NAME

bcomm, sbcomm, dbcomm, cbcomm, zbcomm - block coordinate matrix-matrix multiply


SYNOPSIS

  SUBROUTINE SBCOMM( TRANSA, MB, N, KB, ALPHA, DESCRA,
 *           VAL, BINDX, BJNDX, BNNZ, LB,
 *           B, LDB, BETA, C, LDC, WORK, LWORK )
  INTEGER*4  TRANSA, MB, N, KB, DESCRA(5), BNNZ, LB,
 *           LDB, LDC, LWORK
  INTEGER*4  BINDX(BNNZ), BJNDX(BNNZ)
  REAL*4     ALPHA, BETA
  REAL*4     VAL(LB*LB*BNNZ), B(LDB,*), C(LDC,*), WORK(LWORK)
  SUBROUTINE DBCOMM( TRANSA, MB, N, KB, ALPHA, DESCRA,
 *           VAL, BINDX, BJNDX, BNNZ, LB,
 *           B, LDB, BETA, C, LDC, WORK, LWORK)
  INTEGER*4  TRANSA, MB, N, KB, DESCRA(5), BNNZ, LB,
 *           LDB, LDC, LWORK
  INTEGER*4  BINDX(BNNZ), BJNDX(BNNZ)
  REAL*8     ALPHA, BETA
  REAL*8     VAL(LB*LB*BNNZ), B(LDB,*), C(LDC,*), WORK(LWORK)
  SUBROUTINE CBCOMM( TRANSA, MB, N, KB, ALPHA, DESCRA,
 *           VAL, BINDX, BJNDX, BNNZ, LB,
 *           B, LDB, BETA, C, LDC, WORK, LWORK )
  INTEGER*4  TRANSA, MB, N, KB, DESCRA(5), BNNZ, LB,
 *           LDB, LDC, LWORK
  INTEGER*4  BINDX(BNNZ), BJNDX(BNNZ)
  COMPLEX*8  ALPHA, BETA
  COMPLEX*8  VAL(LB*LB*BNNZ), B(LDB,*), C(LDC,*), WORK(LWORK)
  SUBROUTINE ZBCOMM( TRANSA, MB, N, KB, ALPHA, DESCRA,
 *           VAL, BINDX, BJNDX, BNNZ, LB,
 *           B, LDB, BETA, C, LDC, WORK, LWORK)
  INTEGER*4  TRANSA, MB, N, KB, DESCRA(5), BNNZ, LB,
 *           LDB, LDC, LWORK
  INTEGER*4  BINDX(BNNZ), BJNDX(BNNZ)
  COMPLEX*16 ALPHA, BETA
  COMPLEX*16 VAL(LB*LB*BNNZ), B(LDB,*), C(LDC,*), WORK(LWORK)


DESCRIPTION

          C <- alpha op(A) B + beta C

 where ALPHA and BETA are scalar, C and B are dense matrices,
 A is a matrix represented in block coordinate format and    
 op( A )  is one  of
 op( A ) = A   or   op( A ) = A'   or   op( A ) = conjg( A' ).
                                    ( ' indicates matrix transpose)


ARGUMENTS

 TRANSA        Indicates how to operate with the sparse matrix
                 0 : operate with matrix
                 1 : operate with transpose matrix
                 2 : operate with the conjugate transpose of matrix.
                     2 is equivalent to 1 if the matrix is real.

 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 (A=A')
                 2 : Hermitian (A= CONJG(A'))
                 3 : Triangular
                 4 : Skew(Anti)-Symmetric (A=-A')
                 5 : Diagonal
                 6 : Skew-Hermitian (A= -CONJG(A'))
               DESCRA(2) upper/lower triangular indicator 
                 1 : lower
                 2 : upper
               DESCRA(3) main diagonal type 
                 0 : non-unit
                 1 : unit
               DESCRA(4) Array base  (NOT IMPLEMENTED)
                 0 : C/C++ compatible
                 1 : Fortran compatible
               DESCRA(5) repeated indices? (NOT IMPLEMENTED)
                 0 : unknown
                 1 : no repeated indices
 VAL()         scalar array of length LB*LB*BNNZ consisting of
               the non-zero block entries of A, in any order.
               Each block is stored in standard column-major form.
 BINDX()       integer array of length BNNZ consisting of the
               block row indices of the block entries of A.
 BJNDX()       integer array of length BNNZ consisting of the
               block column indices of the block entries of A.
 BNNZ          number of block entries
 LB            dimension of dense blocks composing A.
 B()           rectangular array with first dimension LDB.
 LDB           leading dimension of B
 BETA          Scalar parameter
 C()           rectangular array with first dimension LDC.
 LDC           leading dimension of C
 WORK()        scratch array of length LWORK. WORK is not
               referenced in the current version.

 LWORK         length of WORK array. LWORK is not referenced
               in the current version.


SEE ALSO

NIST FORTRAN Sparse Blas User's Guide available at:

http://math.nist.gov/mcsd/Staff/KRemington/fspblas/