sla_syamv - nite matrix to calculate error bounds
SUBROUTINE SLA_SYAMV(UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY) REAL ALPHA, BETA INTEGER INCX, INCY, LDA, N, UPLO REAL A(LDA,*), X(*), Y(*) SUBROUTINE SLA_SYAMV_64(UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY) REAL ALPHA, BETA INTEGER*8 INCX, INCY, LDA, N, UPLO REAL A(LDA,*), X(*), Y(*) F95 INTERFACE SUBROUTINE LA_SYAMV(UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY) REAL, DIMENSION(:,:) :: A INTEGER :: UPLO, N, LDA, INCX, INCY REAL, DIMENSION(:) :: X, Y REAL :: ALPHA, BETA SUBROUTINE LA_SYAMV_64(UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY) REAL, DIMENSION(:,:) :: A INTEGER(8) :: UPLO, N, LDA, INCX, INCY REAL, DIMENSION(:) :: X, Y REAL :: ALPHA, BETA C INTERFACE #include <sunperf.h> void sla_syamv (int uplo, int n, float alpha, float *a, int lda, float *x, int incx, float beta, float *y, int incy); void sla_syamv_64 (long uplo, long n, float alpha, float *a, long lda, float *x, long incx, float beta, float *y, long incy);
Oracle Solaris Studio Performance Library sla_syamv(3P) NAME sla_syamv - compute a matrix-vector product using a symmetric indefi- nite matrix to calculate error bounds SYNOPSIS SUBROUTINE SLA_SYAMV(UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY) REAL ALPHA, BETA INTEGER INCX, INCY, LDA, N, UPLO REAL A(LDA,*), X(*), Y(*) SUBROUTINE SLA_SYAMV_64(UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY) REAL ALPHA, BETA INTEGER*8 INCX, INCY, LDA, N, UPLO REAL A(LDA,*), X(*), Y(*) F95 INTERFACE SUBROUTINE LA_SYAMV(UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY) REAL, DIMENSION(:,:) :: A INTEGER :: UPLO, N, LDA, INCX, INCY REAL, DIMENSION(:) :: X, Y REAL :: ALPHA, BETA SUBROUTINE LA_SYAMV_64(UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY) REAL, DIMENSION(:,:) :: A INTEGER(8) :: UPLO, N, LDA, INCX, INCY REAL, DIMENSION(:) :: X, Y REAL :: ALPHA, BETA C INTERFACE #include <sunperf.h> void sla_syamv (int uplo, int n, float alpha, float *a, int lda, float *x, int incx, float beta, float *y, int incy); void sla_syamv_64 (long uplo, long n, float alpha, float *a, long lda, float *x, long incx, float beta, float *y, long incy); PURPOSE sla_syamv performs the matrix-vector operation y := alpha*abs(A)*abs(x) + beta*abs(y), where alpha and beta are scalars, x and y are vectors and A is an n by n symmetric matrix. This function is primarily used in calculating error bounds. To pro- tect against underflow during evaluation, components in the resulting vector are perturbed away from zero by (N+1) times the underflow threshold. To prevent unnecessarily large errors for block-structure embedded in general matrices, "symbolically" zero components are not perturbed. A zero entry is considered "symbolic" if all multiplica- tions involved in computing that entry have at least one zero multipli- cand. ARGUMENTS UPLO (input) UPLO is INTEGER On entry, UPLO specifies whether the upper or lower triangu- lar part of the array A is to be referenced as follows: UPLO = BLAS_UPPER Only the upper triangular part of A is to be referenced. UPLO = BLAS_LOWER Only the lower triangular part of A is to be referenced. Unchanged on exit. N (input) N is INTEGER On entry, N specifies the number of columns of the matrix A. N must be at least zero. Unchanged on exit. ALPHA (input) ALPHA is REAL On entry, ALPHA specifies the scalar alpha. Unchanged on exit. A (input) A is REAL array of DIMENSION ( LDA, n ) Before entry, the leading m by n part of the array A must contain the matrix of coefficients. Unchanged on exit. LDA (input) 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, n ). Unchanged on exit. X (input) X is REAL array, dimension ( 1 + ( n - 1 )*abs( INCX ) ) Before entry, the incremented array X must contain the vector x. Unchanged on exit. INCX (input) INCX is INTEGER On entry, INCX specifies the increment for the elements of X. INCX must not be zero. Unchanged on exit. BETA (input) BETA is REAL On entry, BETA specifies the scalar beta. When BETA is sup- plied as zero then Y need not be set on input. Unchanged on exit. Y (input/output) Y is REAL array, dimension ( 1 + ( n - 1 )*abs( INCY ) ) 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 (input) INCY is INTEGER On entry, INCY specifies the increment for the elements of Y. INCY must not be zero. Unchanged on exit. 7 Nov 2015 sla_syamv(3P)