From ed36dbbd9c9dc21b2eebae1b31586fea1c6b51c3 Mon Sep 17 00:00:00 2001 From: Andrew Kelley Date: Wed, 25 Sep 2019 23:35:41 -0400 Subject: mv std/ lib/ that's all this commit does. further commits will fix cli flags and such. see #2221 --- lib/std/math/complex/log.zig | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 lib/std/math/complex/log.zig (limited to 'lib/std/math/complex/log.zig') diff --git a/lib/std/math/complex/log.zig b/lib/std/math/complex/log.zig new file mode 100644 index 0000000000..762b4fde9a --- /dev/null +++ b/lib/std/math/complex/log.zig @@ -0,0 +1,24 @@ +const std = @import("../../std.zig"); +const testing = std.testing; +const math = std.math; +const cmath = math.complex; +const Complex = cmath.Complex; + +/// Returns the natural logarithm of z. +pub fn log(z: var) Complex(@typeOf(z.re)) { + const T = @typeOf(z.re); + const r = cmath.abs(z); + const phi = cmath.arg(z); + + return Complex(T).new(math.ln(r), phi); +} + +const epsilon = 0.0001; + +test "complex.clog" { + const a = Complex(f32).new(5, 3); + const c = log(a); + + testing.expect(math.approxEq(f32, c.re, 1.763180, epsilon)); + testing.expect(math.approxEq(f32, c.im, 0.540419, epsilon)); +} -- cgit v1.2.3