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# ClpSimplexOther Class Reference

This is for Simplex stuff which is neither dual nor primal. More...

`#include <ClpSimplexOther.hpp>`

Inheritance diagram for ClpSimplexOther:

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Collaboration diagram for ClpSimplexOther:

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List of all members.

## Methods
void | dualRanging (int numberCheck, const int *which, double *costIncrease, int *sequenceIncrease, double *costDecrease, int *sequenceDecrease, double *valueIncrease=NULL, double *valueDecrease=NULL)
| Dual ranging.
void | primalRanging (int numberCheck, const int *which, double *valueIncrease, int *sequenceIncrease, double *valueDecrease, int *sequenceDecrease)
| Primal ranging.
int | parametrics (double startingTheta, double &endingTheta, double reportIncrement, const double *changeLowerBound, const double *changeUpperBound, const double *changeLowerRhs, const double *changeUpperRhs, const double *changeObjective)
| Parametrics This is an initial slow version.
int | writeBasis (const char *filename, bool writeValues=false, int formatType=0) const
| Write the basis in MPS format to the specified file.
int | readBasis (const char *filename)
| Read a basis from the given filename.
ClpSimplex * | dualOfModel (double fractionRowRanges=1.0, double fractionColumnRanges=1.0) const
| Creates dual of a problem if looks plausible (defaults will always create model) fractionRowRanges is fraction of rows allowed to have ranges fractionColumnRanges is fraction of columns allowed to have ranges.
int | restoreFromDual (const ClpSimplex *dualProblem)
| Restores solution from dualized problem non-zero return code indicates minor problems.
ClpSimplex * | crunch (double *rhs, int *whichRows, int *whichColumns, int &nBound, bool moreBounds=false, bool tightenBounds=false)
| Does very cursory presolve.
void | afterCrunch (const ClpSimplex &small, const int *whichRows, const int *whichColumns, int nBound)
| After very cursory presolve.
int | tightenIntegerBounds (double *rhsSpace)
| Tightens integer bounds - returns number tightened or -1 if infeasible.
int | expandKnapsack (int knapsackRow, int &numberOutput, double *buildObj, CoinBigIndex *buildStart, int *buildRow, double *buildElement, int reConstruct=-1) const
| Expands out all possible combinations for a knapsack If buildObj NULL then just computes space needed - returns number elements On entry numberOutput is maximum allowed, on exit it is number needed or -1 (as will be number elements) if maximum exceeded.
int | parametricsLoop (double startingTheta, double &endingTheta, double reportIncrement, const double *changeLower, const double *changeUpper, const double *changeObjective, ClpDataSave &data, bool canTryQuick)
| Parametrics - inner loop This first attempt is when reportIncrement non zero and may not report endingTheta correctly If it can not reach input endingTheta return code will be 1 for infeasible, 2 for unbounded, otherwise 0.
void | statusOfProblemInParametrics (int type, ClpDataSave &saveData)
| Refactorizes if necessary Checks if finished.
int | whileIterating (double startingTheta, double &endingTheta, double reportIncrement, const double *changeLower, const double *changeUpper, const double *changeObjective)
| This has the flow between re-factorizations.
int | nextTheta (int type, double maxTheta, double *primalChange, double *dualChange, const double *changeLower, const double *changeUpper, const double *changeObjective)
| Computes next theta and says if objective or bounds (0= bounds, 1 objective, -1 none).
void | checkDualRatios (CoinIndexedVector *rowArray, CoinIndexedVector *columnArray, double &costIncrease, int &sequenceIncrease, double &alphaIncrease, double &costDecrease, int &sequenceDecrease, double &alphaDecrease)
| Row array has row part of pivot row Column array has column part.
void | checkPrimalRatios (CoinIndexedVector *rowArray, int direction)
| Row array has pivot column This is used in primal ranging.
double | primalRanging1 (int whichIn, int whichOther)
| Returns new value of whichOther when whichIn enters basis.

## Detailed Description

This is for Simplex stuff which is neither dual nor primal.

It inherits from ClpSimplex. It has no data of its own and is never created - only cast from a ClpSimplex object at algorithm time.

Definition at line 22 of file ClpSimplexOther.hpp.

