Detailed Description

LP interface for HiGHS 1.4 and higher.

Author: Ambros Gleixner; Julian Hall; Alexander Hoen; Gioni Mexi

This is an implementation of SCIP's LP interface for the open-source solver HiGHS.

The most important open todos are:

tune pricing strategy
tune and activate primal simplex
tune and activate parallel dual simplex

Definition in file lpi_highs.cpp.

#include <cassert>
#include <cstdlib>
#include <string>
#include <vector>
#include <Highs.h>
#include <lp_data/HighsLpUtils.h>
#include "lpi/lpi.h"
#include "scip/bitencode.h"
#include "scip/pub_message.h"
#include "scip/type_lp.h"

Go to the source code of this file.

Data Structures
class	HighsSCIP

struct	SCIP_LPi

struct	SCIP_LPiState

Macros
#define	HIGHS_relDiff(val1, val2) ( ((val1)-(val2))/(MAX3(1.0,REALABS(val1),REALABS(val2))) )

#define	HIGHS_CALL(x)

#define	HIGHS_CALL_WITH_WARNING(x)

#define	COLS_PER_PACKET SCIP_DUALPACKETSIZE

#define	ROWS_PER_PACKET SCIP_DUALPACKETSIZE

Typedefs
typedef SCIP_DUALPACKET	COLPACKET

typedef SCIP_DUALPACKET	ROWPACKET

Functions
static SCIP_RETCODE	ensureCstatMem (SCIP_LPI *lpi, int num)

static SCIP_RETCODE	ensureRstatMem (SCIP_LPI *lpi, int num)

static int	colpacketNum (int ncols)

static int	rowpacketNum (int nrows)

static void	lpistatePack (SCIP_LPISTATE lpistate, const int cstat, const int *rstat)

static void	lpistateUnpack (const SCIP_LPISTATE lpistate, int cstat, int *rstat)

static SCIP_RETCODE	lpistateCreate (SCIP_LPISTATE *lpistate, BMS_BLKMEM blkmem, int ncols, int nrows)

static void	lpistateFree (SCIP_LPISTATE *lpistate, BMS_BLKMEM blkmem)

static void	invalidateSolution (SCIP_LPI *lpi)

static HighsBasisStatus	basestatToHighsBasisStatus (const int &stat)

static std::string	simplexStrategyToString (const int &strategy)

static SCIP_RETCODE	checkMatrixValue (SCIP_LPI *lpi, SCIP_Real value)

static SCIP_RETCODE	lpiSolve (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, const int ind, const 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	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	SCIPlpiGetObjsen (SCIP_LPI lpi, SCIP_OBJSEN objsen)

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, const int cstat, const 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)

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

SCIP_RETCODE	SCIPlpiSetState (SCIP_LPI lpi, BMS_BLKMEM blkmem, const 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)

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

SCIP_RETCODE	SCIPlpiSetNorms (SCIP_LPI lpi, BMS_BLKMEM blkmem, const 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)

SCIP_RETCODE	SCIPlpiInterrupt (SCIP_LPI *lpi, SCIP_Bool interrupt)

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)

Variables
int	nsolvecalls = 0

Miscellaneous Methods
static char	highsname [30]

static char	highsdesc [200]

const char *	SCIPlpiGetSolverName (void)

const char *	SCIPlpiGetSolverDesc (void)

void *	SCIPlpiGetSolverPointer (SCIP_LPI *lpi)

SCIP_RETCODE	SCIPlpiSetIntegralityInformation (SCIP_LPI lpi, int ncols, int intInfo)

SCIP_Bool	SCIPlpiHasPrimalSolve (void)

SCIP_Bool	SCIPlpiHasDualSolve (void)

SCIP_Bool	SCIPlpiHasBarrierSolve (void)

Macro Definition Documentation

◆ HIGHS_relDiff

#define HIGHS_relDiff	(	val1,
		val2
	)	( ((val1)-(val2))/(MAX3(1.0,REALABS(val1),REALABS(val2))) )

Definition at line 78 of file lpi_highs.cpp.

