Detailed Description

interface methods for specific LP solvers

Author: Tobias Achterberg; Marc Pfetsch

This file specifies a generic LP solver interface used by SCIP to create, modify, and solve linear programs of the form

min/max obj * x lhs <= A * x <= rhs lb <= x <= ub

and query information about the solution. Although it includes a few SCIP header files, e.g., because it uses SCIP's return codes, it can be used independently of any SCIP instance.

In the methods accessing information about the (inverse of the) basis matrix, the interface assumes the following column-oriented format: slack variables of rows have coefficient +1 and the basis matrix is a regular m times m submatrix of (A,I), where m is the number of rows and I is the identity matrix. This means that if, internally, the LP solver uses coefficients -1 for some of the slack variables, then rows associated with slacks variables whose coefficient is -1 should be negated in order to return the result in terms of the LP interface definition.

Definition in file lpi.h.

#include "scip/def.h"
#include "blockmemshell/memory.h"
#include "scip/type_retcode.h"
#include "lpi/type_lpi.h"

Go to the source code of this file.

Functions
Miscellaneous Methods
const char *	SCIPlpiGetSolverName (void)

const char *	SCIPlpiGetSolverDesc (void)

void *	SCIPlpiGetSolverPointer (SCIP_LPI *lpi)

LPI Creation and Destruction Methods
SCIP_RETCODE	SCIPlpiCreate (SCIP_LPI *lpi, SCIP_MESSAGEHDLR messagehdlr, const char *name, SCIP_OBJSEN objsen)

SCIP_RETCODE	SCIPlpiFree (SCIP_LPI **lpi)

Modification Methods
SCIP_RETCODE	SCIPlpiLoadColLP (SCIP_LPI lpi, SCIP_OBJSEN objsen, int ncols, const SCIP_Real obj, const SCIP_Real lb, const SCIP_Real ub, char *colnames, int nrows, const SCIP_Real lhs, const SCIP_Real rhs, char rownames, int nnonz, const int beg, const int ind, const SCIP_Real val)

SCIP_RETCODE	SCIPlpiAddCols (SCIP_LPI lpi, int ncols, const SCIP_Real obj, const SCIP_Real lb, const SCIP_Real ub, char *colnames, int nnonz, const int beg, const int ind, const SCIP_Real val)

SCIP_RETCODE	SCIPlpiDelCols (SCIP_LPI *lpi, int firstcol, int lastcol)

SCIP_RETCODE	SCIPlpiDelColset (SCIP_LPI lpi, int dstat)

SCIP_RETCODE	SCIPlpiAddRows (SCIP_LPI lpi, int nrows, const SCIP_Real lhs, const SCIP_Real rhs, char rownames, int nnonz, const int beg, const int ind, const SCIP_Real val)

SCIP_RETCODE	SCIPlpiDelRows (SCIP_LPI *lpi, int firstrow, int lastrow)

SCIP_RETCODE	SCIPlpiDelRowset (SCIP_LPI lpi, int dstat)

SCIP_RETCODE	SCIPlpiClear (SCIP_LPI *lpi)

SCIP_RETCODE	SCIPlpiChgBounds (SCIP_LPI lpi, int ncols, const int ind, const SCIP_Real lb, const SCIP_Real ub)

SCIP_RETCODE	SCIPlpiChgSides (SCIP_LPI lpi, int nrows, const int ind, const SCIP_Real lhs, const SCIP_Real rhs)

SCIP_RETCODE	SCIPlpiChgCoef (SCIP_LPI *lpi, int row, int col, SCIP_Real newval)

SCIP_RETCODE	SCIPlpiChgObjsen (SCIP_LPI *lpi, SCIP_OBJSEN objsen)

SCIP_RETCODE	SCIPlpiChgObj (SCIP_LPI lpi, int ncols, int ind, SCIP_Real *obj)

SCIP_RETCODE	SCIPlpiScaleRow (SCIP_LPI *lpi, int row, SCIP_Real scaleval)

SCIP_RETCODE	SCIPlpiScaleCol (SCIP_LPI *lpi, int col, SCIP_Real scaleval)

Data Accessing Methods
SCIP_RETCODE	SCIPlpiGetNRows (SCIP_LPI lpi, int nrows)

SCIP_RETCODE	SCIPlpiGetNCols (SCIP_LPI lpi, int ncols)

SCIP_RETCODE	SCIPlpiGetObjsen (SCIP_LPI lpi, SCIP_OBJSEN objsen)

SCIP_RETCODE	SCIPlpiGetNNonz (SCIP_LPI lpi, int nnonz)

SCIP_RETCODE	SCIPlpiGetCols (SCIP_LPI lpi, int firstcol, int lastcol, SCIP_Real lb, SCIP_Real ub, int nnonz, int beg, int ind, SCIP_Real *val)

SCIP_RETCODE	SCIPlpiGetRows (SCIP_LPI lpi, int firstrow, int lastrow, SCIP_Real lhs, SCIP_Real rhs, int nnonz, int beg, int ind, SCIP_Real *val)

SCIP_RETCODE	SCIPlpiGetColNames (SCIP_LPI lpi, int firstcol, int lastcol, char colnames, char namestorage, int namestoragesize, int *storageleft)

SCIP_RETCODE	SCIPlpiGetRowNames (SCIP_LPI lpi, int firstrow, int lastrow, char rownames, char namestorage, int namestoragesize, int *storageleft)

SCIP_RETCODE	SCIPlpiGetObj (SCIP_LPI lpi, int firstcol, int lastcol, SCIP_Real vals)

SCIP_RETCODE	SCIPlpiGetBounds (SCIP_LPI lpi, int firstcol, int lastcol, SCIP_Real lbs, SCIP_Real *ubs)

SCIP_RETCODE	SCIPlpiGetSides (SCIP_LPI lpi, int firstrow, int lastrow, SCIP_Real lhss, SCIP_Real *rhss)

SCIP_RETCODE	SCIPlpiGetCoef (SCIP_LPI lpi, int row, int col, SCIP_Real val)

Solving Methods
SCIP_RETCODE	SCIPlpiSolvePrimal (SCIP_LPI *lpi)

SCIP_RETCODE	SCIPlpiSolveDual (SCIP_LPI *lpi)

SCIP_RETCODE	SCIPlpiSolveBarrier (SCIP_LPI *lpi, SCIP_Bool crossover)

SCIP_RETCODE	SCIPlpiStartStrongbranch (SCIP_LPI *lpi)

SCIP_RETCODE	SCIPlpiEndStrongbranch (SCIP_LPI *lpi)

SCIP_RETCODE	SCIPlpiStrongbranchFrac (SCIP_LPI lpi, int col, SCIP_Real psol, int itlim, SCIP_Real down, SCIP_Real up, SCIP_Bool downvalid, SCIP_Bool upvalid, int iter)

SCIP_RETCODE	SCIPlpiStrongbranchesFrac (SCIP_LPI lpi, int cols, int ncols, SCIP_Real psols, int itlim, SCIP_Real down, SCIP_Real up, SCIP_Bool downvalid, SCIP_Bool upvalid, int iter)

SCIP_RETCODE	SCIPlpiStrongbranchInt (SCIP_LPI lpi, int col, SCIP_Real psol, int itlim, SCIP_Real down, SCIP_Real up, SCIP_Bool downvalid, SCIP_Bool upvalid, int iter)

SCIP_RETCODE	SCIPlpiStrongbranchesInt (SCIP_LPI lpi, int cols, int ncols, SCIP_Real psols, int itlim, SCIP_Real down, SCIP_Real up, SCIP_Bool downvalid, SCIP_Bool upvalid, int iter)

Solution Information Methods
SCIP_Bool	SCIPlpiWasSolved (SCIP_LPI *lpi)

SCIP_RETCODE	SCIPlpiGetSolFeasibility (SCIP_LPI lpi, SCIP_Bool primalfeasible, SCIP_Bool *dualfeasible)

SCIP_Bool	SCIPlpiExistsPrimalRay (SCIP_LPI *lpi)

SCIP_Bool	SCIPlpiHasPrimalRay (SCIP_LPI *lpi)

SCIP_Bool	SCIPlpiIsPrimalUnbounded (SCIP_LPI *lpi)

SCIP_Bool	SCIPlpiIsPrimalInfeasible (SCIP_LPI *lpi)

SCIP_Bool	SCIPlpiIsPrimalFeasible (SCIP_LPI *lpi)

SCIP_Bool	SCIPlpiExistsDualRay (SCIP_LPI *lpi)

SCIP_Bool	SCIPlpiHasDualRay (SCIP_LPI *lpi)

