vatanpi - Vector arctangent tan-1(x)/π

Math Vector Library
Programming Reference Manual Fortran
Version 1.0 DD-00002-110

subroutine vatanpi (n, y, incy, x, incx);
subroutine vatanpif(n, y, incy, x, incx);

Given an input vector $x$ and a result vector $y$ , this function computes:

y= tan -1(x)/π

N - INTEGER: ENTRY: Number of elements of $x$ and $y$ .
CONSTRAINT: $n ≥1$ .
Y - ARRAY OF REAL: EXIT: Result vector $y$ .
CONSTRAINT: Must contain $n× incy$ elements.
CONSTRAINT: Must not overlap with array $x$ .
INCY - INTEGER: ENTRY: Stride for the vector $y$ .
CONSTRAINT: $incy> 0$ .
X - ARRAY OF REAL: ENTRY: Input vector $x$ .
CONSTRAINT: Must contain $n× incx$ elements.
CONSTRAINT: Must not overlap with array $y$ .
INCX - INTEGER: ENTRY: Stride for the vector $x$ .
CONSTRAINT: $incx> 0$ .