Public Types
ClpDualRowSteepest Class Reference

Dual Row Pivot Steepest Edge Algorithm Class. More...

#include <ClpDualRowSteepest.hpp>

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List of all members.

Public Types

enum  Persistence { normal = 0x00, keep = 0x01 }
 enums for persistence More...

Public Member Functions

Algorithmic methods
virtual int pivotRow ()
 Returns pivot row, -1 if none.
virtual double updateWeights (CoinIndexedVector *input, CoinIndexedVector *spare, CoinIndexedVector *spare2, CoinIndexedVector *updatedColumn)
 Updates weights and returns pivot alpha.
virtual void updatePrimalSolution (CoinIndexedVector *input, double theta, double &changeInObjective)
 Updates primal solution (and maybe list of candidates) Uses input vector which it deletes Computes change in objective function.
virtual void saveWeights (ClpSimplex *model, int mode)
 Saves any weights round factorization as pivot rows may change 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.
virtual void unrollWeights ()
 Gets rid of last update.
virtual void clearArrays ()
 Gets rid of all arrays.
virtual bool looksOptimal () const
 Returns true if would not find any row.
virtual void maximumPivotsChanged ()
 Called when maximum pivots changes.
Constructors and destructors
 ClpDualRowSteepest (int mode=3)
 Default Constructor 0 is uninitialized, 1 full, 2 is partial uninitialized, 3 starts as 2 but may switch to 1.
 ClpDualRowSteepest (const ClpDualRowSteepest &)
 Copy constructor.
ClpDualRowSteepestoperator= (const ClpDualRowSteepest &rhs)
 Assignment operator.
void fill (const ClpDualRowSteepest &rhs)
 Fill most values.
virtual ~ClpDualRowSteepest ()
 Destructor.
virtual ClpDualRowPivotclone (bool copyData=true) const
 Clone.
gets and sets
int mode () const
 Mode.
void setPersistence (Persistence life)
 Set/ get persistence.
Persistence persistence () const
 Mode.

Private Attributes

Private member data
int state_
 Status 0) Normal.
int mode_
 If 0 then we are using uninitialized weights, 1 then full, if 2 then uninitialized partial, 3 switchable.
Persistence persistence_
 Life of weights.
double * weights_
 weight array
CoinIndexedVector * infeasible_
 square of infeasibility array (just for infeasible rows)
CoinIndexedVector * alternateWeights_
 alternate weight array (so we can unroll)
CoinIndexedVector * savedWeights_
 save weight array (so we can use checkpoint)
int * dubiousWeights_
 Dubious weights.

Detailed Description

Dual Row Pivot Steepest Edge Algorithm Class.

See Forrest-Goldfarb paper for algorithm

Definition at line 19 of file ClpDualRowSteepest.hpp.


Member Enumeration Documentation

enums for persistence

Enumerator:
normal 
keep 

Definition at line 67 of file ClpDualRowSteepest.hpp.


Constructor & Destructor Documentation

Default Constructor 0 is uninitialized, 1 full, 2 is partial uninitialized, 3 starts as 2 but may switch to 1.

By partial is meant that the weights are updated as normal but only part of the infeasible basic variables are scanned. This can be faster on very easy problems.

Copy constructor.

Destructor.


Member Function Documentation

virtual int ClpDualRowSteepest::pivotRow ( ) [virtual]

Returns pivot row, -1 if none.

Implements ClpDualRowPivot.

virtual double ClpDualRowSteepest::updateWeights ( CoinIndexedVector *  input,
CoinIndexedVector *  spare,
CoinIndexedVector *  spare2,
CoinIndexedVector *  updatedColumn 
) [virtual]

Updates weights and returns pivot alpha.

Also does FT update

Implements ClpDualRowPivot.

virtual void ClpDualRowSteepest::updatePrimalSolution ( CoinIndexedVector *  input,
double  theta,
double &  changeInObjective 
) [virtual]

Updates primal solution (and maybe list of candidates) Uses input vector which it deletes Computes change in objective function.

Implements ClpDualRowPivot.

virtual void ClpDualRowSteepest::saveWeights ( ClpSimplex model,
int  mode 
) [virtual]

Saves any weights round factorization as pivot rows may change 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) for strong branching - initialize (uninitialized) , infeasibilities

Reimplemented from ClpDualRowPivot.

virtual void ClpDualRowSteepest::unrollWeights ( ) [virtual]

Gets rid of last update.

Reimplemented from ClpDualRowPivot.

virtual void ClpDualRowSteepest::clearArrays ( ) [virtual]

Gets rid of all arrays.

Reimplemented from ClpDualRowPivot.

virtual bool ClpDualRowSteepest::looksOptimal ( ) const [virtual]

Returns true if would not find any row.

Reimplemented from ClpDualRowPivot.

virtual void ClpDualRowSteepest::maximumPivotsChanged ( ) [virtual]

Called when maximum pivots changes.

Reimplemented from ClpDualRowPivot.

ClpDualRowSteepest& ClpDualRowSteepest::operator= ( const ClpDualRowSteepest rhs)

Assignment operator.

Fill most values.

virtual ClpDualRowPivot* ClpDualRowSteepest::clone ( bool  copyData = true) const [virtual]

Clone.

Implements ClpDualRowPivot.

int ClpDualRowSteepest::mode ( ) const [inline]

Mode.

Definition at line 102 of file ClpDualRowSteepest.hpp.

Set/ get persistence.

Definition at line 106 of file ClpDualRowSteepest.hpp.

Mode.

Definition at line 109 of file ClpDualRowSteepest.hpp.


Member Data Documentation

Status 0) Normal.

-1) Needs initialization 1) Weights are stored by sequence number

Definition at line 123 of file ClpDualRowSteepest.hpp.

If 0 then we are using uninitialized weights, 1 then full, if 2 then uninitialized partial, 3 switchable.

Definition at line 126 of file ClpDualRowSteepest.hpp.

Life of weights.

Definition at line 128 of file ClpDualRowSteepest.hpp.

double* ClpDualRowSteepest::weights_ [private]

weight array

Definition at line 130 of file ClpDualRowSteepest.hpp.

CoinIndexedVector* ClpDualRowSteepest::infeasible_ [private]

square of infeasibility array (just for infeasible rows)

Definition at line 132 of file ClpDualRowSteepest.hpp.

CoinIndexedVector* ClpDualRowSteepest::alternateWeights_ [private]

alternate weight array (so we can unroll)

Definition at line 134 of file ClpDualRowSteepest.hpp.

CoinIndexedVector* ClpDualRowSteepest::savedWeights_ [private]

save weight array (so we can use checkpoint)

Definition at line 136 of file ClpDualRowSteepest.hpp.

Dubious weights.

Definition at line 138 of file ClpDualRowSteepest.hpp.


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