doubleton_action Class Reference

Solve ax+by=c for y and substitute y out of the problem. More...

#include <CoinPresolveDoubleton.hpp>

Inheritance diagram for doubleton_action:

[legend]Collaboration diagram for doubleton_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.
	~doubleton_action ()
Static Public Member Functions
static const CoinPresolveAction *	presolve (CoinPresolveMatrix *, const CoinPresolveAction *next)
Public Attributes
const int	nactions_
const action *const	actions_
Private Member Functions
	doubleton_action (int nactions, const action *actions, const CoinPresolveAction *next)
Classes
struct	action

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Detailed Description

Solve ax+by=c for y and substitute y out of the problem.

This moves the bounds information for y onto x, making y free and allowing us to substitute it away.

	   a x + b y = c
	   l1 <= x <= u1
	   l2 <= y <= u2	==>
	  
	   l2 <= (c - a x) / b <= u2
	   b/-a > 0 ==> (b l2 - c) / -a <= x <= (b u2 - c) / -a
	   b/-a < 0 ==> (b u2 - c) / -a <= x <= (b l2 - c) / -a
  

Definition at line 24 of file CoinPresolveDoubleton.hpp.

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Constructor & Destructor Documentation

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

Definition at line 52 of file CoinPresolveDoubleton.hpp.

doubleton_action::~doubleton_action

(

)

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Member Function Documentation

const char* doubleton_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 60 of file CoinPresolveDoubleton.hpp.

static const CoinPresolveAction* doubleton_action::presolve	(	CoinPresolveMatrix *	,
		const CoinPresolveAction *	next
	)			[static]

void doubleton_action::postsolve

(

CoinPostsolveMatrix *

prob

)

const [virtual]

Apply the postsolve transformation for this particular presolve action.

Implements CoinPresolveAction.

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Member Data Documentation

const int doubleton_action::nactions_

Definition at line 48 of file CoinPresolveDoubleton.hpp.

const action* const doubleton_action::actions_

Definition at line 49 of file CoinPresolveDoubleton.hpp.

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

• /home/coin/SVN-release/CoinAll-1.1.0/CoinUtils/src/CoinPresolveDoubleton.hpp

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