reader_ccg.c File Reference

Detailed Description

Graph file reader (actually, only a writer)

Author

Marc Pfetsch

Write a weighted column/variable graph, i.e., the nodes correspond to the columns (variables) of the constraint matrix. Two nodes are adjacent if the corresponding columns/variables appear in a common row/constraint (with nonzero coefficient). The weight is obtained by summing for each row that produces an edge the absolute values of coefficients in the row; hence, we avoid parallel edges.

This graph gives an indication of the connectivity structure of the constraint matrix.

The graph is output in DIMACS graph format.

Definition in file reader_ccg.c.

#include "blockmemshell/memory.h"
#include "scip/cons_knapsack.h"
#include "scip/cons_linear.h"
#include "scip/cons_logicor.h"
#include "scip/cons_setppc.h"
#include "scip/cons_varbound.h"
#include "scip/pub_cons.h"
#include "scip/pub_message.h"
#include "scip/pub_reader.h"
#include "scip/pub_var.h"
#include "scip/reader_ccg.h"
#include "scip/scip_cons.h"
#include "scip/scip_mem.h"
#include "scip/scip_message.h"
#include "scip/scip_reader.h"
#include "scip/scip_var.h"
#include <string.h>

Go to the source code of this file.

Macros
#define	READER_NAME   "ccgreader"
#define	READER_DESC   "file writer for column connectivity graph file format"
#define	READER_EXTENSION   "ccg"

Typedefs
typedef struct sparseGraph	SparseGraph

Functions
static SCIP_RETCODE	initGraph (SCIP *scip, SparseGraph *G, unsigned int nNodes, unsigned int initSize)
static void	freeGraph (SCIP *scip, SparseGraph *G)
static SCIP_RETCODE	ensureEdgeCapacity (SCIP *scip, SparseGraph *G, unsigned int node)
static SCIP_RETCODE	getActiveVariables (SCIP *scip, SCIP_VAR **vars, SCIP_Real *scalars, int *nvars, SCIP_Real *constant, SCIP_Bool transformed)
static SCIP_RETCODE	createEdgesFromRow (SCIP *scip, SCIP_VAR **vars, SCIP_Real *vals, int nvars, SparseGraph *G)
static SCIP_RETCODE	handleLinearCons (SCIP *scip, SCIP_VAR **vars, SCIP_Real *vals, int nvars, SCIP_Bool transformed, SparseGraph *G)
static	SCIP_DECL_READERCOPY (readerCopyCcg)
static	SCIP_DECL_READERWRITE (readerWriteCcg)
SCIP_RETCODE	SCIPincludeReaderCcg (SCIP *scip)
SCIP_RETCODE	SCIPwriteCcg (SCIP *scip, FILE *file, const char *name, SCIP_Bool transformed, SCIP_VAR **vars, int nvars, SCIP_CONS **conss, int nconss, SCIP_RESULT *result)

Macro Definition Documentation

READER_NAME

#define READER_NAME   "ccgreader"

Definition at line 61 of file reader_ccg.c.

READER_DESC

#define READER_DESC   "file writer for column connectivity graph file format"

Definition at line 62 of file reader_ccg.c.

READER_EXTENSION

#define READER_EXTENSION   "ccg"

Definition at line 63 of file reader_ccg.c.

Typedef Documentation

SparseGraph

typedef struct sparseGraph SparseGraph

Definition at line 81 of file reader_ccg.c.

Function Documentation

initGraph()

static SCIP_RETCODE initGraph ( SCIP *  scip, SparseGraph *  G, unsigned int  nNodes, unsigned int  initSize  )

static

initialize graph

Parameters

scip	SCIP data structure
G	graph to free
nNodes	number of nodes
initSize	initial size of lists

Definition at line 90 of file reader_ccg.c.

References SCIP_CALL, SCIP_OKAY, and SCIPallocBufferArray.

Referenced by SCIPwriteCcg().

freeGraph()

static void freeGraph ( SCIP *  scip, SparseGraph *  G  )

static

frees graph

Parameters

scip	SCIP data structure
G	graph to free

Definition at line 124 of file reader_ccg.c.

References SCIPfreeBufferArray.

Referenced by SCIPwriteCcg().

ensureEdgeCapacity()

static SCIP_RETCODE ensureEdgeCapacity ( SCIP *  scip, SparseGraph *  G, unsigned int  node  )

static

check whether there is enough capacity for one additional edge in the given adjacency list

Parameters

scip	SCIP data structure
G	graph
node	list for node

Definition at line 146 of file reader_ccg.c.

References SCIP_CALL, SCIP_OKAY, and SCIPreallocBufferArray.

Referenced by createEdgesFromRow().

getActiveVariables()

static SCIP_RETCODE getActiveVariables ( SCIP *  scip, SCIP_VAR **  vars, SCIP_Real *  scalars, int *  nvars, SCIP_Real *  constant, SCIP_Bool  transformed  )

static

transforms given variables, scalars, and constant to the corresponding active variables, scalars, and constant

Parameters

scip	SCIP data structure
vars	vars array to get active variables for
scalars	scalars a_1, ..., a_n inrc/scip/reader_graph.c linear sum a_1*x_1 + ... + a_n*x_n + c
nvars	pointer to number of variables and values in vars and vals array
constant	pointer to constant c in linear sum a_1*x_1 + ... + a_n*x_n + c
transformed	transformed constraint?

Definition at line 167 of file reader_ccg.c.

References NULL, scalars, SCIP_CALL, SCIP_OKAY, SCIPgetProbvarLinearSum(), SCIPreallocBufferArray, and SCIPvarGetOrigvarSum().

Referenced by handleLinearCons().

createEdgesFromRow()

static SCIP_RETCODE createEdgesFromRow ( SCIP *  scip, SCIP_VAR **  vars, SCIP_Real *  vals, int  nvars, SparseGraph *  G  )

static

Parameters

scip	SCIP data structure
vars	array of constraint variables
vals	array of constraint values
nvars	number of constraint variables
G	graph

Definition at line 212 of file reader_ccg.c.

References a, ABS, ensureEdgeCapacity(), NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPvarGetProbindex(), and w.

Referenced by handleLinearCons().

handleLinearCons()

static SCIP_RETCODE handleLinearCons ( SCIP *  scip, SCIP_VAR **  vars, SCIP_Real *  vals, int  nvars, SCIP_Bool  transformed, SparseGraph *  G  )

static

handle given linear constraint information

Parameters

scip	SCIP data structure
vars	array of variables
vals	array of coefficients values (or NULL if all coefficient values are 1)
nvars	number of variables
transformed	transformed constraint?
G	graph

Definition at line 298 of file reader_ccg.c.

References createEdgesFromRow(), getActiveVariables(), NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPduplicateBufferArray, and SCIPfreeBufferArray.

Referenced by SCIPwriteCcg().

SCIP_DECL_READERCOPY()

static SCIP_DECL_READERCOPY ( readerCopyCcg  )

static

copy method for reader plugins (called when SCIP copies plugins)

Definition at line 349 of file reader_ccg.c.

References NULL, READER_NAME, SCIP_CALL, SCIP_OKAY, SCIPincludeReaderCcg(), and SCIPreaderGetName().

SCIP_DECL_READERWRITE()

static SCIP_DECL_READERWRITE ( readerWriteCcg  )

static

problem writing method of reader

Definition at line 364 of file reader_ccg.c.

References SCIP_CALL, SCIP_OKAY, and SCIPwriteCcg().