CoinUtils trunk
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Physically removes empty columns in presolve, and reinserts empty columns in postsolve. More...
#include <CoinPresolveEmpty.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. | |
~drop_empty_cols_action () | |
Static Public Member Functions | |
static const CoinPresolveAction * | presolve (CoinPresolveMatrix *, int *ecols, int necols, const CoinPresolveAction *) |
static const CoinPresolveAction * | presolve (CoinPresolveMatrix *prob, const CoinPresolveAction *next) |
Physically removes empty columns in presolve, and reinserts empty columns in postsolve.
Physical removal of rows and columns should be the last activities performed during presolve. Do them exactly once. The row-major matrix is not maintained by this transform.
To physically drop the columns, CoinPrePostsolveMatrix::mcstrt_ and CoinPrePostsolveMatrix::hincol_ are compressed, along with column bounds, objective, and (if present) the column portions of the solution. This renumbers the columns. drop_empty_cols_action::presolve will reconstruct CoinPresolveMatrix::clink_.
Definition at line 34 of file CoinPresolveEmpty.hpp.
drop_empty_cols_action::~drop_empty_cols_action | ( | ) | [inline] |
Definition at line 68 of file CoinPresolveEmpty.hpp.
const char* drop_empty_cols_action::name | ( | ) | const [inline, virtual] |
A name for debug printing.
It is expected that the name is not stored in the transform itself.
Implements CoinPresolveAction.
Definition at line 56 of file CoinPresolveEmpty.hpp.
static const CoinPresolveAction* drop_empty_cols_action::presolve | ( | CoinPresolveMatrix * | , |
int * | ecols, | ||
int | necols, | ||
const CoinPresolveAction * | |||
) | [static] |
static const CoinPresolveAction* drop_empty_cols_action::presolve | ( | CoinPresolveMatrix * | prob, |
const CoinPresolveAction * | next | ||
) | [static] |
void drop_empty_cols_action::postsolve | ( | CoinPostsolveMatrix * | prob | ) | const [virtual] |
Apply the postsolve transformation for this particular presolve action.
Implements CoinPresolveAction.