C# 滤波带通零相位给出错误的结果

我试图实现jsanalytics从以下问题描述的过滤器：

我只是复制了代码并添加了PI，但是在低通滤波器的末尾我得到了一些巨大的数字，零相位看起来不像原始问题的结果

这是我来自jsanalytics的代码

        //signal + noise
        double pi = Math.PI;
        double fs = 1000; //sampling rate
        double fw = 5; //signal frequency
        double n = 5; //number of periods to show
        double A = 10; //signal amplitude
        double N = 2; //noise amplitude
        int size = (int)(n * fs / fw); //sample size

        var t = Enumerable.Range(1, size).Select(p => p * 1 / fs).ToArray();
        var noise = new WhiteGaussianNoiseSource();
        var y = t.Select(p => (A * Math.Sin(2 * pi * fw * p)) + (N * noise.ReadNextSample())).ToArray();

        //filter
        double fc = 10; //cutoff frequency
        var filter = OnlineFirFilter.CreateLowpass(ImpulseResponse.Finite, fs, fc);

        double[] yf1 = filter.ProcessSamples(y); //Lowpass
        double[] yf2 = filter.ProcessSamples(yf1.Reverse().ToArray()); //Lowpass reversed
        double[] yf2r = yf2.Reverse().ToArray(); //Zero-Phase

这是我的代码的结果：

问题：如何获得与jsanalytics匹配的结果