MatBDiagGetData

Gets the data for the block diagonal matrix format. For the parallel case, this returns information for the local submatrix.

int MatBDiagGetData(Mat mat,int *nd,int *bs,int **diag,int **bdlen,PetscScalar ***diagv)

mat -the matrix, stored in block diagonal format.

Not Collective

    diag = i/bs - j/bs  (integer division)

Set diag=PETSC_NULL on input for PETSc to dynamically allocate memory as needed (expensive).

	m	- number of rows
	n	- number of columns
	nd	- number of block diagonals
	bs	- each element of a diagonal is an bs x bs dense matrix
	bdlen	- array of total block lengths of block diagonals
	diag	- optional array of block diagonal numbers (length nd). For a matrix element A[i,j], where i=row and j=column, the diagonal number is
	diagv	- pointer to actual diagonals (in same order as diag array),

See the users manual for further details regarding this storage format.

matrix, block, diagonal, get, data