C# 傅丽叶变换算法,高手请时!!!

[xinyun80]

主要是用来绘制声音波形,快速傅丽叶就行，不需要太复杂

[xhueducls]

没有现成的控件吗？傅里叶好像高数里的东东

[cppfaq]

private Complex[] FFT(Complex[] input,bool invert)
{
    if (input.Length == 1)
    {
        return new Complex[] { input[0] };
    }
    int length = input.Length;
    int half = length / 2;
    Complex[] result = new Complex[length];
    double fac = -2.0 * Math.PI / length;
    if (invert)
    {
        fac = -fac;
    }

    Complex[] evens = new Complex[half];
    for (int i = 0; i < half; i++)
    {
        evens[i] = input[2 * i];
    }
    Complex[] evenResult = FFT(evens,invert);

    Complex[] odds = evens;
    for (int i = 0; i < half; i++)
    {
        odds[i] = input[2 * i + 1];
    }
    Complex[] oddResult = FFT(odds,invert);

    for (int k = 0; k < half; k++)
    {
        double fack = fac * k;
        Complex oddPart = oddResult[k] * new Complex(Math.Cos(fack), Math.Sin(fack));
        result[k] = evenResult[k] + oddPart;
        result[k + half] = evenResult[k] - oddPart;
    }

    return result;
}

[我姓区不姓区]

http://www.sdss.jhu.edu/~tamas/bytes/fftwcsharp.html

[MikeCheers]

标记一下

[civanx]

可以搜出一堆来，呵呵

快速傅立叶变换FFT源码

[xinyun80]

Complex[]怎么理解?
FFT(Complex[] input,bool invert) 参数 invert起什么作用?

[Terry717]

帮顶

[dw_cbhb]

帮顶

[homejiji]

关注，嘿嘿

[浪子-无悔]

支持。。。

[啊兵]

楼主我顶你上去

[jiaxintaiyang]

Mark，日后再看。