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CoinPostsolveMatrix Class Reference

Augments CoinPrePostsolveMatrix with information about the problem that is only needed during postsolve. More...

#include <CoinPresolveMatrix.hpp>

+ Inheritance diagram for CoinPostsolveMatrix:
+ Collaboration diagram for CoinPostsolveMatrix:

Public Member Functions

 CoinPostsolveMatrix (int ncols_alloc, int nrows_alloc, CoinBigIndex nelems_alloc)
 `Native' constructor More...
 
 CoinPostsolveMatrix (ClpSimplex *si, int ncols0, int nrows0, CoinBigIndex nelems0, double maxmin_, double *sol, double *acts, unsigned char *colstat, unsigned char *rowstat)
 Clp OSI constructor. More...
 
 CoinPostsolveMatrix (OsiSolverInterface *si, int ncols0, int nrows0, CoinBigIndex nelems0, double maxmin_, double *sol, double *acts, unsigned char *colstat, unsigned char *rowstat)
 Generic OSI constructor. More...
 
void assignPresolveToPostsolve (CoinPresolveMatrix *&preObj)
 Load an empty CoinPostsolveMatrix from a CoinPresolveMatrix. More...
 
 ~CoinPostsolveMatrix ()
 Destructor. More...
 
void check_nbasic ()
 debug More...
 
- Public Member Functions inherited from CoinPrePostsolveMatrix
 CoinPrePostsolveMatrix (int ncols_alloc, int nrows_alloc, CoinBigIndex nelems_alloc)
 `Native' constructor More...
 
 CoinPrePostsolveMatrix (const OsiSolverInterface *si, int ncols_, int nrows_, CoinBigIndex nelems_)
 Generic OSI constructor. More...
 
 CoinPrePostsolveMatrix (const ClpSimplex *si, int ncols_, int nrows_, CoinBigIndex nelems_, double bulkRatio)
 ClpOsi constructor. More...
 
 ~CoinPrePostsolveMatrix ()
 Destructor. More...
 
void setRowStatus (int sequence, Status status)
 Set row status (i.e., status of artificial for this row) More...
 
Status getRowStatus (int sequence) const
 Get row status. More...
 
bool rowIsBasic (int sequence) const
 Check if artificial for this row is basic. More...
 
void setColumnStatus (int sequence, Status status)
 Set column status (i.e., status of primal variable) More...
 
Status getColumnStatus (int sequence) const
 Get column (structural variable) status. More...
 
bool columnIsBasic (int sequence) const
 Check if column (structural variable) is basic. More...
 
void setRowStatusUsingValue (int iRow)
 Set status of row (artificial variable) to the correct nonbasic status given bounds and current value. More...
 
void setColumnStatusUsingValue (int iColumn)
 Set status of column (structural variable) to the correct nonbasic status given bounds and current value. More...
 
void setStructuralStatus (const char *strucStatus, int lenParam)
 Set column (structural variable) status vector. More...
 
void setArtificialStatus (const char *artifStatus, int lenParam)
 Set row (artificial variable) status vector. More...
 
void setStatus (const CoinWarmStartBasis *basis)
 Set the status of all variables from a basis. More...
 
CoinWarmStartBasisgetStatus ()
 Get status in the form of a CoinWarmStartBasis. More...
 
const char * columnStatusString (int j) const
 Return a print string for status of a column (structural variable) More...
 
const char * rowStatusString (int i) const
 Return a print string for status of a row (artificial variable) More...
 
void setObjOffset (double offset)
 Set the objective function offset for the original system. More...
 
void setObjSense (double objSense)
 Set the objective sense (max/min) More...
 
void setPrimalTolerance (double primTol)
 Set the primal feasibility tolerance. More...
 
void setDualTolerance (double dualTol)
 Set the dual feasibility tolerance. More...
 
void setColLower (const double *colLower, int lenParam)
 Set column lower bounds. More...
 
