vatan2 - Vector arctangent tan-1(x/y)

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

subroutine vatan2 (n, z, incz, x, incx, y, incy);
subroutine vatan2f(n, z, incz, x, incx, y, incy);

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

z= tan -1(x/y)

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