# MATKAIJ
MATKAIJ = "kaij" - A matrix type to be used to evaluate matrices of form [I \otimes S + A \otimes T], where S is a dense (p \times q) matrix, T is a dense (p \times q) matrix, A is an AIJ  (n \times n) matrix, and I is the identity matrix. The resulting matrix is (np \times nq). S and T are always stored independently on all processes as `PetscScalar` arrays in column-major format.


## Note
A linear system with multiple right-hand sides, AX = B, can be expressed in the KAIJ-friendly form of (A \otimes I) x = b,
where x and b are column vectors containing the row-major representations of X and B.




## See Also
 `MatKAIJSetAIJ()`, `MatKAIJSetS()`, `MatKAIJSetT()`, `MatKAIJGetAIJ()`, `MatKAIJGetS()`, `MatKAIJGetT()`, `MatCreateKAIJ()`

## Level
advanced

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/kaij/kaij.c.html#MATKAIJ">src/mat/impls/kaij/kaij.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex77.c.html">src/ksp/ksp/tutorials/ex77.c.html</A><BR>


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