void setColUpper (const double *colUpper, int lenParam)
 Set column upper bounds. More...
 
void setColSolution (const double *colSol, int lenParam)
 Set column solution. More...
 
void setCost (const double *cost, int lenParam)
 Set objective coefficients. More...
 
void setReducedCost (const double *redCost, int lenParam)
 Set reduced costs. More...
 
void setRowLower (const double *rowLower, int lenParam)
 Set row lower bounds. More...
 
void setRowUpper (const double *rowUpper, int lenParam)
 Set row upper bounds. More...
 
void setRowPrice (const double *rowSol, int lenParam)
 Set row solution. More...
 
void setRowActivity (const double *rowAct, int lenParam)
 Set row activity. More...
 
int getNumCols () const
 Get current number of columns. More...
 
int getNumRows () const
 Get current number of rows. More...
 
int getNumElems () const
 Get current number of non-zero coefficients. More...
 
const CoinBigIndexgetColStarts () const
 Get column start vector for column-major packed matrix. More...
 
const int * getColLengths () const
 Get column length vector for column-major packed matrix. More...
 
const int * getRowIndicesByCol () const
 Get vector of row indices for column-major packed matrix. More...
 
const double * getElementsByCol () const
 Get vector of elements for column-major packed matrix. More...
 
const double * getColLower () const
 Get column lower bounds. More...
 
const double * getColUpper () const
 Get column upper bounds. More...
 
const double * getCost () const
 Get objective coefficients. More...
 
const double * getRowLower () const
 Get row lower bounds. More...
 
const double * getRowUpper () const
 Get row upper bounds. More...
 
const double * getColSolution () const
 Get column solution (primal variable values) More...
 
const double * getRowActivity () const
 Get row activity (constraint lhs values) More...
 
const double * getRowPrice () const
 Get row solution (dual variables) More...
 
const double * getReducedCost () const
 Get reduced costs. More...
 
int countEmptyCols ()
 Count empty columns. More...
 
CoinMessageHandlermessageHandler () const
 Return message handler. More...
 
void setMessageHandler (CoinMessageHandler *handler)
 Set message handler. More...
 
CoinMessages messages () const
 Return messages. More...
 

Public Attributes

Column thread structures

As mentioned in the class documentation, the entries for a given column do not necessarily occupy a contiguous block of space.

The link_ array is used to maintain the threading. There is one thread for each column, and a single thread for all free entries in hrow_ and colels_.

The allocated size of link_ must be at least as large as the allocated size of hrow_ and colels_.

CoinBigIndex free_list_
 First entry in free entries thread. More...
 
int maxlink_
 Allocated size of link_. More...
 
CoinBigIndexlink_
 Thread array. More...
 
Debugging aids

These arrays are allocated only when CoinPresolve is compiled with PRESOLVE_DEBUG defined.

They hold codes which track the reason that a column or row is added to the problem during postsolve.

char * cdone_
 
char * rdone_
 
- Public Attributes inherited from CoinPrePostsolveMatrix
int ncols_
 current number of columns More...
 
int nrows_
 current number of rows More...
 
CoinBigIndex nelems_
 current number of coefficients More...
 
int ncols0_
 Allocated number of columns. More...
 
int nrows0_
 Allocated number of rows. More...
 
CoinBigIndex nelems0_
 Allocated number of coefficients. More...
 
CoinBigIndex bulk0_
 Allocated size of bulk storage for row indices and coefficients. More...
 
double bulkRatio_
 Ratio of bulk0_ to nelems0_; default is 2. More...
 
