remove dead code; fix compilation with stats enables

ortools/glop/lu_factorization.cc

@@ -42,15 +42,15 @@ void LuFactorization::Clear() {
 }
 
 Status LuFactorization::ComputeFactorization(
-    const CompactSparseMatrixView& compact_matrix) {
+    const CompactSparseMatrixView& matrix) {
   SCOPED_TIME_STAT(&stats_);
   Clear();
-  if (compact_matrix.num_rows().value() != compact_matrix.num_cols().value()) {
+  if (matrix.num_rows().value() != matrix.num_cols().value()) {
     GLOP_RETURN_AND_LOG_ERROR(Status::ERROR_LU, "Not a square matrix!!");
   }
 
-  GLOP_RETURN_IF_ERROR(markowitz_.ComputeLU(compact_matrix, &row_perm_,
-                                            &col_perm_, &lower_, &upper_));
+  GLOP_RETURN_IF_ERROR(
+      markowitz_.ComputeLU(matrix, &row_perm_, &col_perm_, &lower_, &upper_));
   inverse_col_perm_.PopulateFromInverse(col_perm_);
   inverse_row_perm_.PopulateFromInverse(row_perm_);
   ComputeTransposeUpper();
@@ -58,10 +58,10 @@ Status LuFactorization::ComputeFactorization(
 
   is_identity_factorization_ = false;
   IF_STATS_ENABLED({
-    stats_.lu_fill_in.Add(GetFillInPercentage(compact_matrix));
+    stats_.lu_fill_in.Add(GetFillInPercentage(matrix));
     stats_.basis_num_entries.Add(matrix.num_entries().value());
   });
-  DCHECK(CheckFactorization(compact_matrix, Fractional(1e-6)));
+  DCHECK(CheckFactorization(matrix, Fractional(1e-6)));
   return Status::OK();
 }
 

ortools/glop/primal_edge_norms.cc

@@ -167,8 +167,8 @@ void PrimalEdgeNorms::ComputeDirectionLeftInverse(
 
   // TODO(user): Refactorize if estimated accuracy above a threshold.
   IF_STATS_ENABLED(stats_.direction_left_inverse_accuracy.Add(
-      ScalarProduct(direction_left_inverse_.values,
-                    matrix_.column(entering_col)) -
+      compact_matrix_.ColumnScalarProduct(entering_col,
+                                          direction_left_inverse_.values) -
       SquaredNorm(direction.values)));
   IF_STATS_ENABLED(stats_.direction_left_inverse_density.Add(
       Density(direction_left_inverse_.values)));

ortools/glop/revised_simplex.cc

@@ -827,7 +827,6 @@ bool RevisedSimplex::InitializeBoundsAndTestIfUnchanged(
   SCOPED_TIME_STAT(&function_stats_);
   lower_bound_.resize(num_cols_, 0.0);
   upper_bound_.resize(num_cols_, 0.0);
-  bound_perturbation_.AssignToZero(num_cols_);
 
   // Variable bounds, for both non-slack and slack variables.
   bool bounds_are_unchanged = true;
@@ -1436,25 +1435,6 @@ void RevisedSimplex::CorrectErrorsOnVariableValues() {
             << ", Primal residual |A.x - b| = "
             << variable_values_.ComputeMaximumPrimalResidual();
   }
-
-  // If we are doing too many degenerate iterations, we try to perturb the
-  // problem by extending each basic variable bound with a random value. See how
-  // bound_perturbation_ is used in ComputeHarrisRatioAndLeavingCandidates().
-  //
-  // Note that the perturbation is currently only reset to zero at the end of
-  // the algorithm.
-  //
-  // TODO(user): This is currently disabled because the improvement is unclear.
-  if (/* DISABLES CODE */ false &&
-      (!feasibility_phase_ && num_consecutive_degenerate_iterations_ >= 100)) {
-    VLOG(1) << "Perturbing the problem.";
-    const Fractional tolerance = parameters_.harris_tolerance_ratio() *
-                                 parameters_.primal_feasibility_tolerance();
-    std::uniform_real_distribution<double> dist(0, tolerance);
-    for (ColIndex col(0); col < num_cols_; ++col) {
-      bound_perturbation_[col] += dist(random_);
-    }
-  }
 }
 
 void RevisedSimplex::ComputeVariableValuesError() {
@@ -1553,14 +1533,8 @@ Fractional RevisedSimplex::ComputeHarrisRatioAndLeavingCandidates(
   for (const auto e : direction_) {
     const Fractional magnitude = std::abs(e.coefficient());
     if (magnitude <= threshold) continue;
-    Fractional ratio = GetRatio<is_entering_reduced_cost_positive>(e.row());
-    // TODO(user): The perturbation is currently disabled, so no need to test
-    // anything here.
-    if (false && ratio < 0.0) {
-      // If the variable is already pass its bound, we use the perturbed version
-      // of the bound (if bound_perturbation_[basis_[row]] is not zero).
-      ratio += std::abs(bound_perturbation_[basis_[e.row()]] / e.coefficient());
-    }
+    const Fractional ratio =
+        GetRatio<is_entering_reduced_cost_positive>(e.row());
     if (ratio <= harris_ratio) {
       leaving_candidates->SetCoefficient(e.row(), ratio);
 

ortools/glop/revised_simplex.h

@@ -627,11 +627,6 @@ class RevisedSimplex {
   DenseRow lower_bound_;
   DenseRow upper_bound_;
 
-  // The bound perturbation to be used for basic variable that are slightly
-  // outside their bounds. This contains small values that are non-zero only if
-  // the primal simplex ran into many degenerate iterations.
-  DenseRow bound_perturbation_;
-
   // Used in dual phase I to keep track of the non-basic dual infeasible
   // columns and their sign of infeasibility (+1 or -1).
   DenseRow dual_infeasibility_improvement_direction_;

ortools/glop/update_row.cc

@@ -72,7 +72,7 @@ void UpdateRow::ComputeUnitRowLeftInverse(RowIndex leaving_row) {
                                   unit_row_left_inverse_.values) -
       1.0));
   IF_STATS_ENABLED(stats_.unit_row_left_inverse_density.Add(
-      Density(unit_row_left_inverse_.values())));
+      Density(unit_row_left_inverse_.values)));
 }
 
 void UpdateRow::ComputeUpdateRow(RowIndex leaving_row) {