Class MILPSolverCPX

Inheritance Relationships

Base Type

Class Documentation

class MILPSolverCPX : public MILPSolver

Public Functions

MILPSolverCPX()
virtual ~MILPSolverCPX()
virtual MILPSolver *clone()
virtual double getInfinity()
virtual int getNumCols()
virtual int getNumRows()
virtual void setColName(const int &var, const string &asString)
virtual string getColName(const int &var)
virtual void setRowName(const int &cons, const string &asString)
virtual string getRowName(const int &cons)
virtual double getColUpper(const int &var)
virtual void setColUpper(const int &var, const double &b)
virtual double getColLower(const int &var)
virtual void setColLower(const int &var, const double &b)
virtual void setColBounds(const int &var, const double &lb, const double &ub)
virtual bool isColumnInteger(const int &col)

Ascertain whether the given column is an integer.

Parameters:

c – A column index

Returns:

true if column c is an integer.

virtual bool isColumnBinary(const int &col)

Ascertain whether the given column is binary (i.e. a [0,1] integer).

Parameters:

c – A column index

Returns:

true if column c is binary.

virtual double getRowUpper(const int &var)
virtual void setRowUpper(const int &c, const double &b)
virtual double getRowLower(const int &var)
virtual void setRowLower(const int &c, const double &b)
virtual void addCol(const vector<pair<int, double>> &entries, const double &lb, const double &ub, const ColumnType &type)

Functions for the columns (variables) of the model.

virtual void addRow(const vector<pair<int, double>> &entries, const double &lb, const double &ub)

Functions for the rows (constraints) of the model.

virtual void setMaximiseObjective(const bool &maxim)

Objective function calls.

Specify that the calls to solve() should maximise the given objective, rather than minimising.

Parameters:

maxim – If true, the objective will be maximised.

virtual void clearObjective()

Clear the objective coefficients (set each to 0).

virtual void setObjective(double *const entries)

Set the objective function according to the vector of weights given.

Parameters:

entries – An array, size equal to getNumCols() containing the linear coefficient for each column, to use in the objective.

virtual void setObjCoeff(const int &var, const double &w)

Set the linear coefficient in the objective function of the given column.

Parameters:

  • var – The column whose coefficient is to be changed

  • w – The coefficient for column <codevar

virtual void writeLp(const string &filename)

Miscellaneous functions.

virtual bool solve(const bool &skipPresolve)

Solving, and accessing solutions.

virtual const double *getSolution()
virtual const double *getSolutionRows()

Obtain the value of the row in the solution.

Returns:

An array containing getNumRows() values, one for each row.

virtual const double *getPartialSolution(const int &from, const int &to)

Obtain the solution values of a subset of the columns in the LP.

Parameters:

  • from – The start column index of the range to return (inclusive)

  • to – The end column index of the range to return (exclusive)

Returns:

A pointer to an array, where index 0 contains the value of the variable from etc.

virtual double getSingleSolutionVariableValue(const int &col)

Obtain the solution values of the specified variable.

Parameters:

col – The index of the variable (column)

Returns:

The value that variable takes in the most recent solution to the LP

virtual double getObjValue()

Return the computed value of the objective function.

virtual bool supportsQuadratic() const
virtual void getRow(const int &i, vector<pair<int, double>> &entries)

Get a row from the LP, returning the coefficients it contains.

Parameters:

  • i – The index of the row to get

  • entries – A reference to a vector of int,double pairs which, after calling the method, will contain the column indices and coefficients of row i of the LP.

virtual void hush()

Suppress all output from the solver