CoinBigIndexmcstrt_
 Vector of column start positions in hrow_, colels_. More...
 
int * hincol_
 Vector of column lengths. More...
 
int * hrow_
 Row indices (positional correspondence with colels_) More...
 
double * colels_
 Coefficients (positional correspondence with hrow_) More...
 
double * cost_
 Objective coefficients. More...
 
double originalOffset_
 Original objective offset. More...
 
double * clo_
 Column (primal variable) lower bounds. More...
 
double * cup_
 Column (primal variable) upper bounds. More...
 
double * rlo_
 Row (constraint) lower bounds. More...
 
double * rup_
 Row (constraint) upper bounds. More...
 
int * originalColumn_
 Original column numbers. More...
 
int * originalRow_
 Original row numbers. More...
 
double ztolzb_
 Primal feasibility tolerance. More...
 
double ztoldj_
 Dual feasibility tolerance. More...
 
double maxmin_
 Maximization/minimization. More...
 
double * sol_
 Vector of primal variable values. More...
 
double * rowduals_
 Vector of dual variable values. More...
 
double * acts_
 Vector of constraint left-hand-side values (row activity) More...
 
double * rcosts_
 Vector of reduced costs. More...
 
unsigned char * colstat_
 Status of primal variables. More...
 
unsigned char * rowstat_
 Status of constraints. More...
 
CoinMessageHandlerhandler_
 Message handler. More...
 
bool defaultHandler_
 Indicates if the current handler_ is default (true) or not (false). More...
 
CoinMessage messages_
 Standard COIN messages. More...
 

Related Functions

(Note that these are not member functions.)

CoinBigIndex presolve_find_col (int col, CoinBigIndex krs, CoinBigIndex kre, const int *hcol)
 Find position of a column in a row in a row-major matrix. More...
 
CoinBigIndex presolve_find_minor2 (int tgt, CoinBigIndex ks, int majlen, const int *minndxs, const CoinBigIndex *majlinks)
 Find position of a minor index in a major vector in a threaded matrix. More...
 
CoinBigIndex presolve_find_row2 (int row, CoinBigIndex kcs, int collen, const int *hrow, const CoinBigIndex *clinks)
 Find position of a row in a column in a column-major threaded matrix. More...
 
CoinBigIndex presolve_find_minor3 (int tgt, CoinBigIndex ks, int majlen, const int *minndxs, const CoinBigIndex *majlinks)
 Find position of a minor index in a major vector in a threaded matrix. More...
 
CoinBigIndex presolve_find_row3 (int row, CoinBigIndex kcs, int collen, const int *hrow, const CoinBigIndex *clinks)
 Find position of a row in a column in a column-major threaded matrix. More...
 
void presolve_delete_from_major2 (int majndx, int minndx, CoinBigIndex *majstrts, int *majlens, int *minndxs, int *majlinks, CoinBigIndex *free_listp)
 Delete the entry for a minor index from a major vector in a threaded matrix. More...
 
void presolve_delete_from_col2 (int row, int col, CoinBigIndex *mcstrt, int *hincol, int *hrow, int *clinks, CoinBigIndex *free_listp)
 Delete the entry for row row from column col in a column-major threaded matrix. More...
 
void presolve_check_threads (const CoinPostsolveMatrix *obj)
 Checks that column threads agree with column lengths. More...
 
void presolve_check_free_list (const CoinPostsolveMatrix *obj, bool chkElemCnt=false)
 Checks the free list. More...
 
void presolve_check_reduced_costs (const CoinPostsolveMatrix *obj)
 Check stored reduced costs for accuracy and consistency with variable status. More...
 
void presolve_check_duals (const CoinPostsolveMatrix *postObj)
 Check the dual variables for consistency with row activity. More...
 
void presolve_check_sol (const CoinPostsolveMatrix *postObj, int chkColSol=2, int chkRowAct=2, int chkStatus=1)
 Check primal solution and architectural variable status. More...
 
void presolve_check_nbasic (const CoinPostsolveMatrix *postObj)
 Check for the proper number of basic variables. More...
 

Additional Inherited Members

- Public Types inherited from CoinPrePostsolveMatrix
enum  Status {
  isFree = 0x00, basic = 0x01, atUpperBound = 0x02, atLowerBound = 0x03,
  superBasic = 0x04
}
 Enum for status of various sorts. More...
 

