Method save

code/math/linear_program_io.cpp:105–241

bool LinearProgram::save(const std::string& file_name, bool simple_name /* = false*/) const {
	std::ofstream output(file_name.c_str());
	if (output.fail()) {
		std::cerr << "could not create/open file to save:\'" << file_name << "\'" << std::endl;
		output.close();
		return false;
	}

	const std::string& ext = details::extension(file_name);
	if (ext != "lp" && ext != "mps" && ext != "cip") {
		std::cerr << "unsupported format: \'" << ext << "\'" << std::endl;
		return false;
	}

	Scip* scip = 0;
	SCIP_CALL(SCIPcreate(&scip));
	SCIP_CALL(SCIPincludeDefaultPlugins(scip));

	// disable scip output to stdout
	SCIPmessagehdlrSetQuiet(SCIPgetMessagehdlr(scip), TRUE);

	// create empty problem 
	SCIP_CALL(SCIPcreateProbBasic(scip, name_.c_str()));

	// set the objective sense to maximize, default is minimize
//		SCIP_CALL(SCIPfreeTransform(scip));
	SCIP_CALL(SCIPsetObjsense(scip, objective_->sense() == LinearObjective::MINIMIZE ? SCIP_OBJSENSE_MINIMIZE : SCIP_OBJSENSE_MAXIMIZE));

	// create variables
	std::vector<SCIP_VAR*> scip_variables;
	for (std::size_t i = 0; i < variables_.size(); ++i) {
		const Variable* var = variables_[i];

		std::string name = var->name();
		if (simple_name)
			name = "x" + std::to_string(i);

		double lb, ub;
		var->get_bounds(lb, ub);

		SCIP_VAR* v = 0;
		//			SCIP_CALL(SCIPfreeTransform(scip));
		switch (var->variable_type())
		{
		case Variable::CONTINUOUS:
			SCIP_CALL(SCIPcreateVar(scip, &v, name.c_str(), lb, ub, 0.0, SCIP_VARTYPE_CONTINUOUS, TRUE, FALSE, 0, 0, 0, 0, 0));
			break;
		case Variable::INTEGER:
			SCIP_CALL(SCIPcreateVar(scip, &v, name.c_str(), lb, ub, 0.0, SCIP_VARTYPE_INTEGER, TRUE, FALSE, 0, 0, 0, 0, 0));
			break;
		case Variable::BINARY:
			SCIP_CALL(SCIPcreateVar(scip, &v, name.c_str(), 0, 1, 0.0, SCIP_VARTYPE_BINARY, TRUE, FALSE, 0, 0, 0, 0, 0));
			break;
		}
		// add the SCIP_VAR object to the scip problem
		SCIP_CALL(SCIPaddVar(scip, v));

		// storing the SCIP_VAR pointer for later access