Now producing positive terms in simplex cost function

ERGO-Code · Dec 5, 2024 · a3d3fb5 · a3d3fb5
1 parent 593ec7b
commit a3d3fb5
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Showing 2 changed files with 35 additions and 20 deletions.
diff --git a/src/lp_data/HighsSolverStats.h b/src/lp_data/HighsSolverStats.h
@@ -24,6 +24,19 @@ enum HighsSolverStatsReport {
   HighsSolverStatsReportCsvData
 };
 
+enum HighsSimplexWorkTerm {
+  HighsSimplexWorkTermInvertNumRow = 0,
+  HighsSimplexWorkTermInvertNumNz,
+  HighsSimplexWorkTermComputePD,
+  HighsSimplexWorkTermBtran,
+  HighsSimplexWorkTermPrice,
+  HighsSimplexWorkTermFtran,
+  HighsSimplexWorkTermFtranDse,
+  HighsSimplexWorkTermCount
+};
+
+const std::vector<double> kSimplexWorkCoefficients = {1.0,2.0,3.0,4.0,5.0,6.0,7.0};
+
 struct HighsSimplexStats {
   bool valid;
   HighsInt num_col;
@@ -37,6 +50,7 @@ struct HighsSimplexStats {
   double row_ep_density;
   double row_ap_density;
   double row_DSE_density;
+  void workTerms(double* terms) const;
   double workEstimate() const;
   void report(FILE* file, const std::string message = "",
               const HighsInt style = HighsSolverStatsReportPretty) const;

diff --git a/src/simplex/HEkk.cpp b/src/simplex/HEkk.cpp
@@ -4483,25 +4483,26 @@ void HighsSimplexStats::initialise(const HighsInt iteration_count_) {
   row_DSE_density = 0;
 }
 
+void HighsSimplexStats::workTerms(double* terms) const {
+  const double nonbasic_nz = double(this->num_nz + this->num_row - this->last_factored_basis_num_el);
+  terms[HighsSimplexWorkTermInvertNumRow] = double(this->num_invert) * double(this->num_row);
+  terms[HighsSimplexWorkTermInvertNumNz] = double(this->num_invert) * this->last_factored_basis_num_el;
+  terms[HighsSimplexWorkTermComputePD] = double(this->num_invert) * double(this->last_invert_num_el + nonbasic_nz);
+  terms[HighsSimplexWorkTermBtran] = double(this->iteration_count) * double(this->last_invert_num_el) * this->row_ep_density;
+  terms[HighsSimplexWorkTermPrice] = double(this->iteration_count) * nonbasic_nz * this->row_ep_density;
+  terms[HighsSimplexWorkTermFtran] = double(this->iteration_count) * double(this->last_invert_num_el) * this->col_aq_density;
+  terms[HighsSimplexWorkTermFtranDse] = double(this->iteration_count) * double(this->last_invert_num_el) * this->row_DSE_density;
+}
+
+
 double HighsSimplexStats::workEstimate() const {
-  double work = 0;
-  // INVERT
-  work += num_invert * (2 * last_factored_basis_num_el + 2 * num_row);
-  // Compute primal
-  work +=
-      num_invert * (last_invert_num_el + num_nz - last_factored_basis_num_el);
-  // Compute dual
-  work +=
-      num_invert * (last_invert_num_el + num_nz - last_factored_basis_num_el);
-  // BTRAN
-  work += iteration_count * num_row * row_ep_density;
-  // PRICE
-  work +=
-      iteration_count * row_ep_density * (num_nz - last_factored_basis_num_el) +
-      num_col * row_ap_density;
-  // FTRAN
-  work += iteration_count * num_row * col_aq_density;
-  // FTRAN_DSE
-  work += iteration_count * num_row * row_DSE_density;
-  return work;
+   double* terms = new double[HighsSimplexWorkTermCount];
+   this->workTerms(terms);
+   double work = 0;
+   for (HighsInt iX = 0; iX < HighsSimplexWorkTermCount; iX++) {
+     assert(terms[iX]>0);
+     work += terms[iX] * kSimplexWorkCoefficients[iX];
+   }
+   delete[] terms;
+   return work;
 }