Scippy

SoPlex

Sequential object-oriented simPlex

(In)equality for LPs. More...

#include <lprowbase.h>

Public Types
Types
enum	Type { LESS_EQUAL , EQUAL , GREATER_EQUAL , RANGE }
	(In)Equality type of an LP row. More...

Public Member Functions
Construction / destruction
	LPRowBase (int defDim=0)
	Constructs LPRowBase with a vector ready to hold `defDim` nonzeros. More...

LPRowBase< R > &	operator= (const LPRowBase< R > &row)
	Assignment operator. More...

	LPRowBase (const LPRowBase< R > &row)
	Copy constructor. More...

template<class S >
	LPRowBase (const LPRowBase< S > &row)
	Copy constructor. More...

	LPRowBase (const R &p_lhs, const SVectorBase< R > &p_rowVector, const R &p_rhs, const R &p_obj=0)
	Constructs LPRowBase with the given left-hand side, right-hand side and rowVector. More...

	LPRowBase (const SVectorBase< R > &p_rowVector, Type p_type, const R &p_value, const R &p_obj=0)
	Constructs LPRowBase from passed `rowVector`, `type` and `value`. More...

	~LPRowBase ()
	Destructor. More...

Access / modification
Type	type () const
	Gets type of row. More...

void	setType (Type p_type)
	Sets type of (in)equality. More...

R	value () const
	Right hand side value of (in)equality. More...

R	lhs () const
	Left-hand side value. More...

void	setLhs (const R &p_left)
	Sets left-hand side value. More...

R	rhs () const
	Right-hand side value. More...

void	setRhs (const R &p_right)
	Sets right-hand side value. More...

R	obj () const
	Objective coefficient value. More...

void	setObj (const R &p_obj)
	Sets objective coefficient value. More...

const SVectorBase< R > &	rowVector () const
	Constraint row vector. More...

void	setRowVector (const DSVectorBase< R > &p_vec)
	access constraint row vector. More...

Consistency check
bool	isConsistent () const
	Checks consistency. More...

Private Attributes
Data
R	left
	left-hand side of the constraint More...

R	right
	right-hand side of the constraint More...

R	object
	objective coefficient of corresponding slack variable s = vec times primal More...

DSVectorBase< R >	vec
	the row vector More...

Friends
template<class S >
class	LPRowBase

Detailed Description

template<class R>
class soplex::LPRowBase< R >

(In)equality for LPs.

Class LPRowBase provides constraints for linear programs in the form

\[ l \le a^Tx \le r, \]

where a is a DSVector. l is referred to as left hand side, r as right hand side and a as row vector or the constraint vector. l and r may also take values \(\pm\) R(infinity). This static member is predefined, but may be overridden to meet the needs of the LP solver to be used.

LPRowBases allow to specify regular inequalities of the form

\[ a^Tx \sim \alpha, \]

where \(\sim\) can take any value of \(\le, =, \ge\), by setting rhs and lhs to the same value or setting one of them to \(\infty\).

Since constraints in the regular form occur often, LPRowBases offers methods type() and value() for retreiving \(\sim\) and \(\alpha\) of an LPRowBase in this form, respectively. Also, a constructor for LPRowBases given in regular form is provided.

Definition at line 54 of file lprowbase.h.

Member Enumeration Documentation

◆ Type

enum Type

(In)Equality type of an LP row.

LPRowBases may be of one of the following Types. This datatype may be used for constructing new LPRowBases in the regular form.

Enumerator
LESS_EQUAL	\(a^Tx \le \alpha\).
EQUAL	\(a^Tx = \alpha\).
GREATER_EQUAL	\(a^Tx \ge \alpha\).
RANGE	\(\lambda \le a^Tx \le \rho\).

Definition at line 81 of file lprowbase.h.

Constructor & Destructor Documentation

◆ LPRowBase() [1/5]

LPRowBase ( int defDim = 0 )

explicit

Constructs LPRowBase with a vector ready to hold defDim nonzeros.

Definition at line 96 of file lprowbase.h.

References LPRowBase< R >::isConsistent().

◆ LPRowBase() [2/5]

LPRowBase ( const LPRowBase< R > & row )

Copy constructor.

Definition at line 117 of file lprowbase.h.

References LPRowBase< R >::isConsistent().

◆ LPRowBase() [3/5]

LPRowBase ( const LPRowBase< S > & row )

Copy constructor.

Definition at line 125 of file lprowbase.h.

References LPRowBase< R >::isConsistent().

◆ LPRowBase() [4/5]

LPRowBase	(	const R &	p_lhs,
		const SVectorBase< R > &	p_rowVector,
		const R &	p_rhs,
		const R &	p_obj = `0`
	)

Constructs LPRowBase with the given left-hand side, right-hand side and rowVector.

Definition at line 132 of file lprowbase.h.

References LPRowBase< R >::isConsistent().

◆ LPRowBase() [5/5]

LPRowBase	(	const SVectorBase< R > &	p_rowVector,
		Type	p_type,
		const R &	p_value,
		const R &	p_obj = `0`
	)

Constructs LPRowBase from passed rowVector, type and value.

Definition at line 139 of file lprowbase.h.

References LPRowBase< R >::EQUAL, LPRowBase< R >::GREATER_EQUAL, soplex::infinity, LPRowBase< R >::isConsistent(), LPRowBase< R >::left, LPRowBase< R >::LESS_EQUAL, and LPRowBase< R >::right.

◆ ~LPRowBase()

~LPRowBase ( )

Destructor.

