Detailed Description

LP interface for SoPlex.

Author: Matthias Miltenberger; Ambros Gleixner

This is an implementation of SCIP's LP interface for SoPlex.

For debugging purposes, the SoPlex results can be double checked with CPLEX if SCIP_WITH_LPSCHECK is defined. This may yield false positives, since the LP is dumped to a file for transferring it to CPLEX, hence, precision may be lost.

Definition in file lpi_spx.cpp.

#include "scip/config.h"
#include "soplex.h"
#include "spxgithash.h"
#include "scip/pub_message.h"
#include <cassert>
#include "lpi/lpi.h"
#include "scip/bitencode.h"

Go to the source code of this file.

Data Structures
struct	SCIP_LPi
struct	SCIP_LPiState
struct	SCIP_LPiNorms

Macros
#define	STRONGBRANCH_RESTOREBASIS
#define	CHECK_SOPLEX_PARAM(x)
#define	SOPLEX_SUBVERSION 0
#define	SOPLEX_APIVERSION 0
#define	SOPLEX_VERBLEVEL 5
#define	NULL 0
#define	SOPLEX_TRY(messagehdlr, x)
#define	SOPLEX_TRY_ABORT(x)
#define	COLS_PER_PACKET SCIP_DUALPACKETSIZE
#define	ROWS_PER_PACKET SCIP_DUALPACKETSIZE

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)
Miscellaneous Methods
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)
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 , 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 *, 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 , 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
static SCIP_RETCODE	spxSolve (SCIP_LPI *lpi)
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)
static SCIP_RETCODE	lpiStrongbranch (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	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 , 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
static SCIP_Bool	fileExists (const char *filename)
SCIP_RETCODE	SCIPlpiReadLP (SCIP_LPI lpi, const char fname)
SCIP_RETCODE	SCIPlpiWriteLP (SCIP_LPI lpi, const char fname)

Variables
static const char	spxname [20] = {'S', 'o', 'P', 'l', 'e', 'x', ' ', SOPLEX_VERSION/100 + '0', '.', (SOPLEX_VERSION % 100)/10 + '0', '.', SOPLEX_VERSION % 10 + '0', '\0'}
static const char	spxdesc [200]

Macro Definition Documentation

◆ STRONGBRANCH_RESTOREBASIS

#define STRONGBRANCH_RESTOREBASIS

if defined then in SCIPlpiStrongbranch() we restore the basis after the down branch and after the up branch; if false only after the end of a strong branching phase, which however seems to mostly increase strong branching time and iterations

Definition at line 39 of file lpi_spx.cpp.

◆ CHECK_SOPLEX_PARAM

#define CHECK_SOPLEX_PARAM ( x )

Value:

   if( !x )                                                                             \
   {                                                                                    \
      SCIPmessagePrintWarning(_messagehdlr, "SoPlex: unsupported parameter value\n");   \
   }

Definition at line 79 of file lpi_spx.cpp.

◆ SOPLEX_SUBVERSION

#define SOPLEX_SUBVERSION 0

Definition at line 102 of file lpi_spx.cpp.

Referenced by SCIPlpiGetNNonz().

◆ SOPLEX_APIVERSION

#define SOPLEX_APIVERSION 0

Definition at line 106 of file lpi_spx.cpp.

◆ SOPLEX_VERBLEVEL

#define SOPLEX_VERBLEVEL 5

verbosity level for LPINFO

Definition at line 132 of file lpi_spx.cpp.

Referenced by lpiStrongbranch(), SCIPlpiCreate(), SCIPlpiExactCreate(), spxSolve(), and spxSolve().

◆ NULL

#define NULL 0

Definition at line 142 of file lpi_spx.cpp.

