LPWrapper Class Reference

#include <OpenMS/DATASTRUCTURES/LPWrapper.h>

Classes
struct	SolverParam
	Struct that holds the parameters of the LP solver. More...

Public Types
enum	Type {   UNBOUNDED = 1, LOWER_BOUND_ONLY, UPPER_BOUND_ONLY, DOUBLE_BOUNDED,   FIXED }
enum	VariableType { CONTINUOUS = 1, INTEGER, BINARY }
enum	Sense { MIN = 1, MAX }
enum	WriteFormat { FORMAT_LP = 0, FORMAT_MPS, FORMAT_GLPK }
enum	SOLVER { SOLVER_GLPK = 0 }
enum	SolverStatus { UNDEFINED = 1, OPTIMAL = 5, FEASIBLE = 2, NO_FEASIBLE_SOL = 4 }

Public Member Functions
	LPWrapper ()
virtual	~LPWrapper ()
Int	addRow (std::vector< Int > row_indices, std::vector< double > row_values, const String &name)
	adds a row to the LP matrix, returns index More...
Int	addColumn ()
	adds an empty column to the LP matrix, returns index More...
Int	addColumn (std::vector< Int > column_indices, std::vector< double > column_values, const String &name)
	adds a column to the LP matrix, returns index More...
Int	addRow (std::vector< Int > &row_indices, std::vector< double > &row_values, const String &name, double lower_bound, double upper_bound, Type type)
	Adds a row with boundaries to the LP matrix, returns index. More...
Int	addColumn (std::vector< Int > &column_indices, std::vector< double > &column_values, const String &name, double lower_bound, double upper_bound, Type type)
	Adds a column with boundaries to the LP matrix, returns index. More...
void	deleteRow (Int index)
	delete index-th row More...
void	setColumnName (Int index, const String &name)
	sets name of the index-th column More...
String	getColumnName (Int index)
	gets name of the index-th column More...
String	getRowName (Int index)
	sets name of the index-th row More...
Int	getRowIndex (const String &name)
	gets index of the row with name More...
Int	getColumnIndex (const String &name)
	gets index of the column with name More...
double	getColumnUpperBound (Int index)
	gets column's upper bound More...
double	getColumnLowerBound (Int index)
	gets column's lower bound More...
double	getRowUpperBound (Int index)
	gets row's upper bound More...
double	getRowLowerBound (Int index)
	gets row's lower bound More...
void	setRowName (Int index, const String &name)
	sets name of the index-th row More...
void	setColumnBounds (Int index, double lower_bound, double upper_bound, Type type)
	Set column bounds. More...
void	setRowBounds (Int index, double lower_bound, double upper_bound, Type type)
	Set row bounds. More...
void	setColumnType (Int index, VariableType type)
	Set column/variable type. More...
VariableType	getColumnType (Int index)
	Get column/variable type. More...
void	setObjective (Int index, double obj_value)
	set objective value for column with index More...
double	getObjective (Int index)
	get objective value for column with index More...
void	setObjectiveSense (Sense sense)
	Set objective direction. More...
Sense	getObjectiveSense ()
Int	getNumberOfColumns ()
	get number of columns More...
Int	getNumberOfRows ()
	get number of rows More...
void	setElement (Int row_index, Int column_index, double value)
double	getElement (Int row_index, Int column_index)
void	readProblem (String filename, String format)
	Read LP from file. More...
void	writeProblem (const String &filename, const WriteFormat format) const
	Write LP formulation to a file. More...
Int	solve (SolverParam &solver_param, const Size verbose_level=0)
	solve problems, parameters like enabled heuristics can be given via solver_param More...
SolverStatus	getStatus ()
	Get solution status. More...
double	getObjectiveValue ()
double	getColumnValue (Int index)
Int	getNumberOfNonZeroEntriesInRow (Int idx)
void	getMatrixRow (Int idx, std::vector< Int > &indexes)
void	setSolver (const SOLVER s)
SOLVER	getSolver () const
	get currently active solver More...

Protected Attributes
glp_prob *	lp_problem_
SOLVER	solver_

Member Enumeration Documentation

Sense

enum Sense

Enumerator
MIN
MAX

SOLVER

enum SOLVER

Enumerator
SOLVER_GLPK

SolverStatus

enum SolverStatus

Enumerator
UNDEFINED
OPTIMAL
FEASIBLE
NO_FEASIBLE_SOL

Type

enum Type

Enumerator
UNBOUNDED
LOWER_BOUND_ONLY
UPPER_BOUND_ONLY
DOUBLE_BOUNDED
FIXED

VariableType

enum VariableType

Enumerator
CONTINUOUS
INTEGER
BINARY

WriteFormat

enum WriteFormat

Enumerator
FORMAT_LP
FORMAT_MPS
FORMAT_GLPK

Constructor & Destructor Documentation

LPWrapper()

LPWrapper

(

)

~LPWrapper()

virtual ~LPWrapper ( )

virtual

Member Function Documentation

addColumn() [1/3]

Int addColumn

(

)

adds an empty column to the LP matrix, returns index

addColumn() [2/3]

Int addColumn	(	std::vector< Int >	column_indices,
		std::vector< double >	column_values,
		const String &	name
	)

adds a column to the LP matrix, returns index

addColumn() [3/3]

Int addColumn	(	std::vector< Int > &	column_indices,
		std::vector< double > &	column_values,
		const String &	name,
		double	lower_bound,
		double	upper_bound,
		Type	type
	)

Adds a column with boundaries to the LP matrix, returns index.

