CXML
svcal, dvcal, cvcal, zvcal, csvcal, zdvcal
Product of a scalar and a
vector
FORMAT
{S,D,C,Z}VCAL (n, alpha, x, incx, y, incy) CSVCAL (n, alpha, x, incx, y,
incy) ZDVCAL (n, alpha, x, incx, y, incy)
Arguments
n integer*4
On entry, the number of elements of the vector x.
On exit, n is unchanged.
alpha real*4 | real*8 | complex*8 | complex*16
On entry, the scalar multiplier alpha.
On exit, alpha is unchanged.
x real*4 | real*8 | complex*8 | complex*16
On entry, a one-dimensional array X of length at least
(1+(n-1)*|incx|), containing the elements of the vector
x.
On exit, x is unchanged.
incx integer*4
On entry, the increment for the array X.
If incx > 0, vector x is stored forward in the array,
so that x(i) is stored in location X(1+(i-1)*incx).
If incx < 0, vector x is stored backward in the array,
so that x(i) is stored in location X(1+(n-i)*|incx|).
If incx = 0, only the first element is accessed.
On exit, incx is unchanged.
y real*4 | real*8 | complex*8 | complex*16
On entry, a one-dimensional array Y of length at least
(1+(n-1)*|incy|).
On exit, if n<=0, y is unchanged. If n > 0, y is
overwritten; each element y(i) is replaced by
alpha*x(i).
incy integer*4
On entry, the increment for the array Y.
If incy >= 0, vector y is stored forward in the array,
so that y(i) is stored in location Y(1+(i-1)*incy)
If incy < 0, vector y is stored backward in the array,
so that y(i) is stored in location Y(1+(n-i)*|incy|).
On exit, incy is unchanged.
Description
SVCAL and DVCAL compute the product of a real scalar and a real vector, in
single or double precision. CVCAL and ZVCAL compute the product of a
complex scalar and a complex vector, in single or double precision. CSVCAL
and ZDVCAL compute the product of a real scalar and a complex vector in
single or double precision.
These subprograms multiply each element of a vector by a scalar value,
returning the result in vector y: y = alpha*x
If incy = 0, the result is unpredictable. If incx = 0, each element in y
is equal to ALPHA*X(1).
If alpha = 0, the computation is a time-consuming way of setting all
elements of the vector y equal to zero. Use the _SET routines to perform
that operation.
EXAMPLES
INTEGER*4 N, INCX, INCY
REAL*4 X(20), Y(40), alpha
INCX = 1
INCY = 2
alpha = 2.0
N = 20
CALL SVCAL(N,alpha,X,INCX,Y,INCY)
This FORTRAN example shows how to scale a vector x by 2.0. Vector y is set
equal to the result.
INTEGER*4 N, INCX, INCY
COMPLEX*8 X(20), Y(40), alpha
INCX = 1
INCY = 2
alpha = (5.0, 1.0)
N = 20
CALL CVCAL(N,alpha,X,INCX,Y,INCY)
This FORTRAN example shows how to scale a vector x by the complex number
(5.0,1.0). Vector y is set equal to the result.
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