HP MLIB User's Guide Vol. 2 7th Ed.

858 HP MLIB User’s Guide
vsinvsqrt, vdinvsqrt The reciprocal square root of the elements of a vector
Name vsinvsqrt, vdinvsqrt
The reciprocal square root of the elements of a vector
Purpose vsinvsqrt and vdinvsqrt calculate the reciprocal square root of vector elements:
y(i) = 1.0/sqrt(a(i)), for 1 <= i <= n
Usage The Fortran include file math.fi declares interfaces for these subroutines,
suitable for both VMATH and VMATH8. The interfaces are compatible with
Intel’s MKL VML (Vector Math Library).
SUBROUTINE vsinvsqrt(n, a, y)
INTEGER, INTENT(IN) :: n
REAL (KIND=4), DIMENSION(n), INTENT(IN) :: a
REAL (KIND=4), DIMENSION(n), INTENT(OUT):: y
SUBROUTINE vdinvsqrt(n, a, y)
INTEGER, INTENT(IN) :: n
REAL (KIND=8), DIMENSION(n), INTENT(IN) :: a
REAL (KIND=8), DIMENSION(n), INTENT(OUT):: y
Input n Number of elements to be calculated.
a Array of length at least n, specifying the input vector.
Output y Array of length at least n specifying the output vector.