# SCIP

Solving Constraint Integer Programs

lpi.h File Reference

## Detailed Description

interface methods for specific LP solvers

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.

The basis status for (column) variables are as follows:

• If x_j = lb, then j is at its lower bound (SCIP_BASESTAT_LOWER).
• If x_j = ub, then j is at its lower bound (SCIP_BASESTAT_UPPER).
• If x_j is in the basis, it has SCIP_BASESTAT_BASIC status.
• If x_j is free and non-basic, it has SCIP_BASESTAT_ZERO status.

The basis status for (row) slack variables are:

• If (A * x)_i = lhs, then i is at its lower bound (SCIP_BASESTAT_LOWER).
• If (A * x)_i = rhs, then i is at its upper bound (SCIP_BASESTAT_UPPER).
• If the slack variable for row i is basic, it has SCIP_BASESTAT_BASIC status.

If the solvers use their status differently, the have to be corrected.

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.

The creation of a new LP should always be done in the following ways: Either one can use SCIPlpiLoadColLP() or one first adds empty columns or rows. Then the matrix entries can be added by adding columns and rows, respectively. It is an error, if matrix entries are added for rows or columns that have not been added before.

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)

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

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 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, 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)

LPi 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)

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, 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)

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)

## ◆ SCIPlpiGetSolverName()

 const char* SCIPlpiGetSolverName ( void )

gets name and version of LP solver

Definition at line 432 of file lpi_clp.cpp.

## ◆ SCIPlpiGetSolverDesc()

 const char* SCIPlpiGetSolverDesc ( void )

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

Definition at line 441 of file lpi_clp.cpp.

References SCIPlpiGetSolverPointer(), and spxdesc.

Referenced by SCIPcreate(), and SCIPlpiGetSolverName().

## ◆ SCIPlpiGetSolverPointer()

 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

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 449 of file lpi_clp.cpp.

Referenced by SCIPlpiGetSolverDesc().

## ◆ SCIPlpiSetIntegralityInformation()

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

pass integrality information about variables to the solver

pass integrality information to LP solver

Parameters
 lpi pointer to an LP interface structure ncols length of integrality array intInfo integrality array (0: continuous, 1: integer)

Definition at line 457 of file lpi_clp.cpp.

References NULL, SCIP_LPERROR, SCIP_OKAY, SCIPerrorMessage, SCIPlpiCreate(), and SCIP_LPi::spx.

Referenced by lpCopyIntegrality(), and SCIPlpiGetSolverPointer().

## ◆ SCIPlpiCreate()

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

creates an LP problem object

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 480 of file lpi_clp.cpp.

## ◆ SCIPlpiFree()

 SCIP_RETCODE SCIPlpiFree ( SCIP_LPI ** lpi )

deletes an LP problem object

Parameters
 lpi pointer to an LP interface structure

Definition at line 549 of file lpi_clp.cpp.

 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 583 of file lpi_clp.cpp.

Referenced by SCIPlpiFree().

 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 )

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

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 649 of file lpi_clp.cpp.

## ◆ SCIPlpiDelCols()

 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 716 of file lpi_clp.cpp.

Referenced by lpFlushDelCols(), SCIPlpiAddCols(), and SCIPlpiClear().

## ◆ SCIPlpiDelColset()

 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

deletes columns from 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 747 of file lpi_clp.cpp.

Referenced by lpDelColset(), and SCIPlpiDelCols().

 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 )

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

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 793 of file lpi_clp.cpp.

## ◆ SCIPlpiDelRows()

 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 855 of file lpi_clp.cpp.

Referenced by lpFlushDelRows(), SCIPlpiAddRows(), and SCIPlpiClear().

## ◆ SCIPlpiDelRowset()

 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 887 of file lpi_clp.cpp.

Referenced by lpDelRowset(), and SCIPlpiDelRows().

## ◆ SCIPlpiClear()

 SCIP_RETCODE SCIPlpiClear ( SCIP_LPI * lpi )

clears the whole LP

Parameters
 lpi LP interface structure

Definition at line 933 of file lpi_clp.cpp.

