- Main Page
- Modules
- Namespaces
- Classes
- Files
- Related Pages

- Alphabetical List
- Class List
- Class Hierarchy
- Class Members

# implied_free_action Class Reference

Detect and process implied free variables. More...

`#include <CoinPresolveImpliedFree.hpp>`

Inheritance diagram for implied_free_action:

[legend]
Collaboration diagram for implied_free_action:

[legend]
List of all members.

## 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.
| ~implied_free_action ()
## Static Public Member Functions
static const CoinPresolveAction * | presolve (CoinPresolveMatrix *prob, const CoinPresolveAction *next, int &fillLevel)
## Private Member Functions
| implied_free_action (int nactions, const action *actions, const CoinPresolveAction *next)
## Private Attributes
const int | nactions_
const action *const | actions_
## Classes
struct | action

## Detailed Description

Detect and process implied free variables.

Consider a singleton variable x (i.e., a variable involved in only one constraint). Suppose that the bounds on that constraint, combined with the bounds on the other variables involved in the constraint, are such that even the worst case values of the other variables still imply bounds for x which are tighter than the variable's original bounds. Since x can never reach its upper or lower bounds, it is an implied free variable. Both x and the constraint can be deleted from the problem.

The transform also handles more complicated variations, where x is not a singleton.

Definition at line 27 of file CoinPresolveImpliedFree.hpp.

## Constructor & Destructor Documentation

implied_free_action::implied_free_action | ( | int | nactions,
|  | const action * | actions,
|  | const CoinPresolveAction * | next |
| ) |  |  | `[inline, private]`

Definition at line 40 of file CoinPresolveImpliedFree.hpp.

implied_free_action::~implied_free_action | ( |  | ) |

## Member Function Documentation

const char* implied_free_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* implied_free_action::presolve | ( | CoinPresolveMatrix * | prob,
|  | const CoinPresolveAction * | next,
|  | int & | fillLevel |
| ) |  |  | `[static]`

void implied_free_action::postsolve | ( | CoinPostsolveMatrix * | prob | ) | const`[virtual]`

Apply the postsolve transformation for this particular presolve action.

Implements CoinPresolveAction.

## Member Data Documentation

const int implied_free_action::nactions_`[private]`

Definition at line 37 of file CoinPresolveImpliedFree.hpp.

const action* const implied_free_action::actions_`[private]`

Definition at line 38 of file CoinPresolveImpliedFree.hpp.

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

- /home/coin/SVN-release/DyLP-1.5.0/CoinUtils/src/CoinPresolveImpliedFree.hpp