◆ HIGHS_CALL

#define HIGHS_CALL ( x )

Value:

                        do                                                                                     \
                        {                                                                                      \
                           try                                                                                 \
                           {                                                                                   \
                              HighsStatus _restat_; /*lint -e{506,774}*/                                       \
                              (_restat_ = (x));                                                                \
                              if( _restat_ == HighsStatus::kWarning )                                          \
                              {                                                                                \
                                 SCIPerrorMessage("Warning in HiGHS function call\n");                         \
                                 return SCIP_LPERROR;                                                          \
                              }                                                                                \
                              else if( _restat_ != HighsStatus::kOk )                                          \
                              {                                                                                \
                                 SCIPerrorMessage("Error in HiGHS function call\n");                           \
                                 return SCIP_LPERROR;                                                          \
                              }                                                                                \
                           }                                                                                   \
                           catch( std::exception & E )                                                         \
                           {                                                                                   \
                              std::string s = E.what();                                                        \
                              SCIPerrorMessage( "HiGHS threw an exception: %s\n", s.c_str());                  \
                              return SCIP_LPERROR;                                                             \
                           }                                                                                   \
                           catch( ... )                                                                        \
                           {                                                                                   \
                              SCIPerrorMessage("HiGHS threw an unidentified exception\n");                     \
                              return SCIP_LPERROR;                                                             \
                           }                                                                                   \
                        }                                                                                      \
                        while( FALSE )

Macro for a single HiGHS call for which exceptions have to be caught. We make no distinction between different exception types, e.g., between memory allocation and other exceptions. Additionally, we check if HiGHS returns kOk as status and return an LP error if not.

Definition at line 84 of file lpi_highs.cpp.

◆ HIGHS_CALL_WITH_WARNING

#define HIGHS_CALL_WITH_WARNING ( x )

Value:

                        do                                                                        \
                        {                                                                                      \
                           try                                                                                 \
                           {                                                                                   \
                              HighsStatus _restat_; /*lint -e{506,774}*/                                       \
                              (_restat_ = (x));                                                                \
                              if( _restat_ != HighsStatus::kOk && _restat_ != HighsStatus::kWarning )          \
                              {                                                                                \
                                 SCIPerrorMessage("Error in HiGHS in function call (returned %d)\n",           \
                                    int(_restat_));                                                            \
                                 return SCIP_LPERROR;                                                          \
                              }                                                                                \
                           }                                                                                   \
                           catch( std::exception & E )                                                         \
                           {                                                                                   \
                              std::string s = E.what();                                                        \
                              SCIPerrorMessage( "HiGHS threw an exception: %s\n", s.c_str());                  \
                              return SCIP_LPERROR;                                                             \
                           }                                                                                   \
                           catch( ... )                                                                        \
                           {                                                                                   \
                              SCIPerrorMessage("HiGHS threw an unidentified exception\n");                     \
                              return SCIP_LPERROR;                                                             \
                           }                                                                                   \
                        }                                                                                      \
                        while( FALSE )

A relaxed version of HIGHS_CALL that accepts status kWarning.

Definition at line 116 of file lpi_highs.cpp.

◆ COLS_PER_PACKET

#define COLS_PER_PACKET SCIP_DUALPACKETSIZE

each column needs two bits of information (basic/on_lower/on_upper)

Definition at line 188 of file lpi_highs.cpp.

◆ ROWS_PER_PACKET

#define ROWS_PER_PACKET SCIP_DUALPACKETSIZE

each row needs two bit of information (basic/on_lower/on_upper)

Definition at line 190 of file lpi_highs.cpp.

Typedef Documentation

◆ COLPACKET

typedef SCIP_DUALPACKET COLPACKET

Definition at line 187 of file lpi_highs.cpp.

◆ ROWPACKET

typedef SCIP_DUALPACKET ROWPACKET

Definition at line 189 of file lpi_highs.cpp.

Function Documentation

◆ ensureCstatMem()

static SCIP_RETCODE ensureCstatMem	(	SCIP_LPI *	lpi,
		int	num
	)

static

resizes cstat array to have at least num entries

Parameters

lpi	LP interface structure
num	minimal number of entries in array

Definition at line 207 of file lpi_highs.cpp.