SCIP_Bool	SCIPlpiIsDualUnbounded (SCIP_LPI *lpi)

SCIP_Bool	SCIPlpiIsDualInfeasible (SCIP_LPI *lpi)

SCIP_Bool	SCIPlpiIsDualFeasible (SCIP_LPI *lpi)

SCIP_Bool	SCIPlpiIsOptimal (SCIP_LPI *lpi)

SCIP_Bool	SCIPlpiIsStable (SCIP_LPI *lpi)

SCIP_Bool	SCIPlpiIsObjlimExc (SCIP_LPI *lpi)

SCIP_Bool	SCIPlpiIsIterlimExc (SCIP_LPI *lpi)

SCIP_Bool	SCIPlpiIsTimelimExc (SCIP_LPI *lpi)

int	SCIPlpiGetInternalStatus (SCIP_LPI *lpi)

SCIP_RETCODE	SCIPlpiIgnoreInstability (SCIP_LPI lpi, SCIP_Bool success)

SCIP_RETCODE	SCIPlpiGetObjval (SCIP_LPI lpi, SCIP_Real objval)

SCIP_RETCODE	SCIPlpiGetSol (SCIP_LPI lpi, SCIP_Real objval, SCIP_Real primsol, SCIP_Real dualsol, SCIP_Real activity, SCIP_Real redcost)

SCIP_RETCODE	SCIPlpiGetPrimalRay (SCIP_LPI lpi, SCIP_Real ray)

SCIP_RETCODE	SCIPlpiGetDualfarkas (SCIP_LPI lpi, SCIP_Real dualfarkas)

SCIP_RETCODE	SCIPlpiGetIterations (SCIP_LPI lpi, int iterations)

SCIP_RETCODE	SCIPlpiGetRealSolQuality (SCIP_LPI lpi, SCIP_LPSOLQUALITY qualityindicator, SCIP_Real quality)

LP Basis Methods
SCIP_RETCODE	SCIPlpiGetBase (SCIP_LPI lpi, int cstat, int *rstat)

SCIP_RETCODE	SCIPlpiSetBase (SCIP_LPI lpi, int cstat, int *rstat)

SCIP_RETCODE	SCIPlpiGetBasisInd (SCIP_LPI lpi, int bind)

SCIP_RETCODE	SCIPlpiGetBInvRow (SCIP_LPI lpi, int r, SCIP_Real coef, int inds, int ninds)

SCIP_RETCODE	SCIPlpiGetBInvCol (SCIP_LPI lpi, int c, SCIP_Real coef, int inds, int ninds)

SCIP_RETCODE	SCIPlpiGetBInvARow (SCIP_LPI lpi, int r, const SCIP_Real binvrow, SCIP_Real coef, int inds, int *ninds)

SCIP_RETCODE	SCIPlpiGetBInvACol (SCIP_LPI lpi, int c, SCIP_Real coef, int inds, int ninds)

LPi State Methods
SCIP_RETCODE	SCIPlpiGetState (SCIP_LPI lpi, BMS_BLKMEM blkmem, SCIP_LPISTATE **lpistate)

SCIP_RETCODE	SCIPlpiSetState (SCIP_LPI lpi, BMS_BLKMEM blkmem, SCIP_LPISTATE *lpistate)

SCIP_RETCODE	SCIPlpiClearState (SCIP_LPI *lpi)

SCIP_RETCODE	SCIPlpiFreeState (SCIP_LPI lpi, BMS_BLKMEM blkmem, SCIP_LPISTATE **lpistate)

SCIP_Bool	SCIPlpiHasStateBasis (SCIP_LPI lpi, SCIP_LPISTATE lpistate)

SCIP_RETCODE	SCIPlpiReadState (SCIP_LPI lpi, const char fname)

SCIP_RETCODE	SCIPlpiWriteState (SCIP_LPI lpi, const char fname)

LPi Pricing Norms Methods
SCIP_RETCODE	SCIPlpiGetNorms (SCIP_LPI lpi, BMS_BLKMEM blkmem, SCIP_LPINORMS **lpinorms)

SCIP_RETCODE	SCIPlpiSetNorms (SCIP_LPI lpi, BMS_BLKMEM blkmem, SCIP_LPINORMS *lpinorms)

SCIP_RETCODE	SCIPlpiFreeNorms (SCIP_LPI lpi, BMS_BLKMEM blkmem, SCIP_LPINORMS **lpinorms)

Parameter Methods
SCIP_RETCODE	SCIPlpiGetIntpar (SCIP_LPI lpi, SCIP_LPPARAM type, int ival)

SCIP_RETCODE	SCIPlpiSetIntpar (SCIP_LPI *lpi, SCIP_LPPARAM type, int ival)

SCIP_RETCODE	SCIPlpiGetRealpar (SCIP_LPI lpi, SCIP_LPPARAM type, SCIP_Real dval)

SCIP_RETCODE	SCIPlpiSetRealpar (SCIP_LPI *lpi, SCIP_LPPARAM type, SCIP_Real dval)

Numerical Methods
SCIP_Real	SCIPlpiInfinity (SCIP_LPI *lpi)

SCIP_Bool	SCIPlpiIsInfinity (SCIP_LPI *lpi, SCIP_Real val)

File Interface Methods
SCIP_RETCODE	SCIPlpiReadLP (SCIP_LPI lpi, const char fname)

SCIP_RETCODE	SCIPlpiWriteLP (SCIP_LPI lpi, const char fname)

Function Documentation

const char* SCIPlpiGetSolverName ( void )

gets name and version of LP solver

Definition at line 433 of file lpi_clp.cpp.

References CLP_VERSION, CPX_SUBVERSION, LPINAME, SCIP_Real, SCIPdebugMessage, and SOPLEX_SUBVERSION.

const char* SCIPlpiGetSolverDesc ( void )

gets description of LP solver (developer, webpage, ...)

Definition at line 442 of file lpi_clp.cpp.

void* SCIPlpiGetSolverPointer ( SCIP_LPI * lpi )

gets pointer for LP solver - use only with great care

The behavior of this function depends on the solver and its use is therefore only recommended if you really know what you are doing. In general, it returns a pointer to the LP solver object.

gets pointer for LP solver - use only with great care

Here we return the pointer to the LP environment.

gets pointer for LP solver - use only with great care

Here we return the pointer to the model.

Parameters

lpi	pointer to an LP interface structure

Definition at line 450 of file lpi_clp.cpp.

References NULL.

SCIP_RETCODE SCIPlpiCreate	(	SCIP_LPI **	lpi,
		SCIP_MESSAGEHDLR *	messagehdlr,
		const char *	name,
		SCIP_OBJSEN	objsen
	)

creates an LP problem object

Returns: SCIP_OK on success

Parameters

lpi	pointer to an LP interface structure
messagehdlr	message handler to use for printing messages, or NULL
name	problem name
objsen	objective sense

Definition at line 469 of file lpi_clp.cpp.

References CHECK_ZERO, DEGEN_LEVEL, FALSE, MOSEK_CALL, NULL, SCIP_ALLOC, SCIP_Bool, SCIP_CALL, SCIP_LPERROR, SCIP_LPPAR_PRICING, SCIP_OKAY, SCIP_PRICING_LPIDEFAULT, SCIP_Real, SCIPdebugMessage, SCIPerrorMessage, SCIPlpiChgObjsen(), SCIPlpiInfinity(), SCIPlpiSetIntpar(), SCIPmessagePrintWarning(), SENSE2MOSEK, SETBACK_LIMIT, SOPLEX_TRY, SOPLEX_VERBLEVEL, and TRUE.

SCIP_RETCODE SCIPlpiFree ( SCIP_LPI ** lpi )

deletes an LP problem object

Parameters

lpi	pointer to an LP interface structure

Definition at line 538 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, SCIP_OKAY, and SCIPdebugMessage.

SCIP_RETCODE SCIPlpiLoadColLP	(	SCIP_LPI *	lpi,
		SCIP_OBJSEN	objsen,
		int	ncols,
		const SCIP_Real *	obj,
		const SCIP_Real *	lb,
		const SCIP_Real *	ub,
		char **	colnames,
		int	nrows,
		const SCIP_Real *	lhs,
		const SCIP_Real *	rhs,
		char **	rownames,
		int	nnonz,
		const int *	beg,
		const int *	ind,
		const SCIP_Real *	val
	)

copies LP data with column matrix into LP solver

Parameters

lpi	LP interface structure
objsen	objective sense
ncols	number of columns
obj	objective function values of columns
lb	lower bounds of columns
ub	upper bounds of columns
colnames	column names, or NULL
nrows	number of rows
lhs	left hand sides of rows
rhs	right hand sides of rows
rownames	row names, or NULL
nnonz	number of nonzero elements in the constraint matrix
beg	start index of each column in ind- and val-array
ind	row indices of constraint matrix entries
val	values of constraint matrix entries

Definition at line 572 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_CONDRET, QS_RETURN, SCIP_ALLOC, SCIP_CALL, SCIP_LPERROR, SCIP_OBJSEN_MAXIMIZE, SCIP_OBJSEN_MINIMIZE, SCIP_OKAY, SCIP_Real, SCIPdebugMessage, SCIPlpiAddCols(), SCIPlpiChgObjsen(), SCIPlpiClear(), SCIPmessagePrintWarning(), and SENSE2MOSEK.

