NAME

skymm, sskymm, dskymm, cskymm, zskymm - Skyline format matrix-matrix multiply

SYNOPSIS

  SUBROUTINE SSKYMM( TRANSA, M, N, K, ALPHA, DESCRA,
 *           VAL, PNTR, 
 *           B, LDB, BETA, C, LDC, WORK, LWORK )
  INTEGER*4  TRANSA, M, N, K, DESCRA(5),
 *           LDB, LDC, LWORK
  INTEGER*4  PNTR(*),
  REAL*4     ALPHA, BETA
  REAL*4     VAL(NNZ), B(LDB,*), C(LDC,*), WORK(LWORK)

  SUBROUTINE DSKYMM( TRANSA, M, N, K, ALPHA, DESCRA,
 *           VAL, PNTR, 
 *           B, LDB, BETA, C, LDC, WORK, LWORK)
  INTEGER*4  TRANSA, M, N, K, DESCRA(5),
 *           LDB, LDC, LWORK
  INTEGER*4  PNTR(*),
  REAL*8     ALPHA, BETA
  REAL*8     VAL(NNZ), B(LDB,*), C(LDC,*), WORK(LWORK)

  SUBROUTINE CSKYMM( TRANSA, M, N, K, ALPHA, DESCRA,
 *           VAL, PNTR, 
 *           B, LDB, BETA, C, LDC, WORK, LWORK )
  INTEGER*4  TRANSA, M, N, K, DESCRA(5),
 *           LDB, LDC, LWORK
  INTEGER*4  PNTR(*),
  COMPLEX*8  ALPHA, BETA
  COMPLEX*8  VAL(NNZ), B(LDB,*), C(LDC,*), WORK(LWORK)

  SUBROUTINE DSKYMM( TRANSA, M, N, K, ALPHA, DESCRA,
 *           VAL, PNTR, 
 *           B, LDB, BETA, C, LDC, WORK, LWORK)
  INTEGER*4  TRANSA, M, N, K, DESCRA(5),
 *           LDB, LDC, LWORK
  INTEGER*4  PNTR(*),
  COMPLEX*16 ALPHA, BETA
  COMPLEX*16 VAL(NNZ), B(LDB,*), C(LDC,*), WORK(LWORK)

  where NNZ = PNTR(M+1)-PNTR(1) (upper triangular)
        NNZ = PNTR(K+1)-PNTR(1) (lower triangular)
        PNTR() size = (M+1) (upper triangular)
        PNTR() size = (K+1) (lower triangular)

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 skyline 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 matrix is real.

 M             Number of rows in matrix A

 N             Number of columns in matrix C

 K             Number of columns in matrix A

 ALPHA         Scalar parameter

 DESCRA()      Descriptor argument.  Five element integer array
               DESCRA(1) matrix structure
                 0 : general (NOT SUPPORTED)
                 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()         array contain the nonzeros of A in skyline profile form.
               Row-oriented if DESCRA(2) = 1 (lower triangular), 
               column oriented if DESCRA(2) = 2 (upper triangular).

 PNTR()        integer array of length M+1 (lower triangular) or
               K+1 (upper triangular) such that PNTR(I)-PNTR(1)+1
               points to the location in VAL of the first element of
               the skyline profile in row (column) I.

 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.

NOTES/BUGS

The SKY data structure is not supported for a general matrix structure (DESCRA(1)=0).

NAME

SYNOPSIS

DESCRIPTION

ARGUMENTS

SEE ALSO

NOTES/BUGS