zig/lib/std/math/complex/acosh.zig
2021-05-08 15:15:30 +03:00

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Zig

// SPDX-License-Identifier: MIT
// Copyright (c) 2015-2021 Zig Contributors
// This file is part of [zig](https://ziglang.org/), which is MIT licensed.
// The MIT license requires this copyright notice to be included in all copies
// and substantial portions of the software.
const std = @import("../../std.zig");
const testing = std.testing;
const math = std.math;
const cmath = math.complex;
const Complex = cmath.Complex;
/// Returns the hyperbolic arc-cosine of z.
pub fn acosh(z: anytype) Complex(@TypeOf(z.re)) {
const T = @TypeOf(z.re);
const q = cmath.acos(z);
return Complex(T).new(-q.im, q.re);
}
const epsilon = 0.0001;
test "complex.cacosh" {
const a = Complex(f32).new(5, 3);
const c = acosh(a);
try testing.expect(math.approxEqAbs(f32, c.re, 2.452914, epsilon));
try testing.expect(math.approxEqAbs(f32, c.im, 0.546975, epsilon));
}