Skip to main content
`Ctrl`+`K`

# MATSEQAIJ

MATSEQAIJ = “seqaij” - A matrix type to be used for sequential sparse matrices, based on compressed sparse row format.

## Options Database Key

- -mat_type seqaij - sets the matrix type to “seqaij” during a call to MatSetFromOptions()

## Notes

`MatSetValues()` may be called for this matrix type with a `NULL` argument for the numerical values, in this case the values associated with the rows and columns one passes in are set to zero in the matrix

`MatSetOptions`(,`MAT_STRUCTURE_ONLY`,`PETSC_TRUE`) may be called for this matrix type. In this no space is allocated for the nonzero entries and any entries passed with `MatSetValues()` are ignored

## Developer Note

It would be nice if all matrix formats supported passing `NULL` in for the numerical values

## See Also

Matrices, `Mat`, `MatCreateSeqAIJ()`, `MatSetFromOptions()`, `MatSetType()`, `MatCreate()`, `MatType`, `MATSELL`, `MATSEQSELL`, `MATMPISELL`

## Level

beginner

## Location

src/mat/impls/aij/seq/aij.c

## Examples

src/ksp/ksp/tutorials/ex59.c
src/ksp/ksp/tutorials/ex76.c
src/ksp/ksp/tutorials/ex88f.F90
src/tao/leastsquares/tutorials/tomography.c
src/ksp/ksp/tutorials/ex83f.F90
src/mat/tutorials/ex12.c
src/mat/tutorials/ex1.c

Index of all Mat routines
Table of Contents for all manual pages
Index of all manual pages