sgemv.f man page
subroutine sgemv (TRANS, M, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY)
subroutine sgemv (character TRANS, integer M, integer N, real ALPHA, real, dimension(lda,*) A, integer LDA, real, dimension(*) X, integer INCX, real BETA, real, dimension(*) Y, integer INCY)
SGEMV performs one of the matrix-vector operations y := alpha*A*x + beta*y, or y := alpha*A**T*x + beta*y, where alpha and beta are scalars, x and y are vectors and A is an m by n matrix.
TRANS is CHARACTER*1 On entry, TRANS specifies the operation to be performed as follows: TRANS = 'N' or 'n' y := alpha*A*x + beta*y. TRANS = 'T' or 't' y := alpha*A**T*x + beta*y. TRANS = 'C' or 'c' y := alpha*A**T*x + beta*y.
M is INTEGER On entry, M specifies the number of rows of the matrix A. M must be at least zero.
N is INTEGER On entry, N specifies the number of columns of the matrix A. N must be at least zero.
ALPHA is REAL On entry, ALPHA specifies the scalar alpha.
A is REAL array, dimension ( LDA, N ) Before entry, the leading m by n part of the array A must contain the matrix of coefficients.
LDA is INTEGER On entry, LDA specifies the first dimension of A as declared in the calling (sub) program. LDA must be at least max( 1, m ).
X is REAL array, dimension at least ( 1 + ( n - 1 )*abs( INCX ) ) when TRANS = 'N' or 'n' and at least ( 1 + ( m - 1 )*abs( INCX ) ) otherwise. Before entry, the incremented array X must contain the vector x.
INCX is INTEGER On entry, INCX specifies the increment for the elements of X. INCX must not be zero.
BETA is REAL On entry, BETA specifies the scalar beta. When BETA is supplied as zero then Y need not be set on input.
Y is REAL array, dimension at least ( 1 + ( m - 1 )*abs( INCY ) ) when TRANS = 'N' or 'n' and at least ( 1 + ( n - 1 )*abs( INCY ) ) otherwise. Before entry with BETA non-zero, the incremented array Y must contain the vector y. On exit, Y is overwritten by the updated vector y.
INCY is INTEGER On entry, INCY specifies the increment for the elements of Y. INCY must not be zero.
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
Level 2 Blas routine. The vector and matrix arguments are not referenced when N = 0, or M = 0 -- Written on 22-October-1986. Jack Dongarra, Argonne National Lab. Jeremy Du Croz, Nag Central Office. Sven Hammarling, Nag Central Office. Richard Hanson, Sandia National Labs.
Definition at line 158 of file sgemv.f.
Generated automatically by Doxygen for LAPACK from the source code.
The man page sgemv(3) is an alias of sgemv.f(3).