SCIP_RETCODE SCIPlpiAddCols	(	SCIP_LPI *	lpi,
		int	ncols,
		const SCIP_Real *	obj,
		const SCIP_Real *	lb,
		const SCIP_Real *	ub,
		char **	colnames,
		int	nnonz,
		const int *	beg,
		const int *	ind,
		const SCIP_Real *	val
	)

adds columns to the LP

Note: ind array is not checked for duplicates, problems may appear if indeces are added more than once

adds columns to the LP

Parameters

lpi	LP interface structure
ncols	number of columns to be added
obj	objective function values of new columns
lb	lower bounds of new columns
ub	upper bounds of new columns
colnames	column names, or NULL
nnonz	number of nonzero elements to be added to the constraint matrix
beg	start index of each column in ind- and val-array, or NULL if nnonz == 0
ind	row indices of constraint matrix entries, or NULL if nnonz == 0
val	values of constraint matrix entries, or NULL if nnonz == 0

Definition at line 638 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_RETURN, SCIP_ALLOC, SCIP_CALL, SCIP_LPERROR, SCIP_OKAY, SCIP_Real, SCIPdebugMessage, and SCIPmessagePrintWarning().

Referenced by SCIPlpiLoadColLP().

SCIP_RETCODE SCIPlpiDelCols	(	SCIP_LPI *	lpi,
		int	firstcol,
		int	lastcol
	)

deletes all columns in the given range from LP

Parameters

lpi	LP interface structure
firstcol	first column to be deleted
lastcol	last column to be deleted

Definition at line 705 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_RETURN, SCIP_ALLOC, SCIP_CALL, SCIP_OKAY, SCIPdebugMessage, and SOPLEX_TRY.

Referenced by SCIPlpiClear().

SCIP_RETCODE SCIPlpiDelColset	(	SCIP_LPI *	lpi,
		int *	dstat
	)

deletes columns from SCIP_LPI; the new position of a column must not be greater that its old position

deletes columns from SCIP_LP; the new position of a column must not be greater that its old position

Parameters

lpi	LP interface structure
dstat	deletion status of columns input: 1 if column should be deleted, 0 if not output: new position of column, -1 if column was deleted

Definition at line 736 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_CONDRET, SCIP_ALLOC, SCIP_CALL, SCIP_OKAY, SCIPdebugMessage, and SOPLEX_TRY.

SCIP_RETCODE SCIPlpiAddRows	(	SCIP_LPI *	lpi,
		int	nrows,
		const SCIP_Real *	lhs,
		const SCIP_Real *	rhs,
		char **	rownames,
		int	nnonz,
		const int *	beg,
		const int *	ind,
		const SCIP_Real *	val
	)

adds rows to the LP

Note: ind array is not checked for duplicates, problems may appear if indeces are added more than once

adds rows to the LP

Parameters

lpi	LP interface structure
nrows	number of rows to be added
lhs	left hand sides of new rows
rhs	right hand sides of new rows
rownames	row names, or NULL
nnonz	number of nonzero elements to be added to the constraint matrix
beg	start index of each row in ind- and val-array, or NULL if nnonz == 0
ind	column indices of constraint matrix entries, or NULL if nnonz == 0
val	values of constraint matrix entries, or NULL if nnonz == 0

Definition at line 782 of file lpi_clp.cpp.

References CHECK_ZERO, FALSE, MOSEK_CALL, NULL, QS_ERROR, SCIP_ALLOC, SCIP_CALL, SCIP_LPERROR, SCIP_LPPAR_SCALING, SCIP_OKAY, SCIP_Real, SCIPdebugMessage, SCIPlpiSetIntpar(), SCIPmessagePrintWarning(), and TRUE.

SCIP_RETCODE SCIPlpiDelRows	(	SCIP_LPI *	lpi,
		int	firstrow,
		int	lastrow
	)

deletes all rows in the given range from LP

Parameters

lpi	LP interface structure
firstrow	first row to be deleted
lastrow	last row to be deleted

Definition at line 844 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_RETURN, SCIP_ALLOC, SCIP_CALL, SCIP_OKAY, SCIPdebugMessage, and SOPLEX_TRY.

Referenced by SCIPlpiClear().

SCIP_RETCODE SCIPlpiDelRowset	(	SCIP_LPI *	lpi,
		int *	dstat
	)

deletes rows from SCIP_LPI; the new position of a row must not be greater that its old position

deletes rows from SCIP_LP; the new position of a row must not be greater that its old position

Parameters

lpi	LP interface structure
dstat	deletion status of rows input: 1 if row should be deleted, 0 if not output: new position of row, -1 if row was deleted

Definition at line 876 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_CONDRET, SCIP_ALLOC, SCIP_CALL, SCIP_OKAY, SCIPdebugMessage, and SOPLEX_TRY.

SCIP_RETCODE SCIPlpiClear ( SCIP_LPI * lpi )

clears the whole LP

Parameters

lpi	LP interface structure

Definition at line 922 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_CONDRET, SCIP_CALL, SCIP_OKAY, SCIPdebugMessage, SCIPlpiDelCols(), SCIPlpiDelRows(), and SOPLEX_TRY.

Referenced by SCIPlpiLoadColLP().

SCIP_RETCODE SCIPlpiChgBounds	(	SCIP_LPI *	lpi,
		int	ncols,
		const int *	ind,
		const SCIP_Real *	lb,
		const SCIP_Real *	ub
	)

changes lower and upper bounds of columns

Parameters

lpi	LP interface structure
ncols	number of columns to change bounds for
ind	column indices
lb	values for the new lower bounds
ub	values for the new upper bounds

Definition at line 941 of file lpi_clp.cpp.

References CHECK_ZERO, CPX_MAGICZEROCONSTANT, EPSZ, MOSEK_CALL, NULL, QS_CONDRET, QS_RETURN, SCIP_ALLOC, SCIP_CALL, SCIP_LPERROR, SCIP_OKAY, SCIP_Real, SCIPdebugMessage, SCIPdebugPrintf, and SCIPmessagePrintWarning().

Referenced by SCIPlpiScaleCol().

SCIP_RETCODE SCIPlpiChgSides	(	SCIP_LPI *	lpi,
		int	nrows,
		const int *	ind,
		const SCIP_Real *	lhs,
		const SCIP_Real *	rhs
	)

changes left and right hand sides of rows

Parameters

lpi	LP interface structure
nrows	number of rows to change sides for
ind	row indices
lhs	new values for left hand sides
rhs	new values for right hand sides

Definition at line 1007 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_CONDRET, SCIP_ALLOC, SCIP_CALL, SCIP_LPERROR, SCIP_OKAY, SCIPdebugMessage, and SCIPmessagePrintWarning().

Referenced by SCIPlpiScaleRow().

SCIP_RETCODE SCIPlpiChgCoef	(	SCIP_LPI *	lpi,
		int	row,
		int	col,
		SCIP_Real	newval
	)

changes a single coefficient

Parameters

lpi	LP interface structure
row	row number of coefficient to change
col	column number of coefficient to change
newval	new value of coefficient

Definition at line 1035 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_RETURN, SCIP_CALL, SCIP_OKAY, SCIPdebugMessage, and SOPLEX_TRY.

Referenced by SCIPlpiScaleCol(), and SCIPlpiScaleRow().

SCIP_RETCODE SCIPlpiChgObjsen	(	SCIP_LPI *	lpi,
		SCIP_OBJSEN	objsense
	)

changes the objective sense

Parameters

lpi	LP interface structure
objsense	new objective sense

Definition at line 1058 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_CONDRET, SCIP_OBJSEN_MAXIMIZE, SCIP_OBJSEN_MINIMIZE, SCIP_OKAY, SCIPdebugMessage, SENSE2MOSEK, and SOPLEX_TRY.

Referenced by SCIPlpiCreate(), and SCIPlpiLoadColLP().

