Clp trunk
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This is for Simplex stuff which is neither dual nor primal. More...
#include <ClpSimplexOther.hpp>
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 | parametrics (const char *dataFile) |
Version of parametrics which reads from file See CbcClpParam.cpp for details of format Returns -2 if unable to open file. | |
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. | |
ClpSimplex * | gubVersion (int *whichRows, int *whichColumns, int neededGub, int factorizationFrequency=50) |
Returns gub version of model or NULL whichRows has to be numberRows whichColumns has to be numberRows+numberColumns. | |
void | setGubBasis (ClpSimplex &original, const int *whichRows, const int *whichColumns) |
Sets basis from original. | |
void | getGubBasis (ClpSimplex &original, const int *whichRows, const int *whichColumns) const |
Restores basis to original. | |
void | cleanupAfterPostsolve () |
Quick try at cleaning up duals if postsolve gets wrong. | |
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. |
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 23 of file ClpSimplexOther.hpp.
void ClpSimplexOther::dualRanging | ( | int | numberCheck, |
const int * | which, | ||
double * | costIncrease, | ||
int * | sequenceIncrease, | ||
double * | costDecrease, | ||
int * | sequenceDecrease, | ||
double * | valueIncrease = NULL , |
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double * | valueDecrease = NULL |
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) |
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::parametrics | ( | const char * | dataFile | ) |
Version of parametrics which reads from file See CbcClpParam.cpp for details of format Returns -2 if unable to open file.
int ClpSimplexOther::writeBasis | ( | const char * | filename, |
bool | writeValues = false , |
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int | formatType = 0 |
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) | 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
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 |
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) | 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 , |
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bool | tightenBounds = false |
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) |
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.
ClpSimplex* ClpSimplexOther::gubVersion | ( | int * | whichRows, |
int * | whichColumns, | ||
int | neededGub, | ||
int | factorizationFrequency = 50 |
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) |
Returns gub version of model or NULL whichRows has to be numberRows whichColumns has to be numberRows+numberColumns.
void ClpSimplexOther::setGubBasis | ( | ClpSimplex & | original, |
const int * | whichRows, | ||
const int * | whichColumns | ||
) |
Sets basis from original.
void ClpSimplexOther::getGubBasis | ( | ClpSimplex & | original, |
const int * | whichRows, | ||
const int * | whichColumns | ||
) | const |
Restores basis to original.
void ClpSimplexOther::cleanupAfterPostsolve | ( | ) |
Quick try at cleaning up duals if postsolve gets wrong.
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 |
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) | 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;