#include <CoinPresolveUseless.hpp>
Classes | |
struct | action |
Public Member Functions | |
const char * | name () const |
A name for debug printing. | |
void | postsolve (CoinPostsolveMatrix *prob) const |
Apply the postsolve transformation for this particular presolve action. | |
virtual | ~useless_constraint_action () |
Static Public Member Functions | |
static const CoinPresolveAction * | presolve (CoinPresolveMatrix *prob, const int *useless_rows, int nuseless_rows, const CoinPresolveAction *next) |
Private Member Functions | |
useless_constraint_action (int nactions, const action *actions, const CoinPresolveAction *next) | |
Private Attributes | |
const int | nactions_ |
const action *const | actions_ |
Related Functions | |
(Note that these are not member functions.) | |
const CoinPresolveAction * | testRedundant (CoinPresolveMatrix *prob, const CoinPresolveAction *next) |
Scan constraints looking for useless constraints. |
Definition at line 10 of file CoinPresolveUseless.hpp.
useless_constraint_action::useless_constraint_action | ( | int | nactions, | |
const action * | actions, | |||
const CoinPresolveAction * | next | |||
) | [private] |
virtual useless_constraint_action::~useless_constraint_action | ( | ) | [virtual] |
const char* useless_constraint_action::name | ( | ) | const [virtual] |
A name for debug printing.
It is expected that the name is not stored in the transform itself.
Implements CoinPresolveAction.
static const CoinPresolveAction* useless_constraint_action::presolve | ( | CoinPresolveMatrix * | prob, | |
const int * | useless_rows, | |||
int | nuseless_rows, | |||
const CoinPresolveAction * | next | |||
) | [static] |
void useless_constraint_action::postsolve | ( | CoinPostsolveMatrix * | prob | ) | const [virtual] |
Apply the postsolve transformation for this particular presolve action.
Implements CoinPresolveAction.
const CoinPresolveAction * testRedundant | ( | CoinPresolveMatrix * | prob, | |
const CoinPresolveAction * | next | |||
) | [related] |
Scan constraints looking for useless constraints.
A front end to identify useless constraints and hand them to useless_constraint_action::presolve() for processing.
In a bit more detail, the routine implements a greedy algorithm that identifies a set of necessary constraints. A constraint is necessary if it implies a tighter bound on a variable than the original column bound. These tighter column bounds are then used to calculate row activity and identify constraints that are useless given the presence of the necessary constraints.
const int useless_constraint_action::nactions_ [private] |
Definition at line 20 of file CoinPresolveUseless.hpp.
const action* const useless_constraint_action::actions_ [private] |
Definition at line 21 of file CoinPresolveUseless.hpp.