void
GurobiBackend::initialize(unsigned int numVariables, VariableType variableType) {
if (gurobilog.getLogLevel() >= Debug)
setVerbose(true);
else
setVerbose(false);
_numVariables = numVariables;
// delete previous variables
if (_variables)
delete[] _variables;
// add new variables to the model
if (variableType == Binary) {
LOG_DEBUG(gurobilog) << "creating " << _numVariables << " binary variables" << std::endl;
_variables = _model.addVars(_numVariables, GRB_BINARY);
_model.update();
} else if (variableType == Continuous) {
LOG_DEBUG(gurobilog) << "creating " << _numVariables << " continuous variables" << std::endl;
_variables = _model.addVars(_numVariables, GRB_CONTINUOUS);
_model.update();
// remove default lower bound on variables
for (int i = 0; i < _numVariables; i++)
_variables[i].set(GRB_DoubleAttr_LB, -GRB_INFINITY);
} else if (variableType == Integer) {
LOG_DEBUG(gurobilog) << "creating " << _numVariables << " integer variables" << std::endl;
_variables = _model.addVars(_numVariables, GRB_INTEGER);
_model.update();
// remove default lower bound on variables
for (int i = 0; i < _numVariables; i++)
_variables[i].set(GRB_DoubleAttr_LB, -GRB_INFINITY);
}
LOG_DEBUG(gurobilog) << "creating " << _numVariables << " ceofficients" << std::endl;
}
void
GurobiBackend::initialize(
unsigned int numVariables,
VariableType defaultVariableType,
const std::map<unsigned int, VariableType>& specialVariableTypes) {
if (gurobilog.getLogLevel() >= Debug)
setVerbose(true);
else
setVerbose(false);
setMIPGap(optionGurobiMIPGap);
if (optionGurobiMIPFocus.as<unsigned int>() <= 3)
setMIPGap(optionGurobiMIPGap);
else
LOG_ERROR(gurobilog) << "Invalid value for MPI focus!" << std::endl;
setNumThreads(optionGurobiNumThreads);
_numVariables = numVariables;
// delete previous variables
if (_variables)
delete[] _variables;
// add new variables to the model
if (defaultVariableType == Binary) {
LOG_DEBUG(gurobilog) << "creating " << _numVariables << " binary variables" << std::endl;
_variables = _model.addVars(_numVariables, GRB_BINARY);
_model.update();
} else if (defaultVariableType == Continuous) {
LOG_DEBUG(gurobilog) << "creating " << _numVariables << " continuous variables" << std::endl;
_variables = _model.addVars(_numVariables, GRB_CONTINUOUS);
_model.update();
// remove default lower bound on variables
for (unsigned int i = 0; i < _numVariables; i++)
_variables[i].set(GRB_DoubleAttr_LB, -GRB_INFINITY);
} else if (defaultVariableType == Integer) {
LOG_DEBUG(gurobilog) << "creating " << _numVariables << " integer variables" << std::endl;
_variables = _model.addVars(_numVariables, GRB_INTEGER);
_model.update();
// remove default lower bound on variables
for (unsigned int i = 0; i < _numVariables; i++)
_variables[i].set(GRB_DoubleAttr_LB, -GRB_INFINITY);
}
LOG_DEBUG(gurobilog) << "setting special variable types" << std::endl;
// handle special variable types
unsigned int v;
VariableType type;
foreach (boost::tie(v, type), specialVariableTypes) {
char t = (type == Binary ? 'B' : (type == Integer ? 'I' : 'C'));
LOG_ALL(gurobilog) << "changing type of variable " << v << " to " << t << std::endl;
_variables[v].set(GRB_CharAttr_VType, t);
if (type == Integer || type == Continuous) {
// remove bounds, which might have been set by the default variable
// type being binary previously
_variables[v].set(GRB_DoubleAttr_LB, -GRB_INFINITY);
_variables[v].set(GRB_DoubleAttr_UB, GRB_INFINITY);
}
}
