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"

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()

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 i, SCIP_CALL, SCIP_OKAY, and SCIPallocBufferArray.

Referenced by SCIPwriteCcg().

◆ freeGraph()

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 i, and SCIPfreeBufferArray.

Referenced by SCIPwriteCcg().

◆ ensureEdgeCapacity()

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()

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_1x_1 + ... + a_nx_n + c
nvars	pointer to number of variables and values in vars and vals array
constant	pointer to constant c in linear sum a_1x_1 + ... + a_nx_n + c
transformed	transformed constraint?

Definition at line 167 of file reader_ccg.c.

References assert(), NULL, nvars, scalars, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPgetProbvarLinearSum(), SCIPreallocBufferArray, SCIPvarGetOrigvarSum(), and vars.

Referenced by handleLinearCons().

◆ createEdgesFromRow()

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, assert(), ensureEdgeCapacity(), i, NULL, nvars, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPvarGetProbindex(), vars, and w.

Referenced by handleLinearCons().

◆ handleLinearCons()

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 assert(), createEdgesFromRow(), getActiveVariables(), NULL, nvars, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPduplicateBufferArray, SCIPfreeBufferArray, and vars.

Referenced by SCIPwriteCcg().

◆ SCIP_DECL_READERCOPY()

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

◆ SCIP_DECL_READERWRITE()

SCIP_DECL_READERWRITE ( readerWriteCcg )

static

problem writing method of reader

Definition at line 364 of file reader_ccg.c.

References nvars, result, SCIP_CALL, SCIP_OKAY, SCIPwriteCcg(), and vars.

Detailed Description

Macros

Functions

Macro Definition Documentation

◆ READER_NAME

◆ READER_DESC

◆ READER_EXTENSION

Typedef Documentation

◆ SparseGraph

Function Documentation

◆ initGraph()

◆ freeGraph()

◆ ensureEdgeCapacity()

◆ getActiveVariables()

◆ createEdgesFromRow()

◆ handleLinearCons()

◆ SCIP_DECL_READERCOPY()

◆ SCIP_DECL_READERWRITE()