolver.cpp @@ -419,6 +419,23 @@ namespace storm { } incrementalData.pop_back(); update(); + // Check whether we need to adapt the current basis (i.e. the number of basic variables does not equal the number of constraints) + int n = glp_get_num_rows(lp); + int m = glp_get_num_cols(lp); + int nb(0), mb(0); + for (int i = 1; i <= n; ++i) { + if (glp_get_row_stat(lp, i) == GLP_BS) { + ++nb; + } + } + for (int j = 1; j <= m; ++j) { + if (glp_get_col_stat(lp, j) == GLP_BS) { + ++mb; + } + } + if (n != (nb + mb)) { + glp_std_basis(this->lp); + } } } diff --git a/src/test/storm/solver/GlpkLpSolverTest.cpp b/src/test/storm/solver/GlpkLpSolverTest.cpp index a1cea5371..058fc2870 100644 --- a/src/test/storm/solver/GlpkLpSolverTest.cpp +++ b/src/test/storm/solver/GlpkLpSolverTest.cpp @@ -259,8 +259,8 @@ TEST(GlpkLpSolver, Incremental) { ASSERT_TRUE(solver.isOptimal()); EXPECT_EQ(12.0, solver.getContinuousValue(x)); - ASSERT_NO_THROW(y = solver.addUnboundedContinuousVariable("y")); solver.push(); + ASSERT_NO_THROW(y = solver.addUnboundedContinuousVariable("y")); ASSERT_NO_THROW(solver.addConstraint("", y <= solver.getConstant(6))); ASSERT_NO_THROW(solver.addConstraint("", x <= y)); // max x s.t. x<=12 and y <= 6 and x <= y @@ -296,12 +296,17 @@ TEST(GlpkLpSolver, Incremental) { ASSERT_NO_THROW(solver.addConstraint("", z <= solver.getConstant(6))); ASSERT_NO_THROW(solver.addConstraint("", x <= z)); ASSERT_NO_THROW(solver.optimize()); - // max x s.t. x<=12 and y <= 6 and x <= y + // max x s.t. x<=12 and z <= 6 and x <= z ASSERT_TRUE(solver.isOptimal()); EXPECT_EQ(6.0, solver.getContinuousValue(x)); EXPECT_EQ(6, solver.getIntegerValue(z)); solver.pop(); + ASSERT_NO_THROW(solver.optimize()); + // max x s.t. x<=12 + ASSERT_TRUE(solver.isOptimal()); + EXPECT_EQ(12.0, solver.getContinuousValue(x)); + solver.pop(); // max x s.t. true ASSERT_NO_THROW(solver.optimize());