## ◆ SCIPlpiChgBounds()

 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 952 of file lpi_clp.cpp.

## ◆ SCIPlpiChgSides()

 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 1028 of file lpi_clp.cpp.

## ◆ SCIPlpiChgCoef()

 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 1056 of file lpi_clp.cpp.

## ◆ SCIPlpiChgObjsen()

 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 1079 of file lpi_clp.cpp.

Referenced by SCIPlpiChgCoef(), SCIPlpiCreate(), and SCIPlpiLoadColLP().

## ◆ SCIPlpiChgObj()

 SCIP_RETCODE SCIPlpiChgObj ( SCIP_LPI * lpi, int ncols, const int * ind, const 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 1099 of file lpi_clp.cpp.

## ◆ SCIPlpiScaleRow()

 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 1126 of file lpi_clp.cpp.

Referenced by SCIPlpiChgObj().

## ◆ SCIPlpiScaleCol()

 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 1199 of file lpi_clp.cpp.

Referenced by SCIPlpiScaleRow().

## ◆ SCIPlpiGetNRows()

 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 1276 of file lpi_clp.cpp.

## ◆ SCIPlpiGetNCols()

 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 1294 of file lpi_clp.cpp.

## ◆ SCIPlpiGetObjsen()

 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 1514 of file lpi_clp.cpp.

## ◆ SCIPlpiGetNNonz()

 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 1312 of file lpi_clp.cpp.

Referenced by SCIPlpiGetCols(), SCIPlpiGetNCols(), SCIPlpiGetRows(), and SCIPlpiLoadColLP().

## ◆ SCIPlpiGetCols()

 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 1333 of file lpi_clp.cpp.

Referenced by SCIPlpiGetNNonz(), and SCIPlpiScaleCol().

## ◆ SCIPlpiGetRows()

 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 1400 of file lpi_clp.cpp.

Referenced by scaleFirstRow(), SCIPlpiGetCols(), and SCIPlpiScaleRow().

## ◆ SCIPlpiGetColNames()

 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 1464 of file lpi_clp.cpp.

Referenced by SCIPlpiGetRows().

## ◆ SCIPlpiGetRowNames()

 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 1480 of file lpi_clp.cpp.

Referenced by SCIPlpiGetColNames().

## ◆ SCIPlpiGetObj()

 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 1534 of file lpi_clp.cpp.

Referenced by lpFlushChgCols(), lpLexDualSimplex(), SCIPlpiGetObjsen(), SCIPlpiScaleCol(), and SCIPlpMarkFlushed().

## ◆ SCIPlpiGetBounds()

 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 1557 of file lpi_clp.cpp.

## ◆ SCIPlpiGetSides()

 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 1588 of file lpi_clp.cpp.

## ◆ SCIPlpiGetCoef()

 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 1619 of file lpi_clp.cpp.

Referenced by SCIPdummyDebugMethodForSun(), SCIPlpiGetSides(), and updateObjUpperbound().

## ◆ SCIPlpiSolvePrimal()

 SCIP_RETCODE SCIPlpiSolvePrimal ( SCIP_LPI * lpi )

calls primal simplex to solve the LP

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 1653 of file lpi_clp.cpp.

## ◆ SCIPlpiSolveDual()

 SCIP_RETCODE SCIPlpiSolveDual ( SCIP_LPI * lpi )

calls dual simplex to solve the LP

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 1726 of file lpi_clp.cpp.

## ◆ 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 1801 of file lpi_clp.cpp.

Referenced by lpBarrier(), SCIPlpiSolveDual(), and SolveWSimplex().

## ◆ SCIPlpiStartStrongbranch()

 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 1842 of file lpi_clp.cpp.

References NULL, SCIP_OKAY, SCIPlpiEndStrongbranch(), and SCIP_LPi::spx.

Referenced by SCIPconflictAnalyzeStrongbranch(), SCIPlpiSolveBarrier(), and SCIPlpStartStrongbranch().

