HPL_daxpy - Man Page
y := y + alpha * x.
Synopsis
#include "hpl.h"
void HPL_daxpy( const int N, const double ALPHA, const double * X, const int INCX, double * Y, const int INCY );
Description
HPL_daxpy scales the vector x by alpha and adds it to y.
Arguments
- N (local input) const int
On entry, N specifies the length of the vectors x and y. N must be at least zero.
- ALPHA (local input) const double
On entry, ALPHA specifies the scalar alpha. When ALPHA is supplied as zero, then the entries of the incremented array X need not be set on input.
- X (local input) const double *
On entry, X is an incremented array of dimension at least ( 1 + ( n - 1 ) * abs( INCX ) ) that contains the vector x.
- INCX (local input) const int
On entry, INCX specifies the increment for the elements of X. INCX must not be zero.
- Y (local input/output) double *
On entry, Y is an incremented array of dimension at least ( 1 + ( n - 1 ) * abs( INCY ) ) that contains the vector y. On exit, the entries of the incremented array Y are updated with the scaled entries of the incremented array X.
- INCY (local input) const int
On entry, INCY specifies the increment for the elements of Y. INCY must not be zero.
Example
#include "hpl.h"
int main(int argc, char *argv[])
{
double x[3], y[3];
x[0] = 1.0; x[1] = 2.0; x[2] = 3.0;
y[0] = 4.0; y[1] = 5.0; y[2] = 6.0;
HPL_daxpy( 3, 2.0, x, 1, y, 1 );
printf("y=[%f,%f,%f]\n", y[0], y[1], y[2]);
exit(0); return(0);
}
See Also
Referenced By
HPL_dcopy(3), HPL_dscal(3), HPL_dswap(3), HPL_idamax(3).