SCIP_RETCODE SCIPlpiChgObj	(	SCIP_LPI *	lpi,
		int	ncols,
		int *	ind,
		SCIP_Real *	obj
	)

changes objective values of columns in the LP

Parameters

lpi	LP interface structure
ncols	number of columns to change objective value for
ind	column indices to change objective value for
obj	new objective values for columns

Definition at line 1078 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_CONDRET, SCIP_CALL, SCIP_LPERROR, SCIP_OKAY, SCIPdebugMessage, and SCIPmessagePrintWarning().

Referenced by SCIPlpiScaleCol().

SCIP_RETCODE SCIPlpiScaleRow	(	SCIP_LPI *	lpi,
		int	row,
		SCIP_Real	scaleval
	)

multiplies a row with a non-zero scalar; for negative scalars, the row's sense is switched accordingly

Parameters

lpi	LP interface structure
row	row number to scale
scaleval	scaling multiplier

Definition at line 1105 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_RETURN, QS_TESTG, SCIP_ALLOC, SCIP_CALL, SCIP_LPERROR, SCIP_OKAY, SCIP_Real, SCIPdebugMessage, SCIPerrorMessage, SCIPlpiChgCoef(), SCIPlpiChgSides(), SCIPlpiGetRows(), and SCIPmessagePrintWarning().

SCIP_RETCODE SCIPlpiScaleCol	(	SCIP_LPI *	lpi,
		int	col,
		SCIP_Real	scaleval
	)

multiplies a column with a non-zero scalar; the objective value is multiplied with the scalar, and the bounds are divided by the scalar; for negative scalars, the column's bounds are switched

Parameters

lpi	LP interface structure
col	column number to scale
scaleval	scaling multiplier

Definition at line 1178 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_RETURN, QS_TESTG, SCIP_ALLOC, SCIP_CALL, SCIP_LPERROR, SCIP_OKAY, SCIP_Real, SCIPdebugMessage, SCIPlpiChgBounds(), SCIPlpiChgCoef(), SCIPlpiChgObj(), SCIPlpiGetCols(), SCIPlpiGetObj(), and SCIPmessagePrintWarning().

SCIP_RETCODE SCIPlpiGetNRows	(	SCIP_LPI *	lpi,
		int *	nrows
	)

gets the number of rows in the LP

Parameters

lpi	LP interface structure
nrows	pointer to store the number of rows

Definition at line 1255 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, SCIP_OKAY, and SCIPdebugMessage.

SCIP_RETCODE SCIPlpiGetNCols	(	SCIP_LPI *	lpi,
		int *	ncols
	)

gets the number of columns in the LP

Parameters

lpi	LP interface structure
ncols	pointer to store the number of cols

Definition at line 1273 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, SCIP_OKAY, and SCIPdebugMessage.

SCIP_RETCODE SCIPlpiGetObjsen	(	SCIP_LPI *	lpi,
		SCIP_OBJSEN *	objsen
	)

gets the objective sense of the LP

gets objective sense of the LP

Parameters

lpi	LP interface structure
objsen	pointer to store objective sense

Definition at line 1493 of file lpi_clp.cpp.

References CHECK_ZERO, NULL, SCIP_LPERROR, SCIP_OBJSEN_MAXIMIZE, SCIP_OBJSEN_MINIMIZE, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIPdebugMessage, and SCIPerrorMessage.

SCIP_RETCODE SCIPlpiGetNNonz	(	SCIP_LPI *	lpi,
		int *	nnonz
	)

gets the number of nonzero elements in the LP constraint matrix

Parameters

lpi	LP interface structure
nnonz	pointer to store the number of nonzeros

Definition at line 1291 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, SCIP_OKAY, SCIP_PLUGINNOTFOUND, and SCIPdebugMessage.

Referenced by SCIPlpiGetCols(), and SCIPlpiGetRows().

SCIP_RETCODE SCIPlpiGetCols	(	SCIP_LPI *	lpi,
		int	firstcol,
		int	lastcol,
		SCIP_Real *	lb,
		SCIP_Real *	ub,
		int *	nnonz,
		int *	beg,
		int *	ind,
		SCIP_Real *	val
	)

gets columns from LP problem object; the arrays have to be large enough to store all values; Either both, lb and ub, have to be NULL, or both have to be non-NULL, either nnonz, beg, ind, and val have to be NULL, or all of them have to be non-NULL.

gets columns from LP problem object; the arrays have to be large enough to store all values Either both, lb and ub, have to be 0, or both have to be non-0, either nnonz, beg, ind, and val have to be 0, or all of them have to be non-0.

gets columns from LP problem object; the arrays have to be large enough to store all values Either both, lb and ub, have to be NULL, or both have to be non-NULL, either nnonz, beg, ind, and val have to be NULL, or all of them have to be non-NULL.

Parameters

lpi	LP interface structure
firstcol	first column to get from LP
lastcol	last column to get from LP
lb	buffer to store the lower bound vector, or NULL
ub	buffer to store the upper bound vector, or NULL
nnonz	pointer to store the number of nonzero elements returned, or NULL
beg	buffer to store start index of each column in ind- and val-array, or NULL
ind	buffer to store column indices of constraint matrix entries, or NULL
val	buffer to store values of constraint matrix entries, or NULL

Definition at line 1312 of file lpi_clp.cpp.

References CHECK_ZERO, NULL, QS_RETURN, QS_TESTG, SCIP_CALL, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIPdebugMessage, SCIPlpiGetBounds(), and SCIPlpiGetNNonz().

Referenced by SCIPlpiScaleCol().

SCIP_RETCODE SCIPlpiGetRows	(	SCIP_LPI *	lpi,
		int	firstrow,
		int	lastrow,
		SCIP_Real *	lhss,
		SCIP_Real *	rhss,
		int *	nnonz,
		int *	beg,
		int *	ind,
		SCIP_Real *	val
	)

gets rows from LP problem object; the arrays have to be large enough to store all values. Either both, lhs and rhs, have to be NULL, or both have to be non-NULL, either nnonz, beg, ind, and val have to be NULL, or all of them have to be non-NULL.

gets rows from LP problem object; the arrays have to be large enough to store all values. Either both, lhs and rhs, have to be 0, or both have to be non-0, either nnonz, beg, ind, and val have to be 0, or all of them have to be non-0.

Parameters

lpi	LP interface structure
firstrow	first row to get from LP
lastrow	last row to get from LP
lhss	buffer to store left hand side vector, or NULL
rhss	buffer to store right hand side vector, or NULL
nnonz	pointer to store the number of nonzero elements returned, or NULL
beg	buffer to store start index of each row in ind- and val-array, or NULL
ind	buffer to store row indices of constraint matrix entries, or NULL
val	buffer to store values of constraint matrix entries, or NULL

Definition at line 1379 of file lpi_clp.cpp.

References CHECK_ZERO, NULL, QS_RETURN, QS_TESTG, SCIP_CALL, SCIP_INVALIDDATA, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIPABORT, SCIPdebugMessage, SCIPerrorMessage, SCIPlpiGetNNonz(), and SCIPlpiGetSides().

Referenced by SCIPlpiScaleRow().

SCIP_RETCODE SCIPlpiGetColNames	(	SCIP_LPI *	lpi,
		int	firstcol,
		int	lastcol,
		char **	colnames,
		char *	namestorage,
		int	namestoragesize,
		int *	storageleft
	)

gets column names

Parameters

lpi	LP interface structure
firstcol	first column to get name from LP
lastcol	last column to get name from LP
colnames	pointers to column names (of size at least lastcol-firstcol+1)
namestorage	storage for col names
namestoragesize	size of namestorage (if 0, storageleft returns the storage needed)
storageleft	amount of storage left (if < 0 the namestorage was not big enough)

Definition at line 1443 of file lpi_clp.cpp.

References CHECK_ZERO, NULL, QS_ERROR, SCIP_ALLOC, SCIP_LPERROR, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIPdebugMessage, and SCIPerrorMessage.

SCIP_RETCODE SCIPlpiGetRowNames	(	SCIP_LPI *	lpi,
		int	firstrow,
		int	lastrow,
		char **	rownames,
		char *	namestorage,
		int	namestoragesize,
		int *	storageleft
	)

gets row names

Parameters

lpi	LP interface structure
firstrow	first row to get name from LP
lastrow	last row to get name from LP
rownames	pointers to row names (of size at least lastrow-firstrow+1)
namestorage	storage for row names
namestoragesize	size of namestorage (if 0, -storageleft returns the storage needed)
storageleft	amount of storage left (if < 0 the namestorage was not big enough)

Definition at line 1459 of file lpi_clp.cpp.