## ◆ SCIPlpiEndStrongbranch()

 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 1851 of file lpi_clp.cpp.

References lpiStrongbranch(), NULL, SCIP_OKAY, and SCIP_LPi::spx.

## ◆ SCIPlpiStrongbranchFrac()

 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 2190 of file lpi_clp.cpp.

Referenced by lpiStrongbranch(), and SCIPcolGetStrongbranch().

## ◆ SCIPlpiStrongbranchesFrac()

 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 2211 of file lpi_clp.cpp.

Referenced by SCIPcolGetStrongbranches(), and SCIPlpiStrongbranchFrac().

## ◆ SCIPlpiStrongbranchInt()

 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 2236 of file lpi_clp.cpp.

Referenced by SCIPcolGetStrongbranch(), and SCIPlpiStrongbranchesFrac().

## ◆ SCIPlpiStrongbranchesInt()

 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 2257 of file lpi_clp.cpp.

Referenced by SCIPcolGetStrongbranches(), and SCIPlpiStrongbranchInt().

## ◆ SCIPlpiWasSolved()

 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 2292 of file lpi_clp.cpp.

## ◆ SCIPlpiGetSolFeasibility()

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

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

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 2302 of file lpi_clp.cpp.

Referenced by lpAlgorithm(), SCIPlpiStrongbranch(), and SCIPlpiWasSolved().

## ◆ SCIPlpiExistsPrimalRay()

 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 2347 of file lpi_clp.cpp.

## ◆ SCIPlpiHasPrimalRay()

 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 2365 of file lpi_clp.cpp.

## ◆ SCIPlpiIsPrimalUnbounded()

 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 2381 of file lpi_clp.cpp.

Referenced by addConcaveEstimatorMultivariate(), checkAltLPInfeasible(), and SCIPlpiHasPrimalRay().

## ◆ SCIPlpiIsPrimalInfeasible()

 SCIP_Bool SCIPlpiIsPrimalInfeasible ( SCIP_LPI * lpi )

returns TRUE iff LP is proven to be primal infeasible

Parameters
 lpi LP interface structure

Definition at line 2395 of file lpi_clp.cpp.

## ◆ SCIPlpiIsPrimalFeasible()

 SCIP_Bool SCIPlpiIsPrimalFeasible ( SCIP_LPI * lpi )

returns TRUE iff LP is proven to be primal feasible

Parameters
 lpi LP interface structure

Definition at line 2414 of file lpi_clp.cpp.

## ◆ SCIPlpiExistsDualRay()

 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 2430 of file lpi_clp.cpp.

## ◆ SCIPlpiHasDualRay()

 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 2448 of file lpi_clp.cpp.

Referenced by getFarkasProof(), lpSolve(), SCIPlpiExistsDualRay(), and SCIPlpSolveAndEval().

## ◆ SCIPlpiIsDualUnbounded()

 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 2476 of file lpi_clp.cpp.

Referenced by SCIPlpiHasDualRay().

## ◆ SCIPlpiIsDualInfeasible()

 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 2493 of file lpi_clp.cpp.

Referenced by SCIPlpiIsDualUnbounded().

## ◆ SCIPlpiIsDualFeasible()

 SCIP_Bool SCIPlpiIsDualFeasible ( SCIP_LPI * lpi )

returns TRUE iff LP is proven to be dual feasible

Parameters
 lpi LP interface structure

Definition at line 2507 of file lpi_clp.cpp.

## ◆ SCIPlpiIsOptimal()

 SCIP_Bool SCIPlpiIsOptimal ( SCIP_LPI * lpi )

returns TRUE iff LP was solved to optimality

Parameters
 lpi LP interface structure

Definition at line 2521 of file lpi_clp.cpp.

## ◆ SCIPlpiIsStable()

 SCIP_Bool SCIPlpiIsStable ( SCIP_LPI * lpi )

returns TRUE iff current LP basis is stable

Parameters
 lpi LP interface structure

Definition at line 2539 of file lpi_clp.cpp.

