HP MLIB User's Guide Vol. 1 7th Ed.

Chapter 4 Sparse BLAS Operations 443
Block coordinate matrix-matrix multiply SBCOMM/DBCOMM/CBCOMM/ZBCOMM
1: Operate with transpose matrix
2: Operate with conjugate-transpose matrix
mb Number of block rows in matrix A.
n Number of columns in matrix C.
kb Number of block columns in matrix A.
alpha Scalar parameter.
descra( )
Descriptor argument. Five element integer array.
descra(1) Matrix structure.
0: General
1: Symmetric
2: Hermitian
3: Triangular
4: Skew (Anti)-Symmetric
5: Diagonal
descra(2) Upper/Lower triangular indicator.
1: Lower
2: Upper
descra(3) Main diagonal type.
0: Non-unit
1: Unit
descra(4) Array base.
0: C/C++ compatible Not Supported
1: Fortran compatible
descra(5) Repeated indices.
0: Unknown
1: No repeated indices
val( ) Scalar array of length nnz containing matrix entries
stored column-major within each dense block.
bindx( ) Integer array of length bnnz consisting of the block row
indices of the block entries of A.