petsc-3.3-p7 2013-05-11

MatIJGetMaxRowSize

 returns the largest number of nonzero columns in all of this processor's rows. If MatIJ (equivalently, the underlying graph) is regarded as a multivalued mapping on integers, then the result is the size of the largest set among the images of this processor's indices. Not collective.

Synopsis

#undef __FUNCT__  
#define __FUNCT__ "MatIJGetMaxRowSize"
PetscErrorCode MatIJGetMaxRowSize(Mat A, PetscInt *maxsize)

Input parameters

A - pseudograph

Output parameters

maxsize - the size of the largest image set

Notes

This routine is useful for preallocating arrays to hold the images of the local indices:- if an array of the largest image size is allocated, it can be used for repeatedly computing the images of the local indices.
This routine will fail for an unassembled matrix.-

See Also

MATIJ, MatIJGetImage(), MatIJGetSupport(), MatIJMapI(), MatIJMapIJ(), MatIJMapIW(), MatIJMapIJW()

Level:advanced
Location:src/mat/impls/ij/matij.c
Index of all Mat routines
Table of Contents for all manual pages
Index of all manual pages