Referenced by checkAltLPInfeasible(), lpSolveStable(), SCIPlpiIsOptimal(), and SCIPlpiStrongbranch().

## ◆ SCIPlpiIsObjlimExc()

 SCIP_Bool SCIPlpiIsObjlimExc ( SCIP_LPI * lpi )

returns TRUE iff the objective limit was reached

Parameters
 lpi LP interface structure

Definition at line 2577 of file lpi_clp.cpp.

## ◆ SCIPlpiIsIterlimExc()

 SCIP_Bool SCIPlpiIsIterlimExc ( SCIP_LPI * lpi )

returns TRUE iff the iteration limit was reached

Parameters
 lpi LP interface structure

Definition at line 2607 of file lpi_clp.cpp.

## ◆ SCIPlpiIsTimelimExc()

 SCIP_Bool SCIPlpiIsTimelimExc ( SCIP_LPI * lpi )

returns TRUE iff the time limit was reached

Parameters
 lpi LP interface structure

Definition at line 2623 of file lpi_clp.cpp.

Referenced by lpSolve(), SCIPlpComputeRelIntPoint(), and SCIPlpiIsIterlimExc().

## ◆ SCIPlpiGetInternalStatus()

 int SCIPlpiGetInternalStatus ( SCIP_LPI * lpi )

returns the internal solution status of the solver

Parameters
 lpi LP interface structure

Definition at line 2639 of file lpi_clp.cpp.

Referenced by checkAltLPInfeasible(), lpSolve(), and SCIPlpiIsTimelimExc().

## ◆ SCIPlpiIgnoreInstability()

 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 1496 of file lpi_clp.cpp.

Referenced by lpSolveStable(), and SCIPlpiGetInternalStatus().

## ◆ SCIPlpiGetObjval()

 SCIP_RETCODE SCIPlpiGetObjval ( SCIP_LPI * lpi, SCIP_Real * objval )

gets objective value of solution

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 2653 of file lpi_clp.cpp.

## ◆ SCIPlpiGetSol()

 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 2671 of file lpi_clp.cpp.

## ◆ SCIPlpiGetPrimalRay()

 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 2715 of file lpi_clp.cpp.

Referenced by SCIPlpGetPrimalRay(), SCIPlpGetUnboundedSol(), and SCIPlpiGetSol().

## ◆ SCIPlpiGetDualfarkas()

 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.

Note
The Farkas proof might be numerically questionable which is indicated by "hasRay" use SCIPlpiHasDualRay() to check that!
Parameters
 lpi LP interface structure dualfarkas dual Farkas row multipliers

Definition at line 2740 of file lpi_clp.cpp.

Referenced by getFarkasProof(), SCIPlpGetDualfarkas(), and SCIPlpiGetPrimalRay().

## ◆ SCIPlpiGetIterations()

 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 2772 of file lpi_clp.cpp.

## ◆ SCIPlpiGetRealSolQuality()

 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 2790 of file lpi_clp.cpp.

## ◆ SCIPlpiGetBase()

 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 (the status is need for the row and not for the slack column)

Definition at line 2817 of file lpi_clp.cpp.

## ◆ SCIPlpiSetBase()

 SCIP_RETCODE SCIPlpiSetBase ( SCIP_LPI * lpi, const int * cstat, const 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 2905 of file lpi_clp.cpp.

## ◆ SCIPlpiGetBasisInd()

 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 3021 of file lpi_clp.cpp.

Referenced by lpiGetBInvVec(), SCIPlpGetBasisInd(), SCIPlpiGetBInvRow(), and SCIPlpiSetBase().

## ◆ 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 3073 of file lpi_clp.cpp.

Referenced by SCIPlpGetBInvRow(), SCIPlpiGetBasisInd(), and SCIPlpiGetBInvARow().

## ◆ SCIPlpiGetBInvCol()

 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 3108 of file lpi_clp.cpp.

Referenced by lpiGetBInvVec(), SCIPlpGetBInvCol(), and SCIPlpiGetBInvRow().