Definition at line 167 of file lprowbase.h.

Member Function Documentation

◆ isConsistent()

bool isConsistent ( ) const

Checks consistency.

Definition at line 288 of file lprowbase.h.

References LPRowBase< R >::vec.

Referenced by LPRowBase< R >::LPRowBase(), and LPRowBase< R >::operator=().

◆ lhs()

R lhs ( ) const

Left-hand side value.

Definition at line 234 of file lprowbase.h.

References LPRowBase< R >::left.

Referenced by LPRowSetBase< R >::add(), SPxLPBase< R >::changeRow(), LPRowBase< R >::setType(), LPRowBase< R >::type(), and LPRowBase< R >::value().

◆ obj()

R obj ( ) const

Objective coefficient value.

Definition at line 258 of file lprowbase.h.

References LPRowBase< R >::object.

Referenced by LPRowSetBase< R >::add(), and SPxLPBase< R >::changeRow().

◆ operator=()

LPRowBase< R > & operator= ( const LPRowBase< R > & row )

Assignment operator.

Definition at line 103 of file lprowbase.h.

References LPRowBase< R >::isConsistent(), LPRowBase< R >::left, LPRowBase< R >::object, LPRowBase< R >::right, and LPRowBase< R >::vec.

◆ rhs()

R rhs ( ) const

Right-hand side value.

Definition at line 246 of file lprowbase.h.

References LPRowBase< R >::right.

Referenced by LPRowSetBase< R >::add(), SPxLPBase< R >::changeRow(), LPRowBase< R >::setType(), LPRowBase< R >::type(), and LPRowBase< R >::value().

◆ rowVector()

const SVectorBase< R > & rowVector ( ) const

Constraint row vector.

Definition at line 270 of file lprowbase.h.

References LPRowBase< R >::vec.

Referenced by LPRowSetBase< R >::add(), SPxLPBase< R >::changeRow(), and SoPlex_getRowVectorRational().

◆ setLhs()

void setLhs ( const R & p_left )

Sets left-hand side value.

Definition at line 240 of file lprowbase.h.

References LPRowBase< R >::left.

Referenced by SPxLPBase< R >::getRow().

◆ setObj()

void setObj ( const R & p_obj )

Sets objective coefficient value.

Definition at line 264 of file lprowbase.h.

Referenced by SPxLPBase< R >::getRow().

◆ setRhs()

void setRhs ( const R & p_right )

Sets right-hand side value.

Definition at line 252 of file lprowbase.h.

References LPRowBase< R >::right.

Referenced by SPxLPBase< R >::getRow().

◆ setRowVector()

void setRowVector ( const DSVectorBase< R > & p_vec )

access constraint row vector.

Definition at line 276 of file lprowbase.h.

References LPRowBase< R >::vec.

Referenced by SPxLPBase< R >::getRow().

◆ setType()

void setType ( Type p_type )

Sets type of (in)equality.

Definition at line 192 of file lprowbase.h.

References LPRowBase< R >::EQUAL, LPRowBase< R >::GREATER_EQUAL, soplex::infinity, LPRowBase< R >::left, LPRowBase< R >::LESS_EQUAL, LPRowBase< R >::lhs(), LPRowBase< R >::RANGE, LPRowBase< R >::rhs(), LPRowBase< R >::right, and SPX_MSG_ERROR.

◆ type()

Type type ( ) const

Gets type of row.

Definition at line 177 of file lprowbase.h.

References LPRowBase< R >::EQUAL, LPRowBase< R >::GREATER_EQUAL, soplex::infinity, LPRowBase< R >::LESS_EQUAL, LPRowBase< R >::lhs(), LPRowBase< R >::RANGE, and LPRowBase< R >::rhs().

Referenced by LPRowBase< R >::value().

◆ value()

R value ( ) const

Right hand side value of (in)equality.

This method returns \(\alpha\) for a LPRowBase in regular form. However, value() may only be called for LPRowBases with type() != RANGE.

Definition at line 226 of file lprowbase.h.

References soplex::infinity, LPRowBase< R >::lhs(), LPRowBase< R >::RANGE, LPRowBase< R >::rhs(), and LPRowBase< R >::type().

Friends And Related Function Documentation

◆ LPRowBase

friend class LPRowBase

friend

Definition at line 56 of file lprowbase.h.

Member Data Documentation

◆ left

R left

private

left-hand side of the constraint

Definition at line 64 of file lprowbase.h.

Referenced by LPRowBase< R >::lhs(), LPRowBase< R >::LPRowBase(), LPRowBase< R >::operator=(), LPRowBase< R >::setLhs(), and LPRowBase< R >::setType().

◆ object

R object

private

objective coefficient of corresponding slack variable s = vec times primal

Definition at line 66 of file lprowbase.h.

Referenced by LPRowBase< R >::obj(), and LPRowBase< R >::operator=().

◆ right

R right

private

right-hand side of the constraint

Definition at line 65 of file lprowbase.h.

Referenced by LPRowBase< R >::LPRowBase(), LPRowBase< R >::operator=(), LPRowBase< R >::rhs(), LPRowBase< R >::setRhs(), and LPRowBase< R >::setType().

◆ vec

DSVectorBase<R> vec

private

the row vector

Definition at line 67 of file lprowbase.h.

Referenced by LPRowBase< R >::isConsistent(), LPRowBase< R >::operator=(), LPRowBase< R >::rowVector(), and LPRowBase< R >::setRowVector().