MatPreallocateSet#

Indicates the locations (rows and columns) in the matrix where nonzeros will be inserted using a local number of the rows and columns

Synopsis#

#include <petscmat.h>
PetscErrorCode MatPreallocateSet(PetscInt nrows, PetscInt *rows,PetscInt ncols, PetscInt *cols,PetscInt *dnz, PetscInt *onz)

Not Collective

Input Parameters#

  • row - the row

  • ncols - the number of columns in the matrix

  • cols - the columns indicated

Output Parameters#

  • dnz - the array that will be passed to the matrix preallocation routines

  • onz - the other array passed to the matrix preallocation routines

(since v3.19)

Notes#

This routine is no longer needed since assembling matrices without explicit preallocation will not be slower than the use of this routine

Do not malloc or free dnz and onz that is handled internally by these routines

This is a MACRO, not a function, because it uses variables declared in MatPreallocateBegin().

See Also#

Matrices, MatPreallocateEnd(), MatPreallocateSet(), MatPreallocateSymmetricSetBlock() MatPreallocateBegin(), MatPreallocateSetLocal()

Level#

deprecated

Location#

include/petscmat.h

Index of all Mat routines
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Index of all manual pages