Scippy

SCIP

Solving Constraint Integer Programs

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 )
SCIP_VAR ** x
Definition: circlepacking.c:63
#define FALSE
Definition: def.h:94
@ SCIP_LPERROR
Definition: type_retcode.h:49

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

Definition at line 187 of file lpi_highs.cpp.

◆ 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
lpiLP interface structure
numminimal 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
lpiLP interface structure
numminimal 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
ncolsnumber 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
nrowsnumber 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
lpistatepointer to LPi state data
cstatbasis status of columns in unpacked format
rstatbasis 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
lpistatepointer to LPi state data
cstatbuffer for storing basis status of columns in unpacked format
rstatbuffer 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
lpistatepointer to LPi state
blkmemblock memory
ncolsnumber of columns to store
nrowsnumber 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
lpistatepointer to LPi state information (like basis information)
blkmemblock 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

◆ 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
lpiLP interface structure
valuevalue 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
lpiLP 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().