Contents
djadmm - Jagged diagonal matrix-matrix multiply (modified
Ellpack)
SUBROUTINE DJADMM( TRANSA, M, N, K, ALPHA, DESCRA,
* VAL, INDX, PNTR, MAXNZ, IPERM,
* B, LDB, BETA, C, LDC, WORK, LWORK)
INTEGER TRANSA, M, N, K, DESCRA(5), MAXNZ,
* LDB, LDC, LWORK
INTEGER INDX(NNZ), PNTR(MAXNZ+1), IPERM(M)
DOUBLE PRECISION ALPHA, BETA
DOUBLE PRECISION VAL(NNZ), B(LDB,*), C(LDC,*), WORK(LWORK)
SUBROUTINE DJADMM_64( TRANSA, M, N, K, ALPHA, DESCRA,
* VAL, INDX, PNTR, MAXNZ, IPERM,
* B, LDB, BETA, C, LDC, WORK, LWORK)
INTEGER*8 TRANSA, M, N, K, DESCRA(5), MAXNZ,
* LDB, LDC, LWORK
INTEGER*8 INDX(NNZ), PNTR(MAXNZ+1), IPERM(M)
DOUBLE PRECISION ALPHA, BETA
DOUBLE PRECISION VAL(NNZ), B(LDB,*), C(LDC,*), WORK(LWORK)
where NNZ=PNTR(MAXNZ+1)-PNTR(1)+1 is the number of non-zero elements
F95 INTERFACE
SUBROUTINE JADMM( TRANSA, M, [N], K, ALPHA, DESCRA, VAL, INDX,
* PNTR, MAXNZ, IPERM, B, [LDB], BETA, C, [LDC], [WORK], [LWORK])
INTEGER TRANSA, M, K, MAXNZ
INTEGER, DIMENSION(:) :: DESCRA, INDX, PNTR, IPERM
DOUBLE PRECISION ALPHA, BETA
DOUBLE PRECISION, DIMENSION(:) :: VAL
DOUBLE PRECISION, DIMENSION(:, :) :: B, C
SUBROUTINE JADMM_64( TRANSA, M, [N], K, ALPHA, DESCRA, VAL, INDX,
* PNTR, MAXNZ, IPERM, B, [LDB], BETA, C, [LDC], [WORK], [LWORK])
INTEGER*8 TRANSA, M, K, MAXNZ
INTEGER*8, DIMENSION(:) :: DESCRA, INDX, PNTR, IPERM
DOUBLE PRECISION ALPHA, BETA
DOUBLE PRECISION, DIMENSION(:) :: VAL
DOUBLE PRECISION, DIMENSION(:, :) :: B, C
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 jagged-diagonal format and
op( A ) is one of
op( A ) = A or op( A ) = A' or op( A ) = conjg( A' ).
( ' indicates matrix transpose)
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
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 of length NNZ consisting of entries of A.
VAL can be viewed as a column major ordering of a
row permutation of the Ellpack representation of A,
where the Ellpack representation is permuted so that
the rows are non-increasing in the number of nonzero
entries. Values added for padding in Ellpack are
not included in the Jagged-Diagonal format.
INDX() array of length NNZ consisting of the column indices
of the corresponding entries in VAL.
PNTR() array of length MAXNZ+1, where PNTR(I)-PNTR(1)+1
points to the location in VAL of the first element
in the row-permuted Ellpack represenation of A.
MAXNZ max number of nonzeros elements per row.
IPERM() integer array of length M such that I = IPERM(I'),
where row I in the original Ellpack representation
corresponds to row I' in the permuted representation.
If IPERM(1) = 0, it is assumed by convention that
IPERM(I) = I. IPERM is used to determine the order
in which rows of C are updated.
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.
NIST FORTRAN Sparse Blas User's Guide available at:
http://math.nist.gov/mcsd/Staff/KRemington/fspblas/
"Document for the Basic Linear Algebra Subprograms (BLAS)
Standard", University of Tennessee, Knoxville, Tennessee,
1996:
http://www.netlib.org/utk/papers/sparse.ps