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Function std.math.trigonometry.atan

Calculates the arc tangent of x, returning a value ranging from -π/2 to π/2.

real atan (
  real x
) pure nothrow @nogc @safe;

double atan (
  double x
) pure nothrow @nogc @safe;

float atan (
  float x
) pure nothrow @nogc @safe;

Special Values
x atan(x) invalid?
±0.0 ±0.0 no
±∞ NAN yes


import std.math.operations : isClose;
import std.math.traits : isIdentical;
import std.math.constants : PI;
import std.math.algebraic : sqrt;

assert(isIdentical(atan(0.0), 0.0));
assert(atan(sqrt(3.0)).isClose(PI / 3));


Walter Bright, Don Clugston, Conversion of CEPHES math library to D by Iain Buclaw and David Nadlinger


Boost License 1.0.