#include <ClpPrimalColumnPivot.hpp>
Inheritance diagram for ClpPrimalColumnPivot:
Public Member Functions | |
Algorithmic methods | |
| virtual int | pivotColumn (CoinIndexedVector *updates, CoinIndexedVector *spareRow1, CoinIndexedVector *spareRow2, CoinIndexedVector *spareColumn1, CoinIndexedVector *spareColumn2)=0 |
| virtual void | updateWeights (CoinIndexedVector *input) |
| Updates weights - part 1 (may be empty). | |
| virtual void | saveWeights (ClpSimplex *model, int mode)=0 |
| virtual int | pivotRow (double &way) |
| virtual void | clearArrays () |
| Gets rid of all arrays (may be empty). | |
| virtual bool | looksOptimal () const |
| Returns true if would not find any column. | |
Constructors and destructors | |
| ClpPrimalColumnPivot () | |
| Default Constructor. | |
| ClpPrimalColumnPivot (const ClpPrimalColumnPivot &) | |
| Copy constructor. | |
| ClpPrimalColumnPivot & | operator= (const ClpPrimalColumnPivot &rhs) |
| Assignment operator. | |
| virtual | ~ClpPrimalColumnPivot () |
| Destructor. | |
| virtual ClpPrimalColumnPivot * | clone (bool copyData=true) const=0 |
| Clone. | |
Other | |
| ClpSimplex * | model () |
| Returns model. | |
| int | type () |
| Returns type (above 63 is extra information). | |
| virtual int | numberSprintColumns (int &numberIterations) const |
| virtual void | switchOffSprint () |
| Switch off sprint idea. | |
Protected Attributes | |
Protected member data | |
| ClpSimplex * | model_ |
| Pointer to model. | |
| int | type_ |
| Type of column pivot algorithm. | |
Abstract Base Class for describing an interface to an algorithm to choose column pivot in primal simplex algorithm. For some algorithms e.g. Dantzig choice then some functions may be null. For Dantzig the only one of any importance is pivotColumn.
If you wish to inherit from this look at ClpPrimalColumnDantzig.cpp as that is simplest version.
Definition at line 22 of file ClpPrimalColumnPivot.hpp.
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Returns number of extra columns for sprint algorithm - 0 means off. Also number of iterations before recompute Definition at line 74 of file ClpPrimalColumnPivot.cpp. Referenced by ClpSimplexPrimal::primal().
00075 {
00076 return 0;
00077 }
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Returns pivot column, -1 if none Normally updates reduced costs using result of last iteration before selecting incoming column. The Packed CoinIndexedVector updates has cost updates - for normal LP that is just +-weight where a feasibility changed. It also has reduced cost from last iteration in pivot row Inside pivotColumn the pivotRow_ and reduced cost from last iteration are also used. So in the simplest case i.e. feasible we compute the row of the tableau corresponding to last pivot and add a multiple of this to current reduced costs. We can use other arrays to help updates Implemented in ClpPrimalColumnDantzig, and ClpPrimalQuadraticDantzig. Referenced by ClpSimplexPrimal::primalColumn(), and ClpSimplexPrimalQuadratic::primalQuadratic2(). |
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Signals pivot row choice: -2 (default) - use normal pivot row choice -1 to numberRows-1 - use this (will be checked) way should be -1 to go to lower bound, +1 to upper bound Definition at line 73 of file ClpPrimalColumnPivot.hpp.
00074 {way=0;return -2;};
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Saves any weights round factorization as pivot rows may change Will be empty unless steepest edge (will save model) May also recompute infeasibility stuff 1) before factorization 2) after good factorization (if weights empty may initialize) 3) after something happened but no factorization (e.g. check for infeasible) 4) as 2 but restore weights from previous snapshot 5) forces some initialization e.g. weights Also sets model Implemented in ClpPrimalColumnDantzig, and ClpPrimalQuadraticDantzig. Definition at line 54 of file ClpPrimalColumnPivot.cpp. References model_. Referenced by ClpSimplex::ClpSimplex(), ClpSimplex::originalModel(), ClpSimplexPrimalQuadratic::statusOfProblemInPrimal(), ClpSimplexPrimal::statusOfProblemInPrimal(), and ClpSimplexPrimal::whileIterating().
00055 {
00056 model_=model;
00057 }
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1.3.5