## Member Function Documentation

void ClpSimplexOther::dualRanging | ( | int | numberCheck,
|  | const int * | which,
|  | double * | costIncrease,
|  | int * | sequenceIncrease,
|  | double * | costDecrease,
|  | int * | sequenceDecrease,
|  | double * | valueIncrease = `NULL`,
|  | double * | valueDecrease = `NULL` |
| ) |  |  |

Dual ranging.

This computes increase/decrease in cost for each given variable and corresponding sequence numbers which would change basis. Sequence numbers are 0..numberColumns and numberColumns.. for artificials/slacks. For non-basic variables the information is trivial to compute and the change in cost is just minus the reduced cost and the sequence number will be that of the non-basic variables. For basic variables a ratio test is between the reduced costs for non-basic variables and the row of the tableau corresponding to the basic variable. The increase/decrease value is always >= 0.0

Up to user to provide correct length arrays where each array is of length numberCheck. which contains list of variables for which information is desired. All other arrays will be filled in by function. If fifth entry in which is variable 7 then fifth entry in output arrays will be information for variable 7.

If valueIncrease/Decrease not NULL (both must be NULL or both non NULL) then these are filled with the value of variable if such a change in cost were made (the existing bounds are ignored)

When here - guaranteed optimal

Reimplemented from ClpSimplex.

void ClpSimplexOther::primalRanging | ( | int | numberCheck,
|  | const int * | which,
|  | double * | valueIncrease,
|  | int * | sequenceIncrease,
|  | double * | valueDecrease,
|  | int * | sequenceDecrease |
| ) |  |  |

Primal ranging.

This computes increase/decrease in value for each given variable and corresponding sequence numbers which would change basis. Sequence numbers are 0..numberColumns and numberColumns.. for artificials/slacks. This should only be used for non-basic variabls as otherwise information is pretty useless For basic variables the sequence number will be that of the basic variables.

Up to user to provide correct length arrays where each array is of length numberCheck. which contains list of variables for which information is desired. All other arrays will be filled in by function. If fifth entry in which is variable 7 then fifth entry in output arrays will be information for variable 7.

When here - guaranteed optimal

Reimplemented from ClpSimplex.

int ClpSimplexOther::parametrics | ( | double | startingTheta,
|  | double & | endingTheta,
|  | double | reportIncrement,
|  | const double * | changeLowerBound,
|  | const double * | changeUpperBound,
|  | const double * | changeLowerRhs,
|  | const double * | changeUpperRhs,
|  | const double * | changeObjective |
| ) |  |  |

Parametrics This is an initial slow version.

The code uses current bounds + theta * change (if change array not NULL) and similarly for objective. It starts at startingTheta and returns ending theta in endingTheta. If reportIncrement 0.0 it will report on any movement If reportIncrement >0.0 it will report at startingTheta+k*reportIncrement. If it can not reach input endingTheta return code will be 1 for infeasible, 2 for unbounded, if error on ranges -1, otherwise 0. Normal report is just theta and objective but if event handler exists it may do more On exit endingTheta is maximum reached (can be used for next startingTheta)

int ClpSimplexOther::parametricsLoop | ( | double | startingTheta,
|  | double & | endingTheta,
|  | double | reportIncrement,
|  | const double * | changeLower,
|  | const double * | changeUpper,
|  | const double * | changeObjective,
|  | ClpDataSave & | data,
|  | bool | canTryQuick |
| ) |  |  | `[private]`

Parametrics - inner loop This first attempt is when reportIncrement non zero and may not report endingTheta correctly If it can not reach input endingTheta return code will be 1 for infeasible, 2 for unbounded, otherwise 0.

Normal report is just theta and objective but if event handler exists it may do more

void ClpSimplexOther::statusOfProblemInParametrics | ( | int | type,
|  | ClpDataSave & | saveData |
| ) |  |  | `[private]`

Refactorizes if necessary Checks if finished.

Updates status.

type - 0 initial so set up save arrays etc

- 1 normal -if good update save
- 2 restoring from saved

int ClpSimplexOther::whileIterating | ( | double | startingTheta,
|  | double & | endingTheta,
|  | double | reportIncrement,
|  | const double * | changeLower,
|  | const double * | changeUpper,
|  | const double * | changeObjective |
| ) |  |  | `[private]`

This has the flow between re-factorizations.