References CHECK_ZERO, NULL, QS_ERROR, SCIP_ALLOC, SCIP_LPERROR, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIPdebugMessage, and SCIPerrorMessage.

SCIP_RETCODE SCIPlpiGetObj	(	SCIP_LPI *	lpi,
		int	firstcol,
		int	lastcol,
		SCIP_Real *	vals
	)

gets objective coefficients from LP problem object

Parameters

lpi	LP interface structure
firstcol	first column to get objective coefficient for
lastcol	last column to get objective coefficient for
vals	array to store objective coefficients

Definition at line 1513 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_RETURN, SCIP_CALL, SCIP_OKAY, SCIP_PLUGINNOTFOUND, and SCIPdebugMessage.

Referenced by SCIPlpiScaleCol().

SCIP_RETCODE SCIPlpiGetBounds	(	SCIP_LPI *	lpi,
		int	firstcol,
		int	lastcol,
		SCIP_Real *	lbs,
		SCIP_Real *	ubs
	)

gets current bounds from LP problem object

Parameters

lpi	LP interface structure
firstcol	first column to get bounds for
lastcol	last column to get bounds for
lbs	array to store lower bound values, or NULL
ubs	array to store upper bound values, or NULL

Definition at line 1536 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_RETURN, SCIP_CALL, SCIP_OKAY, SCIP_PLUGINNOTFOUND, and SCIPdebugMessage.

Referenced by SCIPlpiGetCols().

SCIP_RETCODE SCIPlpiGetSides	(	SCIP_LPI *	lpi,
		int	firstrow,
		int	lastrow,
		SCIP_Real *	lhss,
		SCIP_Real *	rhss
	)

gets current row sides from LP problem object

Parameters

lpi	LP interface structure
firstrow	first row to get sides for
lastrow	last row to get sides for
lhss	array to store left hand side values, or NULL
rhss	array to store right hand side values, or NULL

Definition at line 1567 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_RETURN, QS_TESTG, SCIP_CALL, SCIP_INVALIDDATA, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIPABORT, SCIPdebugMessage, and SCIPerrorMessage.

Referenced by SCIPlpiGetRows().

SCIP_RETCODE SCIPlpiGetCoef	(	SCIP_LPI *	lpi,
		int	row,
		int	col,
		SCIP_Real *	val
	)

gets a single coefficient

Parameters

lpi	LP interface structure
row	row number of coefficient
col	column number of coefficient
val	pointer to store the value of the coefficient

Definition at line 1598 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_RETURN, SCIP_CALL, SCIP_OKAY, SCIP_PLUGINNOTFOUND, and SCIPdebugMessage.

SCIP_RETCODE SCIPlpiSolvePrimal ( SCIP_LPI * lpi )

calls primal simplex to solve the LP

startFinishOptions - bits 1 - do not delete work areas and factorization at end 2 - use old factorization if same number of rows 4 - skip as much initialization of work areas as possible (work in progress)

4 does not seem to work.

Primal algorithm

Parameters

lpi	LP interface structure

Definition at line 1632 of file lpi_clp.cpp.

References CHECK_ZERO, FALSE, GRB_INT_PAR_METHOD, GRB_METHOD_PRIMAL, MOSEK_CALL, NULL, QS_RETURN, SCIP_Bool, SCIP_CALL, SCIP_LPERROR, SCIP_NOMEMORY, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIPdebugMessage, SCIPerrorMessage, SCIPlpiWriteLP(), SCIPlpiWriteState(), TRUE, and WRITE_ABOVE.

SCIP_RETCODE SCIPlpiSolveDual ( SCIP_LPI * lpi )

calls dual simplex to solve the LP

startFinishOptions - bits 1 - do not delete work areas and factorization at end 2 - use old factorization if same number of rows 4 - skip as much initialization of work areas as possible (work in progress)

4 does not seem to work.

Dual algorithm

Parameters

lpi	LP interface structure

Definition at line 1705 of file lpi_clp.cpp.

References CHECK_ZERO, FALSE, GRB_INT_PAR_METHOD, GRB_METHOD_DUAL, MOSEK_CALL, NULL, QS_RETURN, SCIP_Bool, SCIP_CALL, SCIP_LPERROR, SCIP_NOMEMORY, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIP_Real, SCIPdebugMessage, SCIPerrorMessage, SCIPlpiGetObjval(), SCIPlpiIsObjlimExc(), SCIPlpiWriteLP(), SCIPlpiWriteState(), TRUE, and WRITE_ABOVE.

Referenced by SCIPlpiSolveBarrier().

SCIP_RETCODE SCIPlpiSolveBarrier	(	SCIP_LPI *	lpi,
		SCIP_Bool	crossover
	)

calls barrier or interior point algorithm to solve the LP with crossover to simplex basis

Parameters

lpi	LP interface structure
crossover	perform crossover

Definition at line 1780 of file lpi_clp.cpp.

References CHECK_ZERO, FALSE, GRB_INT_PAR_METHOD, MOSEK_CALL, NULL, SCIP_CALL, SCIP_INVALIDCALL, SCIP_LPERROR, SCIP_NOMEMORY, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIPdebugMessage, SCIPerrorMessage, SCIPlpiSolveDual(), TRUE, and WRITE_ABOVE.

SCIP_RETCODE SCIPlpiStartStrongbranch ( SCIP_LPI * lpi )

start strong branching - call before any strong branching

start strong branching - call before any strongbranching

start strong branching

Parameters

lpi	LP interface structure

Definition at line 1821 of file lpi_clp.cpp.

References NULL, and SCIP_OKAY.

SCIP_RETCODE SCIPlpiEndStrongbranch ( SCIP_LPI * lpi )

end strong branching - call after any strong branching

end strong branching - call after any strongbranching

end strong branching

Parameters

lpi	LP interface structure

Definition at line 1830 of file lpi_clp.cpp.

References NULL, and SCIP_OKAY.

SCIP_RETCODE SCIPlpiStrongbranchFrac	(	SCIP_LPI *	lpi,
		int	col,
		SCIP_Real	psol,
		int	itlim,
		SCIP_Real *	down,
		SCIP_Real *	up,
		SCIP_Bool *	downvalid,
		SCIP_Bool *	upvalid,
		int *	iter
	)

performs strong branching iterations on one fractional candidate

Parameters

lpi	LP interface structure
col	column to apply strong branching on
psol	fractional current primal solution value of column
itlim	iteration limit for strong branchings
down	stores dual bound after branching column down
up	stores dual bound after branching column up
downvalid	stores whether the returned down value is a valid dual bound; otherwise, it can only be used as an estimate value
upvalid	stores whether the returned up value is a valid dual bound; otherwise, it can only be used as an estimate value
iter	stores total number of strong branching iterations, or -1; may be NULL

Definition at line 2169 of file lpi_clp.cpp.

References CHECK_ZERO, EPSISINT, FALSE, NULL, QS_CONDRET, SCIP_CALL, SCIP_LPERROR, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIPdebugMessage, and TRUE.

SCIP_RETCODE SCIPlpiStrongbranchesFrac	(	SCIP_LPI *	lpi,
		int *	cols,
		int	ncols,
		SCIP_Real *	psols,
		int	itlim,
		SCIP_Real *	down,
		SCIP_Real *	up,
		SCIP_Bool *	downvalid,
		SCIP_Bool *	upvalid,
		int *	iter
	)

performs strong branching iterations on given fractional candidates

Parameters

lpi	LP interface structure
cols	columns to apply strong branching on
ncols	number of columns
psols	fractional current primal solution values of columns
itlim	iteration limit for strong branchings
down	stores dual bounds after branching columns down
up	stores dual bounds after branching columns up
downvalid	stores whether the returned down values are valid dual bounds; otherwise, they can only be used as an estimate values
upvalid	stores whether the returned up values are a valid dual bounds; otherwise, they can only be used as an estimate values
iter	stores total number of strong branching iterations, or -1; may be NULL

Definition at line 2190 of file lpi_clp.cpp.

References CHECK_ZERO, EPSISINT, FALSE, NULL, QS_CONDRET, SCIP_CALL, SCIP_LPERROR, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIPdebugMessage, and TRUE.