References BMSreallocMemoryArray, SCIP_LPi::cstat, SCIP_LPi::cstatsize, MAX, NULL, SCIP_ALLOC, SCIP_OKAY, and SCIPdebugMessage.

Referenced by SCIPlpiGetState(), and SCIPlpiSetState().

◆ ensureRstatMem()

static SCIP_RETCODE ensureRstatMem	(	SCIP_LPI *	lpi,
		int	num
	)

static

resizes rstat array to have at least num entries

Parameters

lpi	LP interface structure
num	minimal number of entries in array

Definition at line 230 of file lpi_highs.cpp.

References BMSreallocMemoryArray, MAX, NULL, SCIP_LPi::rstat, SCIP_LPi::rstatsize, SCIP_ALLOC, SCIP_OKAY, and SCIPdebugMessage.

Referenced by SCIPlpiGetState(), and SCIPlpiSetState().

◆ colpacketNum()

static int colpacketNum ( int ncols )

static

returns the number of packets needed to store column packet information

Parameters

ncols number of columns to store

Definition at line 258 of file lpi_highs.cpp.

References COLS_PER_PACKET.

Referenced by lpistateCreate(), and lpistateFree().

◆ rowpacketNum()

static int rowpacketNum ( int nrows )

static

returns the number of packets needed to store row packet information

Parameters

nrows number of rows to store

Definition at line 267 of file lpi_highs.cpp.

References ROWS_PER_PACKET.

Referenced by lpistateCreate(), and lpistateFree().

◆ lpistatePack()

static void lpistatePack	(	SCIP_LPISTATE *	lpistate,
		const int *	cstat,
		const int *	rstat
	)

static

store row and column basis status in a packed LPi state object

Parameters

lpistate	pointer to LPi state data
cstat	basis status of columns in unpacked format
rstat	basis status of rows in unpacked format

Definition at line 276 of file lpi_highs.cpp.

References SCIP_LPiState::ncols, SCIP_LPiState::nrows, NULL, SCIP_LPiState::packcstat, SCIP_LPiState::packrstat, and SCIPencodeDualBit().

Referenced by SCIPlpiGetState().

◆ lpistateUnpack()

static void lpistateUnpack	(	const SCIP_LPISTATE *	lpistate,
		int *	cstat,
		int *	rstat
	)

static

unpacks row and column basis status from a packed LPi state object

Parameters

lpistate	pointer to LPi state data
cstat	buffer for storing basis status of columns in unpacked format
rstat	buffer for storing basis status of rows in unpacked format

Definition at line 292 of file lpi_highs.cpp.

References SCIP_LPiState::ncols, SCIP_LPiState::nrows, NULL, SCIP_LPiState::packcstat, SCIP_LPiState::packrstat, and SCIPdecodeDualBit().

Referenced by SCIPlpiSetState().

◆ lpistateCreate()

static SCIP_RETCODE lpistateCreate	(	SCIP_LPISTATE **	lpistate,
		BMS_BLKMEM *	blkmem,
		int	ncols,
		int	nrows
	)

static

creates LPi state information object

Parameters

lpistate	pointer to LPi state
blkmem	block memory
ncols	number of columns to store
nrows	number of rows to store

Definition at line 308 of file lpi_highs.cpp.

References BMSallocBlockMemory, BMSallocBlockMemoryArray, colpacketNum(), NULL, rowpacketNum(), SCIP_ALLOC, and SCIP_OKAY.

Referenced by SCIPlpiGetState().

◆ lpistateFree()

static void lpistateFree	(	SCIP_LPISTATE **	lpistate,
		BMS_BLKMEM *	blkmem
	)

static

frees LPi state information

Parameters

lpistate	pointer to LPi state information (like basis information)
blkmem	block memory

Definition at line 332 of file lpi_highs.cpp.

References BMSfreeBlockMemory, BMSfreeBlockMemoryArray, colpacketNum(), NULL, and rowpacketNum().

Referenced by SCIPlpiFreeState().

◆ invalidateSolution()

static void invalidateSolution ( SCIP_LPI * lpi )

static

marks the current LP to be unsolved

Parameters

lpi	LP interface structure

Definition at line 356 of file lpi_highs.cpp.