◆ SOPLEX_TRY

#define SOPLEX_TRY	(		messagehdlr,
			x )

Value:

   do                                  \
   {                                                                    \
      try                                                               \
      {                                                                 \
         (x);                                                           \
      }                                                                 \
      catch( const SPxMemoryException& E )                              \
      {                                                                 \
         std::string s = E.what();                                      \
         SCIPerrorMessage("SoPlex threw a memory exception: %s\n", s.c_str()); \
         return SCIP_ERROR;                                             \
      }                                                                 \
      catch( const SPxException& E )                                    \
      {                                                                 \
         std::string s = E.what();                                      \
         SCIPmessagePrintWarning((messagehdlr), "SoPlex threw an exception: %s\n", s.c_str()); \
         return SCIP_LPERROR;                                           \
      }                                                                 \
   }                                                                    \
   while( FALSE )

Macro for a single SoPlex call for which exceptions have to be catched - return an LP error. We make no distinction between different exception types, e.g., between memory allocation and other exceptions.

Definition at line 153 of file lpi_spx.cpp.

Referenced by SCIPlpiChgCoef(), SCIPlpiChgObjsen(), SCIPlpiClear(), SCIPlpiCreate(), SCIPlpiDelCols(), SCIPlpiDelColset(), SCIPlpiDelRows(), SCIPlpiDelRowset(), SCIPlpiReadState(), SCIPlpiSetBase(), and SCIPlpiWriteState().

◆ SOPLEX_TRY_ABORT

#define SOPLEX_TRY_ABORT ( x )

Value:

   do                                         \
   {                                                                    \
      try                                                               \
      {                                                                 \
         (x);                                                           \
      }                                                                 \
      catch( const SPxException& E )                                    \
      {                                                                 \
         std::string s = E.what();                                      \
         SCIPerrorMessage("SoPlex threw an exception: %s\n", s.c_str()); \
         abort();                                                       \
      }                                                                 \
   }                                                                    \
   while( FALSE )

Definition at line 198 of file lpi_spx.cpp.

◆ COLS_PER_PACKET

#define COLS_PER_PACKET SCIP_DUALPACKETSIZE

Definition at line 761 of file lpi_spx.cpp.

◆ ROWS_PER_PACKET

#define ROWS_PER_PACKET SCIP_DUALPACKETSIZE

Definition at line 763 of file lpi_spx.cpp.

Function Documentation

◆ ensureCstatMem()

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 807 of file lpi_spx.cpp.

References assert(), BMSreallocMemoryArray, SCIP_LPi::cstat, SCIP_LPi::cstatsize, MAX, NULL, SCIP_ALLOC, and SCIP_OKAY.

Referenced by SCIPlpiGetState(), and SCIPlpiSetState().

◆ ensureRstatMem()

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 829 of file lpi_spx.cpp.

References assert(), BMSreallocMemoryArray, MAX, NULL, SCIP_LPi::rstat, SCIP_LPi::rstatsize, SCIP_ALLOC, and SCIP_OKAY.

Referenced by SCIPlpiGetState(), and SCIPlpiSetState().

◆ colpacketNum()

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 858 of file lpi_spx.cpp.

References COLS_PER_PACKET.

Referenced by lpistateCreate(), and lpistateFree().

◆ rowpacketNum()

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 867 of file lpi_spx.cpp.

References ROWS_PER_PACKET.

Referenced by lpistateCreate(), and lpistateFree().

◆ lpistatePack()

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 876 of file lpi_spx.cpp.

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

Referenced by SCIPlpiGetState().

◆ lpistateUnpack()

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 892 of file lpi_spx.cpp.

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

Referenced by SCIPlpiSetState().

◆ lpistateCreate()

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 908 of file lpi_spx.cpp.

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

Referenced by SCIPlpiGetState().

◆ lpistateFree()

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 932 of file lpi_spx.cpp.

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

Referenced by SCIPlpiFreeState().

◆ invalidateSolution()

void invalidateSolution ( SCIP_LPI * lpi )

static

marks the current LP to be unsolved

Definition at line 959 of file lpi_spx.cpp.

References assert(), FALSE, NULL, and SCIP_LPi::solved.

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

◆ spxSolve()

SCIP_RETCODE spxSolve ( SCIP_LPI * lpi )

static

solves LP – used for both, primal and dual simplex, because SoPlex doesn't distinct the two cases

Parameters

lpi	LP interface structure

Definition at line 2388 of file lpi_spx.cpp.

