1 files changed, 24 insertions, 0 deletions
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));
+}