zig/std/math/complex/asin.zig

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Zig

const std = @import("../../index.zig");
const debug = std.debug;
const math = std.math;
const cmath = math.complex;
const Complex = cmath.Complex;
pub fn asin(z: var) Complex(@typeOf(z.re)) {
const T = @typeOf(z.re);
const x = z.re;
const y = z.im;
const p = Complex(T).new(1.0 - (x - y) * (x + y), -2.0 * x * y);
const q = Complex(T).new(-y, x);
const r = cmath.log(q.add(cmath.sqrt(p)));
return Complex(T).new(r.im, -r.re);
}
const epsilon = 0.0001;
test "complex.casin" {
const a = Complex(f32).new(5, 3);
const c = asin(a);
debug.assert(math.approxEq(f32, c.re, 1.023822, epsilon));
debug.assert(math.approxEq(f32, c.im, 2.452914, epsilon));
}