root / man / man3 / HPL_dscal.3 @ 1
Historique | Voir | Annoter | Télécharger (1,41 ko)
| 1 |
.TH HPL_dscal 3 "September 10, 2008" "HPL 2.0" "HPL Library Functions" |
|---|---|
| 2 |
.SH NAME |
| 3 |
HPL_dscal \- x = alpha * x. |
| 4 |
.SH SYNOPSIS |
| 5 |
\fB\&#include "hpl.h"\fR |
| 6 |
|
| 7 |
\fB\&void\fR |
| 8 |
\fB\&HPL_dscal(\fR |
| 9 |
\fB\&const int\fR |
| 10 |
\fI\&N\fR, |
| 11 |
\fB\&const double\fR |
| 12 |
\fI\&ALPHA\fR, |
| 13 |
\fB\&double *\fR |
| 14 |
\fI\&X\fR, |
| 15 |
\fB\&const int\fR |
| 16 |
\fI\&INCX\fR |
| 17 |
\fB\&);\fR |
| 18 |
.SH DESCRIPTION |
| 19 |
\fB\&HPL_dscal\fR |
| 20 |
scales the vector x by alpha. |
| 21 |
.SH ARGUMENTS |
| 22 |
.TP 8 |
| 23 |
N (local input) const int |
| 24 |
On entry, N specifies the length of the vector x. N must be |
| 25 |
at least zero. |
| 26 |
.TP 8 |
| 27 |
ALPHA (local input) const double |
| 28 |
On entry, ALPHA specifies the scalar alpha. When ALPHA is |
| 29 |
supplied as zero, then the entries of the incremented array X |
| 30 |
need not be set on input. |
| 31 |
.TP 8 |
| 32 |
X (local input/output) double * |
| 33 |
On entry, X is an incremented array of dimension at least |
| 34 |
( 1 + ( n - 1 ) * abs( INCX ) ) that contains the vector x. |
| 35 |
On exit, the entries of the incremented array X are scaled |
| 36 |
by the scalar alpha. |
| 37 |
.TP 8 |
| 38 |
INCX (local input) const int |
| 39 |
On entry, INCX specifies the increment for the elements of X. |
| 40 |
INCX must not be zero. |
| 41 |
.SH EXAMPLE |
| 42 |
\fI\&#include "hpl.h"\fR |
| 43 |
|
| 44 |
int main(int argc, char *argv[]) |
| 45 |
.br |
| 46 |
{
|
| 47 |
.br |
| 48 |
double x[3]; |
| 49 |
.br |
| 50 |
x[0] = 1.0; x[1] = 2.0; x[2] = 3.0; |
| 51 |
.br |
| 52 |
HPL_dscal( 3, 2.0, x, 1 ); |
| 53 |
.br |
| 54 |
printf("x=[%f,%f,%f]\en", x[0], x[1], x[2]);
|
| 55 |
.br |
| 56 |
exit(0); return(0); |
| 57 |
.br |
| 58 |
} |
| 59 |
.SH SEE ALSO |
| 60 |
.BR HPL_daxpy \ (3), |
| 61 |
.BR HPL_dcopy \ (3), |
| 62 |
.BR HPL_dswap \ (3). |