References FALSE, NULL, and SCIP_LPi::solved.

Referenced by SCIPlpiAddCols(), SCIPlpiAddRows(), SCIPlpiChgBounds(), SCIPlpiChgCoef(), SCIPlpiChgObj(), SCIPlpiChgObjsen(), SCIPlpiChgSides(), SCIPlpiClear(), SCIPlpiCreate(), SCIPlpiDelCols(), SCIPlpiDelColset(), SCIPlpiDelRows(), SCIPlpiDelRowset(), SCIPlpiScaleCol(), and SCIPlpiScaleRow().

◆ basestatToHighsBasisStatus()

static HighsBasisStatus basestatToHighsBasisStatus ( const int & stat )

static

converts basis statuses

Definition at line 366 of file lpi_highs.cpp.

References SCIP_BASESTAT_BASIC, SCIP_BASESTAT_LOWER, SCIP_BASESTAT_UPPER, SCIP_BASESTAT_ZERO, and SCIPerrorMessage.

Referenced by SCIPlpiSetBase().

◆ simplexStrategyToString()

static std::string simplexStrategyToString ( const int & strategy )

static

returns a string representation of the simplex strategy parameter

Definition at line 389 of file lpi_highs.cpp.

Referenced by lpiSolve().

◆ checkMatrixValue()

static SCIP_RETCODE checkMatrixValue	(	SCIP_LPI *	lpi,
		SCIP_Real	value
	)

static

checks that matrix values are within range defined by HiGHS parameters

Parameters

lpi	LP interface structure
value	value of coefficient

Definition at line 412 of file lpi_highs.cpp.

References SCIP_LPi::highs, HIGHS_CALL, SCIP_OKAY, and SCIP_Real.

Referenced by SCIPlpiAddCols(), SCIPlpiAddRows(), SCIPlpiChgCoef(), and SCIPlpiLoadColLP().

◆ lpiSolve()

static SCIP_RETCODE lpiSolve ( SCIP_LPI * lpi )

static

calls HiGHS to solve the LP with given settings

Parameters

lpi	LP interface structure

Definition at line 433 of file lpi_highs.cpp.

References SCIP_LPi::fromscratch, SCIP_LPi::highs, HIGHS_CALL, HIGHS_CALL_WITH_WARNING, lpiSolve(), nsolvecalls, NULL, SCIP_CALL, SCIP_LPERROR, SCIP_OKAY, SCIPdebugMessage, SCIPerrorMessage, simplexStrategyToString(), SCIP_LPi::solved, and TRUE.

Referenced by lpiSolve(), SCIPlpiSolveDual(), and SCIPlpiSolvePrimal().

Variable Documentation

◆ nsolvecalls

int nsolvecalls = 0

Definition at line 144 of file lpi_highs.cpp.

Referenced by lpiSolve().

◆ highsname

char highsname[30]

static

Definition at line 548 of file lpi_highs.cpp.

Referenced by SCIPlpiGetSolverName().

◆ highsdesc

char highsdesc[200]

static

Definition at line 549 of file lpi_highs.cpp.

Referenced by SCIPlpiGetSolverDesc().

SCIP

Detailed Description

Data Structures

Macros

Typedefs

Functions

Variables

Miscellaneous Methods

Macro Definition Documentation

◆ HIGHS_relDiff

◆ HIGHS_CALL

◆ HIGHS_CALL_WITH_WARNING

◆ COLS_PER_PACKET

◆ ROWS_PER_PACKET

Typedef Documentation

◆ COLPACKET

◆ ROWPACKET

Function Documentation

◆ ensureCstatMem()

◆ ensureRstatMem()

◆ colpacketNum()

◆ rowpacketNum()

◆ lpistatePack()

◆ lpistateUnpack()

◆ lpistateCreate()

◆ lpistateFree()

◆ invalidateSolution()

◆ basestatToHighsBasisStatus()

◆ simplexStrategyToString()

◆ checkMatrixValue()

◆ lpiSolve()

Variable Documentation

◆ nsolvecalls

◆ highsname

◆ highsdesc