This class is an abstract base class for MIP solvers. This class provides a full interface for set and modify an MIP problem, solve it and retrieve the solution. You can use one of the descendants as a concrete implementation, or the Lp
default MIP solver. However, if you would like to handle MIP solvers as reference or pointer in a generic way, you can use this class directly.
#include <lemon/lp_base.h>
Set Column Type | |
enum | ColTypes { REAL = 0, INTEGER = 1 } |
Possible variable (column) types (e.g. real, integer, binary etc.) More... | |
void | colType (Col c, ColTypes col_type) |
ColTypes | colType (Col c) const |
Public Types | |
enum | ProblemType { UNDEFINED = 0, INFEASIBLE = 1, FEASIBLE = 2, OPTIMAL = 3, UNBOUNDED = 4 } |
The problem types for MIP problems. More... | |
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enum | SolveExitStatus { SOLVED = 0, UNSOLVED = 1 } |
Possible outcomes of an LP solving procedure. More... | |
enum | Sense { MIN, MAX } |
Direction of the optimization. More... | |
enum | MessageLevel { MESSAGE_NOTHING, MESSAGE_ERROR, MESSAGE_WARNING, MESSAGE_NORMAL, MESSAGE_VERBOSE } |
Enum for messageLevel() parameter. More... | |
typedef double | Value |
The floating point type used by the solver. | |
Public Member Functions | |
virtual MipSolver * | newSolver () const =0 |
Allocate a new MIP problem instance. | |
virtual MipSolver * | cloneSolver () const =0 |
Make a copy of the MIP problem. | |
Solve the MIP | |
SolveExitStatus | solve () |
Obtain the Solution | |
ProblemType | type () const |
The type of the MIP problem. | |
Value | sol (Col c) const |
Return the value of the row in the solution. | |
Value | sol (const Expr &e) const |
Return the value of the expression in the solution. | |
Value | solValue () const |
The value of the objective function. | |
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virtual | ~LpBase () |
Virtual destructor. | |
const char * | solverName () const |
Gives back the name of the solver. | |
Col | addCol () |
Add a new empty column (i.e a new variable) to the LP. | |
template<class T > | |
int | addColSet (T &t) |
Adds several new columns (i.e variables) at once. | |
void | col (Col c, const DualExpr &e) |
Set a column (i.e a dual constraint) of the LP. | |
DualExpr | col (Col c) const |
Get a column (i.e a dual constraint) of the LP. | |
Col | addCol (const DualExpr &e, Value o=0) |
Add a new column to the LP. | |
Row | addRow () |
Add a new empty row (i.e a new constraint) to the LP. | |
template<class T > | |
int | addRowSet (T &t) |
Add several new rows (i.e constraints) at once. | |
void | row (Row r, Value l, const Expr &e, Value u) |
Set a row (i.e a constraint) of the LP. | |
void | row (Row r, const Constr &c) |
Set a row (i.e a constraint) of the LP. | |
Expr | row (Row r) const |
Get a row (i.e a constraint) of the LP. | |
Row | addRow (Value l, const Expr &e, Value u) |
Add a new row (i.e a new constraint) to the LP. | |
Row | addRow (const Constr &c) |
Add a new row (i.e a new constraint) to the LP. | |
void | erase (Col c) |
Erase a column (i.e a variable) from the LP. | |
void | erase (Row r) |
Erase a row (i.e a constraint) from the LP. | |
std::string | colName (Col c) const |
Get the name of a column. | |
void | colName (Col c, const std::string &name) |
Set the name of a column. | |
Col | colByName (const std::string &name) const |
Get the column by its name. | |
std::string | rowName (Row r) const |
Get the name of a row. | |
void | rowName (Row r, const std::string &name) |
Set the name of a row. | |
Row | rowByName (const std::string &name) const |
Get the row by its name. | |
void | coeff (Row r, Col c, Value val) |
Set an element of the coefficient matrix of the LP. | |
Value | coeff (Row r, Col c) const |
Get an element of the coefficient matrix of the LP. | |
void | colLowerBound (Col c, Value value) |
Set the lower bound of a column (i.e a variable) | |
Value | colLowerBound (Col c) const |
Get the lower bound of a column (i.e a variable) | |
template<class T > | |
void | colLowerBound (T &t, Value value) |
Set the lower bound of several columns (i.e variables) at once. | |
void | colUpperBound (Col c, Value value) |
Set the upper bound of a column (i.e a variable) | |
Value | colUpperBound (Col c) const |
Get the upper bound of a column (i.e a variable) | |
template<class T > | |
void | colUpperBound (T &t, Value value) |
Set the upper bound of several columns (i.e variables) at once. | |
void | colBounds (Col c, Value lower, Value upper) |
Set the lower and the upper bounds of a column (i.e a variable) | |
template<class T > | |
void | colBounds (T &t, Value lower, Value upper) |
Set the lower and the upper bound of several columns (i.e variables) at once. | |
void | rowLowerBound (Row r, Value value) |
Set the lower bound of a row (i.e a constraint) | |
Value | rowLowerBound (Row r) const |
Get the lower bound of a row (i.e a constraint) | |
void | rowUpperBound (Row r, Value value) |
Set the upper bound of a row (i.e a constraint) | |
Value | rowUpperBound (Row r) const |
Get the upper bound of a row (i.e a constraint) | |
void | objCoeff (Col c, Value v) |
Set an element of the objective function. | |
Value | objCoeff (Col c) const |
Get an element of the objective function. | |
void | obj (const Expr &e) |
Set the objective function. | |
Expr | obj () const |
Get the objective function. | |
void | sense (Sense sense) |
Set the direction of optimization. | |
Sense | sense () const |
Query the direction of the optimization. | |
void | max () |
Set the sense to maximization. | |
void | min () |
Set the sense to maximization. | |
void | clear () |
Clears the problem. | |
void | messageLevel (MessageLevel level) |
Sets the message level of the solver. | |
Additional Inherited Members | |
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static int | id (const Col &col) |
Returns the ID of the column. | |
static Col | colFromId (int id) |
Returns the column with the given ID. | |
static int | id (const Row &row) |
Returns the ID of the row. | |
static Row | rowFromId (int id) |
Returns the row with the given ID. | |
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static const Value | INF |
The infinity constant. | |
static const Value | NaN |
The not a number constant. | |
enum ProblemType |
enum ColTypes |
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inline |
Solve the MIP problem at hand
Sets the type of the given column to the given type.
Return the value of the row in the solution.
Return the value of the expression in the solution, i.e. the dot product of the solution and the expression.