SCIP_RETCODE SCIPlpiStrongbranchInt	(	SCIP_LPI *	lpi,
		int	col,
		SCIP_Real	psol,
		int	itlim,
		SCIP_Real *	down,
		SCIP_Real *	up,
		SCIP_Bool *	downvalid,
		SCIP_Bool *	upvalid,
		int *	iter
	)

performs strong branching iterations on one candidate with integral value

Parameters

lpi	LP interface structure
col	column to apply strong branching on
psol	current integral primal solution value of column
itlim	iteration limit for strong branchings
down	stores dual bound after branching column down
up	stores dual bound after branching column up
downvalid	stores whether the returned down value is a valid dual bound; otherwise, it can only be used as an estimate value
upvalid	stores whether the returned up value is a valid dual bound; otherwise, it can only be used as an estimate value
iter	stores total number of strong branching iterations, or -1; may be NULL

Definition at line 2215 of file lpi_clp.cpp.

References EPSISINT, NULL, QS_CONDRET, SCIP_CALL, SCIP_LPERROR, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIP_Real, SCIPdebugMessage, and TRUE.

SCIP_RETCODE SCIPlpiStrongbranchesInt	(	SCIP_LPI *	lpi,
		int *	cols,
		int	ncols,
		SCIP_Real *	psols,
		int	itlim,
		SCIP_Real *	down,
		SCIP_Real *	up,
		SCIP_Bool *	downvalid,
		SCIP_Bool *	upvalid,
		int *	iter
	)

performs strong branching iterations on given candidates with integral values

Parameters

lpi	LP interface structure
cols	columns to apply strong branching on
ncols	number of columns
psols	current integral primal solution values of columns
itlim	iteration limit for strong branchings
down	stores dual bounds after branching columns down
up	stores dual bounds after branching columns up
downvalid	stores whether the returned down values are valid dual bounds; otherwise, they can only be used as an estimate values
upvalid	stores whether the returned up values are a valid dual bounds; otherwise, they can only be used as an estimate values
iter	stores total number of strong branching iterations, or -1; may be NULL

Definition at line 2236 of file lpi_clp.cpp.

References EPSISINT, NULL, QS_CONDRET, SCIP_CALL, SCIP_LPERROR, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIP_Real, SCIPdebugMessage, and TRUE.

SCIP_Bool SCIPlpiWasSolved ( SCIP_LPI * lpi )

returns whether a solve method was called after the last modification of the LP

Parameters

lpi	LP interface structure

Definition at line 2271 of file lpi_clp.cpp.

References FALSE, NULL, SCIP_ABORT_FALSE, and SCIPdebugMessage.

SCIP_RETCODE SCIPlpiGetSolFeasibility	(	SCIP_LPI *	lpi,
		SCIP_Bool *	primalfeasible,
		SCIP_Bool *	dualfeasible
	)

gets information about primal and dual feasibility of the current LP solution

here "true" should mean feasible, "false" should mean unknown

Parameters

lpi	LP interface structure
primalfeasible	stores primal feasibility status
dualfeasible	stores dual feasibility status

Definition at line 2281 of file lpi_clp.cpp.

References CHECK_ZERO, FALSE, GRB_INT_PAR_METHOD, GRB_METHOD_DUAL, GRB_METHOD_PRIMAL, MOSEK_CALL, NULL, SCIP_Bool, SCIP_LPERROR, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIP_Real, SCIPdebugMessage, SCIPlpiIsDualFeasible(), SCIPlpiIsPrimalFeasible(), SUMINFEASBOUND, TRUE, and XPRS_LP_OPTIMAL_SCALEDINFEAS.

Referenced by SCIPlpiIsPrimalUnbounded().

SCIP_Bool SCIPlpiExistsPrimalRay ( SCIP_LPI * lpi )

returns TRUE iff LP is proven to have a primal unbounded ray (but not necessary a primal feasible point); this does not necessarily mean, that the solver knows and can return the primal ray

Parameters

lpi	LP interface structure

Definition at line 2326 of file lpi_clp.cpp.

References FALSE, NULL, SCIP_ABORT_FALSE, and SCIPdebugMessage.

Referenced by SCIPlpiIsDualInfeasible().

SCIP_Bool SCIPlpiHasPrimalRay ( SCIP_LPI * lpi )

returns TRUE iff LP is proven to have a primal unbounded ray (but not necessary a primal feasible point), and the solver knows and can return the primal ray

Parameters

lpi	LP interface structure

Definition at line 2344 of file lpi_clp.cpp.

References ABORT_ZERO, FALSE, NULL, SCIP_ABORT_FALSE, and SCIPdebugMessage.

SCIP_Bool SCIPlpiIsPrimalUnbounded ( SCIP_LPI * lpi )

returns TRUE iff LP is proven to be primal unbounded

returns TRUE iff LP is proven to be primal feasible and unbounded

Parameters

lpi	LP interface structure

Definition at line 2360 of file lpi_clp.cpp.

References ABORT_ZERO, FALSE, NULL, SCIP_Bool, SCIP_OKAY, SCIPdebugMessage, and SCIPlpiGetSolFeasibility().

SCIP_Bool SCIPlpiIsPrimalInfeasible ( SCIP_LPI * lpi )

returns TRUE iff LP is proven to be primal infeasible

Parameters

lpi	LP interface structure

Definition at line 2374 of file lpi_clp.cpp.

References ABORT_ZERO, FALSE, NULL, SCIPdebugMessage, and SCIPlpiExistsDualRay().

SCIP_Bool SCIPlpiIsPrimalFeasible ( SCIP_LPI * lpi )

returns TRUE iff LP is proven to be primal feasible

Parameters

lpi	LP interface structure

Definition at line 2393 of file lpi_clp.cpp.

References ABORT_ZERO, CHECK_ZERO, FALSE, GRB_INT_PAR_METHOD, GRB_METHOD_PRIMAL, NULL, SCIP_ABORT_FALSE, SCIP_Bool, SCIPdebugMessage, and XPRS_LP_OPTIMAL_SCALEDINFEAS.

Referenced by SCIPlpiGetSolFeasibility(), and SCIPlpiIsOptimal().

SCIP_Bool SCIPlpiExistsDualRay ( SCIP_LPI * lpi )

returns TRUE iff LP is proven to have a dual unbounded ray (but not necessary a dual feasible point); this does not necessarily mean, that the solver knows and can return the dual ray

Parameters

lpi	LP interface structure

Definition at line 2409 of file lpi_clp.cpp.

References FALSE, NULL, SCIP_ABORT_FALSE, and SCIPdebugMessage.

Referenced by SCIPlpiGetState(), and SCIPlpiIsPrimalInfeasible().

SCIP_Bool SCIPlpiHasDualRay ( SCIP_LPI * lpi )

returns TRUE iff LP is proven to have a dual unbounded ray (but not necessary a dual feasible point), and the solver knows and can return the dual ray

Parameters

lpi	LP interface structure

Definition at line 2427 of file lpi_clp.cpp.

References ABORT_ZERO, CHECK_ZERO, FALSE, GRB_INT_PAR_METHOD, GRB_METHOD_DUAL, NULL, SCIP_ABORT_FALSE, SCIPdebugMessage, and TRUE.

SCIP_Bool SCIPlpiIsDualUnbounded ( SCIP_LPI * lpi )

returns TRUE iff LP is proven to be dual unbounded

returns TRUE iff LP is dual unbounded

Parameters

lpi	LP interface structure

Definition at line 2455 of file lpi_clp.cpp.

References ABORT_ZERO, CHECK_ZERO, FALSE, GRB_INT_PAR_METHOD, GRB_METHOD_DUAL, NULL, and SCIPdebugMessage.

SCIP_Bool SCIPlpiIsDualInfeasible ( SCIP_LPI * lpi )

returns TRUE iff LP is proven to be dual infeasible

returns TRUE iff LP is dual infeasible

Parameters

lpi	LP interface structure

Definition at line 2472 of file lpi_clp.cpp.

References ABORT_ZERO, FALSE, NULL, SCIPdebugMessage, and SCIPlpiExistsPrimalRay().

SCIP_Bool SCIPlpiIsDualFeasible ( SCIP_LPI * lpi )

returns TRUE iff LP is proven to be dual feasible

Parameters

lpi	LP interface structure

Definition at line 2486 of file lpi_clp.cpp.

References ABORT_ZERO, CHECK_ZERO, FALSE, GRB_INT_PAR_METHOD, GRB_METHOD_DUAL, NULL, SCIP_ABORT_FALSE, SCIP_Bool, SCIPdebugMessage, and XPRS_LP_OPTIMAL_SCALEDINFEAS.

Referenced by SCIPlpiGetSolFeasibility(), and SCIPlpiIsOptimal().

SCIP_Bool SCIPlpiIsOptimal ( SCIP_LPI * lpi )

returns TRUE iff LP was solved to optimality

Parameters

lpi	LP interface structure

Definition at line 2500 of file lpi_clp.cpp.

