petsc-3.12.4 2020-02-04
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# MATSEQAIJ

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

### Options Database Keys

-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 Notes

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

### See Also

MatCreateSeqAIJ(), MatSetFromOptions(), MatSetType(), MatCreate(), MatType

### Level

beginner

### Location

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

### Examples

src/mat/examples/tutorials/ex1.c.html
src/mat/examples/tutorials/ex12.c.html
src/ksp/ksp/examples/tutorials/ex59.c.html
src/tao/leastsquares/examples/tutorials/tomography.c.html
Index of all Mat routines
Table of Contents for all manual pages
Index of all manual pages