MatHeaderReplace#

Replaces the internal data of matrix A by the internal data of matrix C while deleting the outer wrapper of C

Synopsis#

#include "petscmat.h"  
PetscErrorCode MatHeaderReplace(Mat A, Mat *C)

Input Parameters#

A - a Mat whose internal data is to be replaced
C - the Mat providing new internal data for A

Example Usage:

  Mat C;
  MatCreateSeqAIJWithArrays(..., &C);
  MatHeaderReplace(A, &C);
  // C has been destroyed and A contains the matrix entries of C

Note#

This can be used inside a function provided to SNESSetJacobian(), TSSetRHSJacobian(), or TSSetIJacobian() in cases where the user code computes an entirely new sparse matrix (generally with a different nonzero pattern) for each Newton update. It is usually better to reuse the matrix structure of A instead of constructing an entirely new one.

Developer Note#

This is somewhat different from MatHeaderMerge() it would be nice to merge the code

Level#

advanced

Location#

src/mat/utils/gcreate.c

Examples#

src/ksp/ksp/tutorials/ex77.c

Index of all Mat routines
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Index of all manual pages