24 lines
620 B
Zig
24 lines
620 B
Zig
const std = @import("../../std.zig");
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const testing = std.testing;
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const math = std.math;
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const cmath = math.complex;
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const Complex = cmath.Complex;
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/// Returns the natural logarithm of z.
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pub fn log(z: anytype) Complex(@TypeOf(z.re, z.im)) {
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const T = @TypeOf(z.re, z.im);
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const r = cmath.abs(z);
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const phi = cmath.arg(z);
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return Complex(T).init(@log(r), phi);
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}
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test log {
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const epsilon = math.floatEps(f32);
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const a = Complex(f32).init(5, 3);
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const c = log(a);
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try testing.expectApproxEqAbs(1.7631803, c.re, epsilon);
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try testing.expectApproxEqAbs(0.5404195, c.im, epsilon);
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}
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