References assert(), invalidateSolution(), SCIP_LPi::messagehdlr, NULL, SCIP_LPERROR, SCIP_OKAY, SCIPdebugMessage, SCIPmessagePrintWarning(), SCIP_LPi::solved, SOPLEX_VERBLEVEL, SCIP_LPi::spx, TRUE, and x.

Referenced by SCIPlpiSolveDual(), and SCIPlpiSolvePrimal().

◆ lpiStrongbranch()

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

static

performs strong branching iterations on one arbitrary candidate

Parameters

lpi	LP interface structure
col	column to apply strong branching on
psol	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 2533 of file lpi_spx.cpp.

References assert(), EPSCEIL, EPSFLOOR, FALSE, NULL, SCIP_Bool, SCIP_LPERROR, SCIP_OKAY, SCIP_Real, SCIPdebugMessage, SOPLEX_VERBLEVEL, SCIP_LPi::spx, and TRUE.

Referenced by SCIPlpiStrongbranchesFrac(), SCIPlpiStrongbranchesInt(), SCIPlpiStrongbranchFrac(), and SCIPlpiStrongbranchInt().

◆ fileExists()

SCIP_Bool fileExists ( const char * filename )

static

returns whether the given file exists

Parameters

filename file name

Definition at line 4634 of file lpi_spx.cpp.

References FALSE, NULL, SCIP_Bool, and TRUE.

Referenced by SCIPlpiReadLP().

Variable Documentation

◆ spxname

const char spxname[20] = {'S', 'o', 'P', 'l', 'e', 'x', ' ', SOPLEX_VERSION/100 + '0', '.', (SOPLEX_VERSION % 100)/10 + '0', '.', SOPLEX_VERSION % 10 + '0', '\0'}

static

Definition at line 979 of file lpi_spx.cpp.

Referenced by SCIPlpiExactGetSolverName(), and SCIPlpiGetSolverName().

◆ spxdesc

const char spxdesc[200]

static

Initial value:

=  {'L', 'i', 'n', 'e', 'a', 'r', ' ', 'p', 'r', 'o', 'g', 'r', 'a', 'm', 'm', 'i', 'n', 'g',
                                   ' ', 's', 'o', 'l', 'v', 'e', 'r', ' ' , 'd', 'e', 'v', 'e', 'l', 'o', 'p', 'e', 'd',
                                   ' ', 'a', 't', ' ', 'Z', 'u', 's', 'e', ' ', 'I', 'n', 's', 't', 'i', 't', 'u', 't', 'e',
                                   ' ', 'B', 'e', 'r', 'l', 'i', 'n', ' ', '(', 's', 'o', 'p', 'l', 'e', 'x', '.', 'z', 'i', 'b', '.', 'd', 'e', ')',
 
 
 
 
                                   ' ', '[', 'G', 'i', 't', 'H', 'a', 's', 'h', ':', ' ',
                                   getGitHash()[0], getGitHash()[1], getGitHash()[2], getGitHash()[3],
                                   getGitHash()[4], getGitHash()[5], getGitHash()[6], getGitHash()[7],
                                   ']', '\0'}

Definition at line 981 of file lpi_spx.cpp.

Referenced by SCIPlpiExactGetSolverDesc(), and SCIPlpiGetSolverDesc().

Detailed Description

Data Structures

Macros

Functions

Variables

Macro Definition Documentation

◆ STRONGBRANCH_RESTOREBASIS

◆ CHECK_SOPLEX_PARAM

◆ SOPLEX_SUBVERSION

◆ SOPLEX_APIVERSION

◆ SOPLEX_VERBLEVEL

◆ NULL

◆ SOPLEX_TRY

◆ SOPLEX_TRY_ABORT

◆ COLS_PER_PACKET

◆ ROWS_PER_PACKET

Function Documentation

◆ ensureCstatMem()

◆ ensureRstatMem()

◆ colpacketNum()

◆ rowpacketNum()

◆ lpistatePack()

◆ lpistateUnpack()

◆ lpistateCreate()

◆ lpistateFree()

◆ invalidateSolution()

◆ spxSolve()

◆ lpiStrongbranch()

◆ fileExists()

Variable Documentation

◆ spxname

◆ spxdesc