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drop_empty_cols_action Class Reference

Physically removes empty columns in presolve, and reinserts empty columns in postsolve. More...

#include <CoinPresolveEmpty.hpp>

Inheritance diagram for drop_empty_cols_action:
Collaboration diagram for drop_empty_cols_action:

List of all members.

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 CoinPresolveActionpresolve (CoinPresolveMatrix *, int *ecols, int necols, const CoinPresolveAction *)
static const CoinPresolveActionpresolve (CoinPresolveMatrix *prob, const CoinPresolveAction *next)

Detailed Description

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_.

Todo:
Confirm correct behaviour with solution in presolve.

Definition at line 34 of file CoinPresolveEmpty.hpp.


Constructor & Destructor Documentation

drop_empty_cols_action::~drop_empty_cols_action ( ) [inline]

Definition at line 68 of file CoinPresolveEmpty.hpp.


Member Function Documentation

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.


The documentation for this class was generated from the following file:
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