References FALSE, NULL, SCIP_ABORT_FALSE, SCIPdebugMessage, SCIPlpiIsDualFeasible(), SCIPlpiIsObjlimExc(), SCIPlpiIsPrimalFeasible(), and XPRS_LP_OPTIMAL_SCALEDINFEAS.

Referenced by SCIPlpiIsStable().

SCIP_Bool SCIPlpiIsStable ( SCIP_LPI * lpi )

returns TRUE iff current LP basis is stable

Parameters

lpi	LP interface structure

Definition at line 2518 of file lpi_clp.cpp.

References ABORT_ZERO, FALSE, NULL, SCIP_INVALID, SCIP_LPSOLQUALITY_ESTIMCONDITION, SCIP_OKAY, SCIP_Real, SCIPABORT, SCIPdebugMessage, SCIPlpiGetRealSolQuality(), SCIPlpiIsObjlimExc(), SCIPlpiIsOptimal(), TRUE, and XPRS_LP_OPTIMAL_SCALEDINFEAS.

SCIP_Bool SCIPlpiIsObjlimExc ( SCIP_LPI * lpi )

returns TRUE iff the objective limit was reached

Parameters

lpi	LP interface structure

Definition at line 2556 of file lpi_clp.cpp.

References FALSE, NULL, SCIPdebugMessage, and TRUE.

Referenced by SCIPlpiIsOptimal(), SCIPlpiIsStable(), and SCIPlpiSolveDual().

SCIP_Bool SCIPlpiIsIterlimExc ( SCIP_LPI * lpi )

returns TRUE iff the iteration limit was reached

Parameters

lpi	LP interface structure

Definition at line 2588 of file lpi_clp.cpp.

References ABORT_ZERO, FALSE, NULL, SCIPdebugMessage, and TRUE.

SCIP_Bool SCIPlpiIsTimelimExc ( SCIP_LPI * lpi )

returns TRUE iff the time limit was reached

Parameters

lpi	LP interface structure

Definition at line 2604 of file lpi_clp.cpp.

References ABORT_ZERO, FALSE, NULL, SCIPdebugMessage, and TRUE.

int SCIPlpiGetInternalStatus ( SCIP_LPI * lpi )

returns the internal solution status of the solver

Parameters

lpi	LP interface structure

Definition at line 2620 of file lpi_clp.cpp.

References FALSE, NULL, SCIP_OKAY, and SCIPdebugMessage.

SCIP_RETCODE SCIPlpiIgnoreInstability	(	SCIP_LPI *	lpi,
		SCIP_Bool *	success
	)

tries to reset the internal status of the LP solver in order to ignore an instability of the last solving call

Parameters

lpi	LP interface structure
success	pointer to store, whether the instability could be ignored

Definition at line 1475 of file lpi_clp.cpp.

References FALSE, NULL, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIPdebugMessage, and TRUE.

SCIP_RETCODE SCIPlpiGetObjval	(	SCIP_LPI *	lpi,
		SCIP_Real *	objval
	)

gets objective value of solution

Note: if the solution status is iteration limit reached (GRB_ITERATION_LIMIT), the objective value was not computed

Parameters

lpi	LP interface structure
objval	stores the objective value

Definition at line 2634 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_RETURN, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIPdebugMessage, and SCIPlpiInfinity().

Referenced by SCIPlpiSolveDual().

SCIP_RETCODE SCIPlpiGetSol	(	SCIP_LPI *	lpi,
		SCIP_Real *	objval,
		SCIP_Real *	primsol,
		SCIP_Real *	dualsol,
		SCIP_Real *	activity,
		SCIP_Real *	redcost
	)

gets primal and dual solution vectors for feasible LPs

gets primal and dual solution vectors

Parameters

lpi	LP interface structure
objval	stores the objective value, may be NULL if not needed
primsol	primal solution vector, may be NULL if not needed
dualsol	dual solution vector, may be NULL if not needed
activity	row activity vector, may be NULL if not needed
redcost	reduced cost vector, may be NULL if not needed

Definition at line 2652 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_CONDRET, SCIP_ALLOC, SCIP_CALL, SCIP_INVALIDDATA, SCIP_LPERROR, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIPABORT, SCIPdebugMessage, SCIPerrorMessage, and SCIPmessagePrintWarning().

SCIP_RETCODE SCIPlpiGetPrimalRay	(	SCIP_LPI *	lpi,
		SCIP_Real *	ray
	)

gets primal ray for unbounded LPs

Unbounded ray (NULL returned if none/wrong). Up to user to use delete [] on these arrays.

Parameters

lpi	LP interface structure
ray	primal ray

Definition at line 2696 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, SCIP_LPERROR, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIPdebugMessage, SCIPerrorMessage, and SCIPmessagePrintWarning().

SCIP_RETCODE SCIPlpiGetDualfarkas	(	SCIP_LPI *	lpi,
		SCIP_Real *	dualfarkas
	)

gets dual Farkas proof for infeasibility

gets dual farkas proof for infeasibility

Infeasibility ray (NULL returned if none/wrong). Up to user to use delete [] on these arrays.

Parameters

lpi	LP interface structure
dualfarkas	dual Farkas row multipliers

Definition at line 2721 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_RETURN, SCIP_LPERROR, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIPdebugMessage, and SCIPmessagePrintWarning().

SCIP_RETCODE SCIPlpiGetIterations	(	SCIP_LPI *	lpi,
		int *	iterations
	)

gets the number of LP iterations of the last solve call

Parameters

lpi	LP interface structure
iterations	pointer to store the number of iterations of the last solve call

Definition at line 2753 of file lpi_clp.cpp.

References NULL, QS_CONDRET, SCIP_OKAY, SCIP_PLUGINNOTFOUND, and SCIPdebugMessage.

SCIP_RETCODE SCIPlpiGetRealSolQuality	(	SCIP_LPI *	lpi,
		SCIP_LPSOLQUALITY	qualityindicator,
		SCIP_Real *	quality
	)

gets information about the quality of an LP solution

Such information is usually only available, if also a (maybe not optimal) solution is available. The LPI should return SCIP_INVALID for quality, if the requested quantity is not available.

gets information about the quality of an LP solution

Such information is usually only available, if also a (maybe not optimal) solution is available. The LPI should return SCIP_INVALID for quality, if the requested quality is not available.

Parameters

lpi	LP interface structure
qualityindicator	indicates which quality should be returned
quality	pointer to store quality number

Definition at line 2771 of file lpi_clp.cpp.

References CHECK_ZERO, NULL, SCIP_INVALID, SCIP_INVALIDDATA, SCIP_LPSOLQUALITY_ESTIMCONDITION, SCIP_LPSOLQUALITY_EXACTCONDITION, SCIP_OKAY, SCIPdebugMessage, and SCIPerrorMessage.

Referenced by SCIPlpiIsStable().

SCIP_RETCODE SCIPlpiGetBase	(	SCIP_LPI *	lpi,
		int *	cstat,
		int *	rstat
	)

gets current basis status for columns and rows; arrays must be large enough to store the basis status

Parameters

lpi	LP interface structure
cstat	array to store column basis status, or NULL
rstat	array to store row basis status, or NULL

Definition at line 2798 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_CONDRET, SCIP_BASESTAT_BASIC, SCIP_BASESTAT_LOWER, SCIP_BASESTAT_UPPER, SCIP_BASESTAT_ZERO, SCIP_CALL, SCIP_INVALIDDATA, SCIP_LPERROR, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIP_Real, SCIPABORT, SCIPdebugMessage, and SCIPerrorMessage.

Referenced by SCIPlpiGetState().

SCIP_RETCODE SCIPlpiSetBase	(	SCIP_LPI *	lpi,
		int *	cstat,
		int *	rstat
	)

sets current basis status for columns and rows

Whats changed since last solve. Is only used when startFinishOptions used in dual or primal. Bit 1 - number of rows/columns has not changed (so work arrays valid) 2 - matrix has not changed 4 - if matrix has changed only by adding rows 8 - if matrix has changed only by adding columns 16 - row lbs not changed 32 - row ubs not changed 64 - column objective not changed 128 - column lbs not changed 256 - column ubs not changed 512 - basis not changed (up to user to set this to 0) top bits may be used internally

Parameters

lpi	LP interface structure
cstat	array with column basis status
rstat	array with row basis status

Definition at line 2886 of file lpi_clp.cpp.

