HPL_dscal man page

HPL_dscal — x = alpha * x.


#include "hpl.h"
 void HPL_dscal( const int N, const double ALPHA, double * X, const int INCX );


HPL_dscal scales the vector x by alpha.


N       (local input)           const int

On entry, N specifies the length of the vector x. 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/output)    double *

On entry,  X  is an incremented array of dimension  at  least ( 1 + ( n - 1 ) * abs( INCX ) )  that  contains the vector x. On exit, the entries of the incremented array  X  are  scaled by the scalar alpha.

INCX    (local input)           const int

On entry, INCX specifies the increment for the elements of X. INCX must not be zero.


#include "hpl.h"
 int main(int argc, char *argv[])
  double x[3];
  x[0] = 1.0; x[1] = 2.0; x[2] = 3.0;
  HPL_dscal( 3, 2.0, x, 1 );
  printf("x=[%f,%f,%f]\n", x[0], x[1], x[2]);
  exit(0); return(0);

See Also

HPL_daxpy (3), HPL_dcopy (3), HPL_dswap (3).


October 26, 2012 HPL 2.1 HPL Library Functions