CoinUtils  2.10.13
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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:

Public Member Functions

const char * name () const
 A name for debug printing. More...
 
void postsolve (CoinPostsolveMatrix *prob) const
 Apply the postsolve transformation for this particular presolve action. More...
 
virtual ~drop_empty_cols_action ()
 
- Public Member Functions inherited from CoinPresolveAction
 CoinPresolveAction (const CoinPresolveAction *next)
 Construct a postsolve object and add it to the transformation list. More...
 
void setNext (const CoinPresolveAction *nextAction)
 modify next (when building rather than passing) More...
 
virtual ~CoinPresolveAction ()
 Virtual destructor. More...
 

Static Public Member Functions

static const CoinPresolveActionpresolve (CoinPresolveMatrix *, const int *ecols, int necols, const CoinPresolveAction *)
 
static const CoinPresolveActionpresolve (CoinPresolveMatrix *prob, const CoinPresolveAction *next)
 
- Static Public Member Functions inherited from CoinPresolveAction
static void throwCoinError (const char *error, const char *ps_routine)
 Stub routine to throw exceptions. More...
 

Additional Inherited Members

- Public Attributes inherited from CoinPresolveAction
const CoinPresolveActionnext
 The next presolve transformation. More...
 

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

virtual drop_empty_cols_action::~drop_empty_cols_action ( )
inlinevirtual

Definition at line 68 of file CoinPresolveEmpty.hpp.

Member Function Documentation

const char* drop_empty_cols_action::name ( ) const
inlinevirtual

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 ,
const 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: