30 lines
986 B
C#
30 lines
986 B
C#
using System;
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namespace FftSharp.Windows
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{
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public class Blackman : Window, IWindow
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{
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private readonly double A = 0.42659071;
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private readonly double B = 0.49656062;
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private readonly double C = 0.07684867;
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public override string Name => "Blackman";
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public override string Description =>
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"These exact values place zeros at the third and fourth sidelobes, " +
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"but result in a discontinuity at the edges and a 6 dB/oct fall-off. " +
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"The truncated coefficients do not null the sidelobes as well, but have an improved 18 dB/oct fall-off.";
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public Blackman() { }
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public Blackman(double a, double b, double c) : this()
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{
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(A, B, C) = (a, b, c);
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}
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protected override double windowValue(int index, int size)
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{
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return A - B * Math.Cos(2 * Math.PI * index / size) + C * Math.Cos(4 * Math.PI * index / size);
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}
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}
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}
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