## ◆ SCIPlpiGetBInvARow()

 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 3146 of file lpi_clp.cpp.

Referenced by SCIPlpGetBInvARow(), and SCIPlpiGetBInvCol().

## ◆ SCIPlpiGetBInvACol()

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

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

get dense column 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 column 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 c column number 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 3181 of file lpi_clp.cpp.

Referenced by SCIPlpGetBInvACol(), and SCIPlpiGetBInvARow().

## ◆ SCIPlpiGetState()

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

stores LPi state (like basis information) into lpistate object

stores LP state (like basis information) into lpistate object

Parameters
 lpi LP interface structure blkmem block memory lpistate pointer to LPi state information (like basis information)

Definition at line 3221 of file lpi_clp.cpp.

Referenced by SCIPlpGetState(), SCIPlpiGetBInvACol(), and SCIPlpStartDive().

## ◆ SCIPlpiSetState()

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

loads LPi state (like basis information) into solver; note that the LP might have been extended with additional columns and rows since the state was stored with SCIPlpiGetState()

Parameters
 lpi LP interface structure blkmem block memory lpistate LPi state information (like basis information)

Definition at line 3261 of file lpi_clp.cpp.

Referenced by SCIPlpiGetState(), and SCIPlpSetState().

## ◆ SCIPlpiClearState()

 SCIP_RETCODE SCIPlpiClearState ( SCIP_LPI * lpi )

clears current LPi state (like basis information) of the solver

Parameters
 lpi LP interface structure

Definition at line 3315 of file lpi_clp.cpp.

Referenced by SCIPlpiSetState(), and SCIPtreeEndProbing().

## ◆ SCIPlpiFreeState()

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

frees LPi state information

frees LP state information

Parameters
 lpi LP interface structure blkmem block memory lpistate pointer to LPi state information (like basis information)

Definition at line 3331 of file lpi_clp.cpp.

Referenced by SCIPlpFreeState(), and SCIPlpiClearState().

## ◆ SCIPlpiHasStateBasis()

 SCIP_Bool SCIPlpiHasStateBasis ( SCIP_LPI * lpi, SCIP_LPISTATE * lpistate )

checks, whether the given LPi state contains simplex basis information

checks, whether the given LP state contains simplex basis information

Parameters
 lpi LP interface structure lpistate LP state information (like basis information)

Definition at line 3349 of file lpi_clp.cpp.

Referenced by SCIPlpiFreeState(), and SCIPlpSetState().

 SCIP_RETCODE SCIPlpiReadState ( SCIP_LPI * lpi, const char * fname )

reads LPi state (like basis information from a file

reads LP state (like basis information) from a file

reads LP state (like basis information from a file

Read a basis from the given filename, returns -1 on file error, 0 if no values, 1 if values

Parameters
 lpi LP interface structure fname file name

Definition at line 3358 of file lpi_clp.cpp.

Referenced by SCIPlpiHasStateBasis().

## ◆ SCIPlpiWriteState()

 SCIP_RETCODE SCIPlpiWriteState ( SCIP_LPI * lpi, const char * fname )

writes LPi state (like basis information) to a file

writes LP state (like basis information) to a file

Write the basis in MPS format to the specified file. If writeValues true, writes values of structurals (and adds VALUES to end of NAME card)

parameters:

• filename
• bool writeValues
• int formatType (0 - normal, 1 - extra accuracy, 2 - IEEE hex)
Parameters
 lpi LP interface structure fname file name

Definition at line 3375 of file lpi_clp.cpp.

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

## ◆ SCIPlpiGetNorms()

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

stores LPi pricing norms into lpinorms object

stores LPi pricing norms information

stores LPi pricing norms information

stores LPi pricing norms information

stores LPi pricing norms information

stores LPi pricing norms information

stores LPi pricing norms information

stores LPi pricing norms information

stores LPi pricing norms information

stores LPi pricing norms information

Parameters
 lpi LP interface structure blkmem block memory lpinorms pointer to LPi pricing norms information

Definition at line 3412 of file lpi_clp.cpp.