Parameters

column_indices
column_values
name
lower_bound
upper_bound
type	1 - unbounded, 2 - only lower bound, 3 - only upper bound, 4 - double-bounded variable, 5 - fixed variable

addRow() [1/2]

Int addRow	(	std::vector< Int >	row_indices,
		std::vector< double >	row_values,
		const String &	name
	)

adds a row to the LP matrix, returns index

addRow() [2/2]

Int addRow	(	std::vector< Int > &	row_indices,
		std::vector< double > &	row_values,
		const String &	name,
		double	lower_bound,
		double	upper_bound,
		Type	type
	)

Adds a row with boundaries to the LP matrix, returns index.

If you have a fixed variable, GLPK requires to use the "fixed" type, instead of "double-bounded" with equal bounds.

Parameters

row_indices
row_values
name
lower_bound
upper_bound
type	Type of the row 1 - unbounded, 2 - only lower bound, 3 - only upper bound, 4 - double-bounded variable, 5 - fixed variable

deleteRow()

void deleteRow

(

Int

index

)

delete index-th row

getColumnIndex()

Int getColumnIndex

(

const String &

name

)

gets index of the column with name

getColumnLowerBound()

double getColumnLowerBound

(

Int

index

)

gets column's lower bound

getColumnName()

String getColumnName

(

Int

index

)

gets name of the index-th column

getColumnType()

VariableType getColumnType

(

Int

index

)

Get column/variable type.

Parameters

index

Returns

1- continuous, 2- integer, 3- binary variable

getColumnUpperBound()

double getColumnUpperBound

(

Int

index

)

gets column's upper bound

getColumnValue()

double getColumnValue

(

Int

index

)

getElement()

double getElement	(	Int	row_index,
		Int	column_index
	)

getMatrixRow()

void getMatrixRow	(	Int	idx,
		std::vector< Int > &	indexes
	)

getNumberOfColumns()

Int getNumberOfColumns

(

)

get number of columns

getNumberOfNonZeroEntriesInRow()

Int getNumberOfNonZeroEntriesInRow

(

Int

idx

)

getNumberOfRows()

Int getNumberOfRows

(

)

get number of rows

getObjective()

double getObjective

(

Int

index

)

get objective value for column with index

getObjectiveSense()

Sense getObjectiveSense

(

)

getObjectiveValue()

double getObjectiveValue

(

)

getRowIndex()

Int getRowIndex

(

const String &

name

)

gets index of the row with name

getRowLowerBound()

double getRowLowerBound

(

Int

index

)

gets row's lower bound

getRowName()

String getRowName

(

Int

index

)

sets name of the index-th row

getRowUpperBound()

double getRowUpperBound

(

Int

index

)

gets row's upper bound

getSolver()

SOLVER getSolver

(

)

const

get currently active solver

getStatus()

SolverStatus getStatus

(

)

Get solution status.

Returns

status: 1 - undefined, 2 - integer optimal, 3- integer feasible (no optimality proven), 4- no integer feasible solution

readProblem()

void readProblem	(	String	filename,
		String	format
	)

Read LP from file.

Parameters

filename	Filename where to store the LP problem.
format	LP, MPS or GLPK.

setColumnBounds()

void setColumnBounds	(	Int	index,
		double	lower_bound,
		double	upper_bound,
		Type	type
	)

Set column bounds.

Parameters

index
lower_bound
upper_bound
type	1 - unbounded, 2 - only lower bound, 3 - only upper bound, 4 - double-bounded variable, 5 - fixed variable

setColumnName()

void setColumnName	(	Int	index,
		const String &	name
	)

sets name of the index-th column

setColumnType()

void setColumnType	(	Int	index,
		VariableType	type
	)

Set column/variable type.

Parameters

index
type	1- continuous, 2- integer, 3- binary variable

setElement()

void setElement	(	Int	row_index,
		Int	column_index,
		double	value
	)

setObjective()

void setObjective	(	Int	index,
		double	obj_value
	)

set objective value for column with index

setObjectiveSense()

void setObjectiveSense

(

Sense

sense

)

Set objective direction.

Parameters

sense

1- minimize, 2- maximize

setRowBounds()

void setRowBounds	(	Int	index,
		double	lower_bound,
		double	upper_bound,
		Type	type
	)

Set row bounds.

Parameters

index
lower_bound
upper_bound
type	1 - unbounded, 2 - only lower bound, 3 - only upper bound, 4 - double-bounded variable, 5 - fixed constraint

setRowName()

void setRowName	(	Int	index,
		const String &	name
	)

sets name of the index-th row

setSolver()

void setSolver

(

const SOLVER

s

)

choose solver; by default, only GLPK is available set this only at the very beginning of building your model, as otherwise your model is incomplete

solve()

Int solve	(	SolverParam &	solver_param,
		const Size	verbose_level = 0
	)

solve problems, parameters like enabled heuristics can be given via solver_param

The verbose level (0,1,2) determines if the solver prints status messages and internals.

Parameters

solver_param
verbose_level

Returns

solver dependent (todo: fix)

writeProblem()

void writeProblem	(	const String &	filename,
		const WriteFormat	format
	)		const

Write LP formulation to a file.

Parameters

filename	output filename, if the filename ends with '.gz' it will be compressed
format	MPS-format is supported by GLPK and COIN-OR; LP and GLPK-formats only by GLPK

Member Data Documentation

lp_problem_

glp_prob* lp_problem_

protected

solver_

SOLVER solver_

protected