Digital

Name

vcos_sin − Vector cosine and sine

FORMAT

VCOS_SIN (x, incx, y, incy, z, incz, n)

Arguments

xreal∗8
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.

incxinteger∗4
On entry, the increment for the array X. As incx > 0, vector x is stored forward in the array, so that x(i) is stored in location X(1+(i-1)∗incx).
On exit, incx is unchanged.

yreal∗8
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; y(i) is replaced by cos(x(i)).

incyinteger∗4
On entry, the increment for the array Y. As incy > 0, vector y is stored forward in the array, so that y(i) is stored in location Y(1+(i-1)∗incy).
On exit, incy is unchanged.

zreal∗8
On entry, a one-dimensional array Z of length at least (1+(n-1)∗incz).
On exit, if n <= 0, z is unchanged. If n > 0, z is overwritten; z(i) is replaced by sin(x(i)).

inczinteger∗4
On entry, the increment for the array Z. As incz > 0, vector z is stored forward in the array, so that z(i) is stored in location Z(1+(i-1)∗incz).
On exit, incz is unchanged.

ninteger∗4
On entry, the number of elements to process.
On exit, n is unchanged.

Description

The VCOS_SIN function computes the cosine and sine of n elements of a vector as follows:

y(i) = cos(x(i))
z(i) = sin(x(i))

where x, y and z are vectors. If both the sine and the cosine of a vector are required, then this routine is faster than calling VCOS and VSIN separately. 

Example

INTEGER∗4 N, INCX, INCY
REAL∗8 X(20), Y(20), z(20)
INCX = 1
INCY = 1
INCZ = 1
N = 20
CALL VCOS_SIN(X,INCX,Y,INCY,Z,INCZ,N)

This FORTRAN code shows how the cosine and sine of all elements of the real vector x are obtained and set equal to the corresponding elements of the vectors y and z, respectively.