Detailed Description

Augments CoinPrePostsolveMatrix with information about the problem that is only needed during postsolve.

The notable point is that the matrix representation is threaded. The representation is column-major and starts with the standard two pairs of arrays: one pair to hold the row indices and coefficients, the second pair to hold the column starting positions and lengths. But the row indices and coefficients for a column do not necessarily occupy a contiguous block in their respective arrays. Instead, a link array gives the position of the next (row index,coefficient) pair. If the row index and value of a coefficient a<p,j> occupy position kp in their arrays, then the position of the next coefficient a<q,j> is found as kq = link[kp].

This threaded representation allows for efficient expansion of columns as rows are reintroduced during postsolve transformations. The basic packed structures are allocated to the expected size of the postsolved matrix, and as new coefficients are added, their location is simply added to the thread for the column.

There is no provision to convert the threaded representation to a packed representation. In the context of postsolve, it's not required. (You did keep a copy of the original matrix, eh?)

The constructors that take an OSI or ClpSimplex as a parameter really should not be here, but for historical reasons they will likely remain for the forseeable future. – lh, 111202 –

Definition at line 1421 of file CoinPresolveMatrix.hpp.

Constructor & Destructor Documentation

CoinPostsolveMatrix::CoinPostsolveMatrix ( int  ncols_alloc,
int  nrows_alloc,
CoinBigIndex  nelems_alloc 
)

`Native' constructor

This constructor creates an empty object which must then be loaded. On the other hand, it doesn't assume that the client is an OsiSolverInterface.

CoinPostsolveMatrix::CoinPostsolveMatrix ( ClpSimplex si,
int  ncols0,
int  nrows0,
CoinBigIndex  nelems0,
double  maxmin_,
double *  sol,
double *  acts,
unsigned char *  colstat,
unsigned char *  rowstat 
)

Clp OSI constructor.

See Clp code for the definition.

CoinPostsolveMatrix::CoinPostsolveMatrix ( OsiSolverInterface si,
int  ncols0,
int  nrows0,
CoinBigIndex  nelems0,
double  maxmin_,
double *  sol,
double *  acts,
unsigned char *  colstat,
unsigned char *  rowstat 
)

Generic OSI constructor.

See OSI code for the definition.

CoinPostsolveMatrix::~CoinPostsolveMatrix ( )

Destructor.

Member Function Documentation

void CoinPostsolveMatrix::assignPresolveToPostsolve ( CoinPresolveMatrix *&  preObj)

Load an empty CoinPostsolveMatrix from a CoinPresolveMatrix.

This routine transfers the contents of the CoinPrePostsolveMatrix object from the CoinPresolveMatrix object to the CoinPostsolveMatrix object and completes initialisation of the CoinPostsolveMatrix object. The empty shell of the CoinPresolveMatrix object is destroyed.

The routine expects an empty CoinPostsolveMatrix object. If handed a loaded object, a lot of memory will leak.

void CoinPostsolveMatrix::check_nbasic ( )

debug

Member Data Documentation

CoinBigIndex CoinPostsolveMatrix::free_list_

First entry in free entries thread.

Definition at line 1501 of file CoinPresolveMatrix.hpp.

int CoinPostsolveMatrix::maxlink_

Allocated size of link_.

Definition at line 1503 of file CoinPresolveMatrix.hpp.

CoinBigIndex* CoinPostsolveMatrix::link_

Thread array.

Within a thread, link_[k] points to the next entry in the thread.

Definition at line 1508 of file CoinPresolveMatrix.hpp.

char* CoinPostsolveMatrix::cdone_

Definition at line 1519 of file CoinPresolveMatrix.hpp.

char* CoinPostsolveMatrix::rdone_

Definition at line 1520 of file CoinPresolveMatrix.hpp.


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