/// <summary>
/// Creates a new model from the given file.
/// Supported file extensions: .mps only.
/// </summary>
/// <param name="fileName">The mps file to be imported.</param>
/// <param name="variables">The full array of variables created for this new model.</param>
/// <returns>The new model, or null if an error occurred.</returns>
public static Model New(string fileName, out Variable[] variables)
{
string fileNameWithoutExtension = Path.GetFileNameWithoutExtension(fileName);
string extension = Path.GetExtension(fileName).ToLower();
Model model = null;
if (extension.Equals(".mps"))
{
#region New Model from .mps file
string directoryName = Path.GetDirectoryName(fileName);
if (directoryName.Length == 0)
{
directoryName = ".";
}
string fullPathWithoutExtension = Path.Combine(directoryName, fileNameWithoutExtension);
CoinMpsIO m = new CoinMpsIO();
log.PassToCoinMpsIO(m);
m.setInfinity(MathUtils.Infinity);
int numberErrors = m.readMps(fullPathWithoutExtension);
if (numberErrors != 0)
{
string message = string.Format("Errors occurred when reading the mps file '{0}'.", fileName);
SonnetLog.Default.Error(message);
throw new SonnetException(message);
}
// set objective function offest
// setDblParam(OsiObjOffset,m.objectiveOffset()); // WHAT IS THIS??
model = NewHelper(out variables, m.isInteger, m.columnName, m.rowName,
m.getColLower(), m.getColUpper(), m.getObjectiveName(), m.getObjCoefficients(),
m.getNumCols(), m.getNumRows(), m.getRowSense(), m.getMatrixByRow(), m.getRowLower(), m.getRowUpper());
model.Name = fileNameWithoutExtension;
#endregion
}
else if (extension.Equals(".lp"))
{
#region New Model from .lp file
CoinLpIO m = new CoinLpIO();
log.PassToCoinLpIO(m);
m.setInfinity(MathUtils.Infinity);
// If the original problem is
// a maximization problem, the objective function is immediadtly
// flipped to get a minimization problem.
m.readLp(fileName);
model = NewHelper(out variables, m.isInteger, m.columnName, m.rowName,
m.getColLower(), m.getColUpper(), m.getObjName(), m.getObjCoefficients(),
m.getNumCols(), m.getNumRows(), m.getRowSense(), m.getMatrixByRow(), m.getRowLower(), m.getRowUpper());
model.Name = fileNameWithoutExtension;
#endregion
}
else
{
string message = string.Format("Cannot import file {0} : unknown extension '{1}'.", fileName, extension);
SonnetLog.Default.Error(message);
throw new SonnetException(message);
}
return(model);
}
/// <summary>
/// Creates a new model from the given file. The name of the model will be the filename.
/// </summary>
/// <param name="fileName">The mps or lp file to be imported.</param>
/// <param name="variables">The full array of variables created for this new model.</param>
/// <returns>The new model, or an exception if an error occurred.</returns>
public static Model New(string fileName, out Variable[] variables)
{
string fileNameWithoutExtension = Path.GetFileNameWithoutExtension(fileName);
string extension = Path.GetExtension(fileName).ToLower();
Model model = null;
if (extension.Equals(".mps"))
{
#region New Model from .mps file
string directoryName = Path.GetDirectoryName(fileName);
if (directoryName.Length == 0)
{
directoryName = ".";
}
string fullPathWithoutExtension = Path.Combine(directoryName, fileNameWithoutExtension);
// Previously, CoinMpsIO was used but that doesnt read quad info.
// To read MPS with QUAD info use ClpModel or CoinModel readMps.
// CoinModel we havent Wrapped yet at all, so more work.
// ClpModel (ClpSimplex) doesnt do row Sense needed for here, only lb / ub.
// ClpModel also doesnt save the Objective name.
// OsiClp can create row sense from lb / ub, but OsiClp uses CoinMpsIO, so cannot read Quad from OsiClp
// So we use ClpSimplex to read the file, but use an OsiClp of it for rowsense
ClpSimplex m = new ClpSimplex();
OsiClpSolverInterface osiClp = new OsiClpSolverInterface(m);
log.PassToClpModel(m);
int numberErrors = m.readMps(fileName, true, false);
if (numberErrors != 0)
{
string message = string.Format("Errors occurred when reading the mps file '{0}'.", fileName);
SonnetLog.Default.Error(message);
throw new SonnetException(message);
}
// set objective function offest
// Skip this: setDblParam(OsiObjOffset,m.objectiveOffset())
//ClpModel has ClpObjective which may be an implementatin of ClpQuadObjective.
// This can be found by obj->type() == 2 (QuadCoef)
bool fullQuadraticMatrix = false;
CoinPackedMatrix quadraticObjective = null;
ClpObjective clpObjective = m.objectiveAsObject();
if (clpObjective is ClpQuadraticObjective clpQuadraticObjective)
{
Ensure.IsTrue(clpObjective.type() == 2, $"Quadratic Objective must be type 2 but is {clpObjective.type()}.");
fullQuadraticMatrix = clpQuadraticObjective.fullMatrix();
quadraticObjective = clpQuadraticObjective.quadraticObjective();
}
model = NewHelper(out variables, m.isInteger, m.columnName, m.rowName,
m.getColLower(), m.getColUpper(), "OBJROW", m.getObjCoefficients(),
m.getNumCols(), m.getNumRows(), osiClp.getRowSense(), osiClp.getMatrixByRow(), m.getRowLower(), m.getRowUpper(), fullQuadraticMatrix, quadraticObjective);
model.Name = fileNameWithoutExtension;
#endregion
}
else if (extension.Equals(".lp"))
{
#region New Model from .lp file
CoinLpIO m = new CoinLpIO();
log.PassToCoinLpIO(m);
m.setInfinity(MathUtils.Infinity);
// If the original problem is
// a maximization problem, the objective function is immediadtly
// flipped to get a minimization problem.
m.readLp(fileName);
model = NewHelper(out variables, m.isInteger, m.columnName, m.rowName,
m.getColLower(), m.getColUpper(), m.getObjName(), m.getObjCoefficients(),
m.getNumCols(), m.getNumRows(), m.getRowSense(), m.getMatrixByRow(), m.getRowLower(), m.getRowUpper(), false, null);
model.Name = fileNameWithoutExtension;
#endregion
}
else
{
string message = string.Format("Cannot import file {0} : unknown extension '{1}'.", fileName, extension);
SonnetLog.Default.Error(message);
throw new SonnetException(message);
}
if (model == null)
{
string message = $"An error occured while importing {fileName}. No model created.";
SonnetLog.Default.Error(message);
throw new SonnetException(message);
}
return(model);
}