Documenting complementarity violations

Author: jajhall

highs/lp_data/HighsInterface.cpp

@@ -2896,6 +2896,15 @@ HighsStatus Highs::lpKktCheck(const HighsLp& lp, const std::string& message) {
             int(info.num_relative_dual_residual_errors),
             info.max_relative_dual_residual_error, dual_residual_tolerance);
       }
+      if (info.num_complementarity_violations) {
+	if (!this->options_.output_flag) {
+	  printf("Highs::lpKktCheck With basis num_complementarity_violations = %d\n",
+		 int(info.num_complementarity_violations));
+	  this->options_.output_flag = true;
+	  this->writeSolution("", 1);
+	  this->lpKktCheck(lp, message);
+	}
+      }
       assert(info.num_complementarity_violations == 0);
       assert(info.primal_dual_objective_error <= optimality_tolerance);
       if (have_residual_errors) {

highs/lp_data/HighsSolution.cpp

@@ -982,8 +982,14 @@ bool getComplementarityViolations(const HighsLp& lp,
     }
     const double dual_residual = std::fabs(dual);
     const double complementarity_violation = primal_residual * dual_residual;
-    if (complementarity_violation > optimality_tolerance)
+    if (complementarity_violation > optimality_tolerance) {
+      printf("getComplementarityViolations: %s %d has (primal / dual) residual (%g / %g) violation = %g\n",
+	     is_col ? "column" : "row",
+	     is_col ? int(iVar) : int(iRow),
+	     primal_residual, dual_residual,
+	     complementarity_violation);
       num_complementarity_violation++;
+    }
     max_complementarity_violation =
         std::max(complementarity_violation, max_complementarity_violation);
   }