Reasons to come out: -1 iterations etc -2 inaccuracy -3 slight inaccuracy (and done iterations) +0 looks optimal (might be unbounded - but we will investigate) +1 looks infeasible +3 max iterations

int ClpSimplexOther::nextTheta | ( | int | type,
|  | double | maxTheta,
|  | double * | primalChange,
|  | double * | dualChange,
|  | const double * | changeLower,
|  | const double * | changeUpper,
|  | const double * | changeObjective |
| ) |  |  | `[private]`

Computes next theta and says if objective or bounds (0= bounds, 1 objective, -1 none).

theta is in theta_. type 1 bounds, 2 objective, 3 both.

void ClpSimplexOther::checkDualRatios | ( | CoinIndexedVector * | rowArray,
|  | CoinIndexedVector * | columnArray,
|  | double & | costIncrease,
|  | int & | sequenceIncrease,
|  | double & | alphaIncrease,
|  | double & | costDecrease,
|  | int & | sequenceDecrease,
|  | double & | alphaDecrease |
| ) |  |  | `[private]`

Row array has row part of pivot row Column array has column part.

This is used in dual ranging

void ClpSimplexOther::checkPrimalRatios | ( | CoinIndexedVector * | rowArray,
|  | int | direction |
| ) |  |  | `[private]`

Row array has pivot column This is used in primal ranging.

double ClpSimplexOther::primalRanging1 | ( | int | whichIn,
|  | int | whichOther |
| ) |  |  | `[private]`

Returns new value of whichOther when whichIn enters basis.

int ClpSimplexOther::writeBasis | ( | const char * | filename,
|  | bool | writeValues = `false`,
|  | int | formatType = `0` |
| ) |  |  | const

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)

Row and column names may be null. formatType is

- 0 - normal
- 1 - extra accuracy
- 2 - IEEE hex (later)

Returns non-zero on I/O error

Reimplemented from ClpSimplex.

int ClpSimplexOther::readBasis | ( | const char * | filename | ) |

Read a basis from the given filename.

Reimplemented from ClpSimplex.

ClpSimplex* ClpSimplexOther::dualOfModel | ( | double | fractionRowRanges = `1.0`,
|  | double | fractionColumnRanges = `1.0` |
| ) |  |  | const

Creates dual of a problem if looks plausible (defaults will always create model) fractionRowRanges is fraction of rows allowed to have ranges fractionColumnRanges is fraction of columns allowed to have ranges.

int ClpSimplexOther::restoreFromDual | ( | const ClpSimplex * | dualProblem | ) |

Restores solution from dualized problem non-zero return code indicates minor problems.

ClpSimplex* ClpSimplexOther::crunch | ( | double * | rhs,
|  | int * | whichRows,
|  | int * | whichColumns,
|  | int & | nBound,
|  | bool | moreBounds = `false`,
|  | bool | tightenBounds = `false` |
| ) |  |  |

Does very cursory presolve.

rhs is numberRows, whichRows is 3*numberRows and whichColumns is 2*numberColumns.

void ClpSimplexOther::afterCrunch | ( | const ClpSimplex & | small,
|  | const int * | whichRows,
|  | const int * | whichColumns,
|  | int | nBound |
| ) |  |  |

After very cursory presolve.

rhs is numberRows, whichRows is 3*numberRows and whichColumns is 2*numberColumns.

int ClpSimplexOther::tightenIntegerBounds | ( | double * | rhsSpace | ) |

Tightens integer bounds - returns number tightened or -1 if infeasible.

int ClpSimplexOther::expandKnapsack | ( | int | knapsackRow,
|  | int & | numberOutput,
|  | double * | buildObj,
|  | CoinBigIndex * | buildStart,
|  | int * | buildRow,
|  | double * | buildElement,
|  | int | reConstruct = `-1` |
| ) |  |  | const

Expands out all possible combinations for a knapsack If buildObj NULL then just computes space needed - returns number elements On entry numberOutput is maximum allowed, on exit it is number needed or -1 (as will be number elements) if maximum exceeded.

numberOutput will have at least space to return values which reconstruct input. Rows returned will be original rows but no entries will be returned for any rows all of whose entries are in knapsack. So up to user to allow for this. If reConstruct >=0 then returns number of entrie which make up item "reConstruct" in expanded knapsack. Values in buildRow and buildElement;

The documentation for this class was generated from the following file:

- /home/coin/SVN-release/Osi-0.98.1/Clp/src/ClpSimplexOther.hpp