Referenced by SCIPlpGetNorms(), and SCIPlpiWriteState().

## ◆ SCIPlpiSetNorms()

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

loads LPi pricing norms into solver; note that the LP might have been extended with additional columns and rows since the norms were stored with SCIPlpiGetNorms()

loads LPi pricing norms into solver; note that the LP might have been extended with additional columns and rows since the state was stored with SCIPlpiGetNorms()

Parameters
 lpi LP interface structure blkmem block memory lpinorms LPi pricing norms information

Definition at line 3428 of file lpi_clp.cpp.

Referenced by SCIPlpiGetNorms(), and SCIPlpSetNorms().

## ◆ SCIPlpiFreeNorms()

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

frees LPi pricing norms information

frees pricing norms information

Parameters
 lpi LP interface structure blkmem block memory lpinorms pointer to LPi pricing norms information

Definition at line 3441 of file lpi_clp.cpp.

Referenced by SCIPlpFreeNorms(), and SCIPlpiSetNorms().

## ◆ SCIPlpiGetIntpar()

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

gets integer parameter of LP

gets integer parameter of LP

CPLEX supported FASTMIP in versions up to 12.6.1. FASTMIP fastens the lp solving process but therefor it might happen that there will be a loss in precision (because e.g. the optimal basis will not be factorized again).

Parameters
 lpi LP interface structure type parameter number ival buffer to store the parameter value

Definition at line 3466 of file lpi_clp.cpp.

Referenced by lpCheckIntpar(), SCIPlpiFreeNorms(), and SCIPlpStartDive().

## ◆ SCIPlpiSetIntpar()

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

sets integer parameter of LP

Amount of print out: 0 - none 1 - just final 2 - just factorizations 3 - as 2 plus a bit more 4 - verbose above that 8,16,32 etc just for selective SCIPdebug

Parameters
 lpi LP interface structure type parameter number ival parameter value

Definition at line 3510 of file lpi_clp.cpp.

## ◆ SCIPlpiGetRealpar()

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

gets floating point parameter of LP

Parameters
 lpi LP interface structure type parameter number dval buffer to store the parameter value

Definition at line 3612 of file lpi_clp.cpp.

Referenced by conflictAnalyzeLP(), lpCheckRealpar(), and SCIPlpiSetIntpar().

## ◆ SCIPlpiSetRealpar()

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

sets floating point parameter of LP

Parameters
 lpi LP interface structure type parameter number dval parameter value

Definition at line 3658 of file lpi_clp.cpp.

## ◆ SCIPlpiInfinity()

 SCIP_Real SCIPlpiInfinity ( SCIP_LPI * lpi )

returns value treated as infinity in the LP solver

Parameters
 lpi LP interface structure

Definition at line 3715 of file lpi_clp.cpp.

## ◆ SCIPlpiIsInfinity()

 SCIP_Bool SCIPlpiIsInfinity ( SCIP_LPI * lpi, SCIP_Real val )

checks if given value is treated as infinity in the LP solver

Parameters
 lpi LP interface structure val value to be checked for infinity

Definition at line 3726 of file lpi_clp.cpp.

 SCIP_RETCODE SCIPlpiReadLP ( SCIP_LPI * lpi, const char * fname )

read file in MPS format parameters: filename bool keepNames bool ignoreErrors

Parameters
 lpi LP interface structure fname file name

Definition at line 3766 of file lpi_clp.cpp.

Referenced by fileExists().

## ◆ SCIPlpiWriteLP()

 SCIP_RETCODE SCIPlpiWriteLP ( SCIP_LPI * lpi, const char * fname )

writes LP to a file

write file in MPS format parameters: filename int formatType (0 - normal, 1 - extra accuracy, 2 - IEEE hex) int numberAcross (1 or 2 values should be specified on every data line in the MPS file) double objSense

Parameters
 lpi LP interface structure fname file name

Definition at line 3794 of file lpi_clp.cpp.