References CHECK_ZERO, EPSEQ, FALSE, MOSEK_CALL, NULL, QS_RETURN, SCIP_ALLOC, SCIP_BASESTAT_BASIC, SCIP_BASESTAT_LOWER, SCIP_BASESTAT_UPPER, SCIP_BASESTAT_ZERO, SCIP_CALL, SCIP_INVALIDDATA, SCIP_LPERROR, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIPABORT, SCIPdebugMessage, SCIPerrorMessage, and SOPLEX_TRY.

Referenced by SCIPlpiSetState().

SCIP_RETCODE SCIPlpiGetBasisInd	(	SCIP_LPI *	lpi,
		int *	bind
	)

returns the indices of the basic columns and rows; basic column n gives value n, basic row m gives value -1-m

Parameters

lpi	LP interface structure
bind	pointer to store basis indices ready to keep number of rows entries

Definition at line 3002 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_CONDRET, SCIP_ALLOC, SCIP_BASESTAT_BASIC, SCIP_BASESTAT_LOWER, SCIP_BASESTAT_UPPER, SCIP_BASESTAT_ZERO, SCIP_CALL, SCIP_CALL_QUIET, SCIP_OKAY, SCIP_PLUGINNOTFOUND, and SCIPdebugMessage.

Referenced by SCIPlpiGetBInvRow().

SCIP_RETCODE SCIPlpiGetBInvRow	(	SCIP_LPI *	lpi,
		int	row,
		SCIP_Real *	coef,
		int *	inds,
		int *	ninds
	)

get dense row of inverse basis matrix B^-1

Note: The LP interface defines slack variables to have coefficient +1. This means that if, internally, the LP solver uses a -1 coefficient, then rows associated with slacks variables whose coefficient is -1, should be negated; see also the explanation in lpi.h.

get dense row of inverse basis matrix B^-1

Note: The LP interface defines slack variables to have coefficient +1. This means that if, internally, the LP solver uses a -1 coefficient, then rows associated with slacks variables whose coefficient is -1, should be negated; see also the explanation in lpi.h.

get dense row of inverse basis matrix B^-1

Note: The LP interface defines slack variables to have coefficient +1. This means that if, internally, the LP solver uses a -1 coefficient, then rows associated with slacks variables whose coefficient is -1, should be negated; see also the explanation in lpi.h.

get row of inverse basis matrix B^-1

Note: The LP interface defines slack variables to have coefficient +1. This means that if, internally, the LP solver uses a -1 coefficient, then rows associated with slacks variables whose coefficient is -1, should be negated; see also the explanation in lpi.h.

get dense row of inverse basis matrix B^-1

Note: The LP interface defines slack variables to have coefficient +1. This means that if, internally, the LP solver uses a -1 coefficient, then rows associated with slacks variables whose coefficient is -1, should be negated; see also the explanation in lpi.h.

get dense row of inverse basis matrix B^-1

Note: The LP interface defines slack variables to have coefficient +1. This means that if, internally, the LP solver uses a -1 coefficient, then rows associated with slacks variables whose coefficient is -1, should be negated; see also the explanation in lpi.h.

Parameters

lpi	LP interface structure
row	row number
coef	pointer to store the coefficients of the row
inds	array to store the non-zero indices
ninds	pointer to store the number of non-zero indices (-1: if we do not store sparsity informations)

Definition at line 3054 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_RETURN, SCIP_ALLOC, SCIP_CALL, SCIP_CALL_QUIET, SCIP_LPERROR, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIPdebugMessage, SCIPlpiGetBasisInd(), SCIPmessagePrintWarning(), and SVECTOR.

Referenced by SCIPlpiGetBInvARow().

SCIP_RETCODE SCIPlpiGetBInvCol	(	SCIP_LPI *	lpi,
		int	c,
		SCIP_Real *	coef,
		int *	inds,
		int *	ninds
	)

get dense column of inverse basis matrix B^-1

Note: The LP interface defines slack variables to have coefficient +1. This means that if, internally, the LP solver uses a -1 coefficient, then rows associated with slacks variables whose coefficient is -1, should be negated; see also the explanation in lpi.h.

get dense column of inverse basis matrix B^-1

Note: The LP interface defines slack variables to have coefficient +1. This means that if, internally, the LP solver uses a -1 coefficient, then rows associated with slacks variables whose coefficient is -1, should be negated; see also the explanation in lpi.h.

get dense column of inverse basis matrix B^-1

Note: The LP interface defines slack variables to have coefficient +1. This means that if, internally, the LP solver uses a -1 coefficient, then rows associated with slacks variables whose coefficient is -1, should be negated; see also the explanation in lpi.h.

get column of inverse basis matrix B^-1

Note: The LP interface defines slack variables to have coefficient +1. This means that if, internally, the LP solver uses a -1 coefficient, then rows associated with slacks variables whose coefficient is -1, should be negated; see also the explanation in lpi.h.

get dense column of inverse basis matrix B^-1

Note: The LP interface defines slack variables to have coefficient +1. This means that if, internally, the LP solver uses a -1 coefficient, then rows associated with slacks variables whose coefficient is -1, should be negated; see also the explanation in lpi.h.

get dense column of inverse basis matrix B^-1

Note: The LP interface defines slack variables to have coefficient +1. This means that if, internally, the LP solver uses a -1 coefficient, then rows associated with slacks variables whose coefficient is -1, should be negated; see also the explanation in lpi.h.

Parameters

lpi	LP interface structure
c	column number of B^-1; this is NOT the number of the column in the LP; you have to call SCIPlpiGetBasisInd() to get the array which links the B^-1 column numbers to the row and column numbers of the LP! c must be between 0 and nrows-1, since the basis has the size nrows * nrows
coef	pointer to store the coefficients of the column
inds	array to store the non-zero indices
ninds	pointer to store the number of non-zero indices (-1: if we do not store sparsity informations)

Definition at line 3089 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, SCIP_ALLOC, SCIP_CALL, SCIP_CALL_QUIET, SCIP_LPERROR, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIPdebugMessage, SCIPerrorMessage, and SVECTOR.

SCIP_RETCODE SCIPlpiGetBInvARow	(	SCIP_LPI *	lpi,
		int	r,
		const SCIP_Real *	binvrow,
		SCIP_Real *	coef,
		int *	inds,
		int *	ninds
	)

get dense row of inverse basis matrix times constraint matrix B^-1 * A

Note: The LP interface defines slack variables to have coefficient +1. This means that if, internally, the LP solver uses a -1 coefficient, then rows associated with slacks variables whose coefficient is -1, should be negated; see also the explanation in lpi.h.

get dense row of inverse basis matrix times constraint matrix B^-1 * A

Note: The LP interface defines slack variables to have coefficient +1. This means that if, internally, the LP solver uses a -1 coefficient, then rows associated with slacks variables whose coefficient is -1, should be negated; see also the explanation in lpi.h.

get dense row of inverse basis matrix times constraint matrix B^-1 * A

Note: The LP interface defines slack variables to have coefficient +1. This means that if, internally, the LP solver uses a -1 coefficient, then rows associated with slacks variables whose coefficient is -1, should be negated; see also the explanation in lpi.h.

get row of inverse basis matrix times constraint matrix B^-1 * A

Note: The LP interface defines slack variables to have coefficient +1. This means that if, internally, the LP solver uses a -1 coefficient, then rows associated with slacks variables whose coefficient is -1, should be negated; see also the explanation in lpi.h.

get dense row of inverse basis matrix times constraint matrix B^-1 * A

Note: The LP interface defines slack variables to have coefficient +1. This means that if, internally, the LP solver uses a -1 coefficient, then rows associated with slacks variables whose coefficient is -1, should be negated; see also the explanation in lpi.h.

get dense row of inverse basis matrix times constraint matrix B^-1 * A

Note: The LP interface defines slack variables to have coefficient +1. This means that if, internally, the LP solver uses a -1 coefficient, then rows associated with slacks variables whose coefficient is -1, should be negated; see also the explanation in lpi.h.

Parameters

lpi	LP interface structure
r	row number
binvrow	row in (A_B)^-1 from prior call to SCIPlpiGetBInvRow(), or NULL
coef	vector to return coefficients
inds	array to store the non-zero indices
ninds	pointer to store the number of non-zero indices (-1: if we do not store sparsity informations)

Definition at line 3127 of file lpi_clp.cpp.

References CHECK_ZERO, MOSEK_CALL, NULL, QS_CONDRET, SCIP_ALLOC, SCIP_CALL, SCIP_CALL_QUIET, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIP_Real, SCIPdebugMessage, SCIPlpiGetBInvRow(), and SVECTOR.

SCIP_RETCODE SCIPlpiGetBInvACol	(	SCIP_LPI *	lpi,
		int	c,
		SCIP_Real *	coef,
		int *	inds,
		int *	ninds
	)