float[] signal = {168.02423,167.11852,167.50813,166.8597,166.05814,165.11226,164.18024,162.52278,159.26706,154.01059,151.02512,145.88942,139.96555,131.64963,128.41841,125.55873,123.26397,121.80526,120.997765,120.13878,120.15161,120.45633,121.23436,120.788994,120.17174,119.775856,119.009384,117.477,115.0316,108.588875,100.850945,88.417404,82.39221,74.47572,68.39083,60.352554,57.09356,54.930645,54.195927,53.56418,53.094868,53.119434,53.129646,53.692352,53.817867,54.48929,55.07399,56.200096,56.464325,56.61977,56.26392,55.87918,55.708,56.005222,56.370075,57.943306,60.338276,66.09525,71.971245,83.3894,93.25841,106.6345,111.20811,114.71198,117.44606,120.572174,122.55059,125.76803,130.27737,136.78697,139.3824,141.46649,143.04817,146.876,153.58531,163.69055,167.01625,169.79066,171.79346,172.96455,174.65863,174.15462,169.83751,160.82489,157.3805,154.58945,152.88863,151.37778,149.86177,148.10445,146.99503,143.16574,136.07457,123.7554,116.98741,107.79893,101.15501,92.90702,89.435356,86.62778,84.60331,82.44227,81.345985,80.086426,78.7316,75.1582,70.30843,62.90986,60.226223,57.940796,56.880646,55.95489,55.675377,55.12072,54.582558,53.560856,53.353596,53.047993,52.981926,52.87674,53.188942,53.541054,53.332302,52.96336,52.367634,53.034874,54.12153,54.88389,57.317207,60.54665,66.118195,70.391785,77.9589,84.03312,93.41969,99.085686,105.99711,109.171776,112.26317,114.13363,116.024254,117.41363,118.9697,120.61764,121.154816,121.67257,121.55961,121.32448,120.59877,120.989365,121.22733,121.907104,122.72483,123.732155,124.994804,126.84889,129.00806,134.3398,141.73413,152.50774,156.32497,159.0031,160.628,161.92178,163.19771,164.65904,166.22505,167.14778,167.68938,168.30038,168.64857,169.15517,168.63728,168.94241};

int sl = signal.length;

void setup(){

  size(400,400);

  noFill();

  smooth();

  

  float[] sorted = new float[sl];

  arrayCopy(signal,sorted);

  Arrays.sort(sorted);

  float min = sorted[0];

  float max = sorted[sl-1];

  

  background(255);

  boolean wasPlus = true,isPlus = false;

  for(int i = 0 ; i < sl; i++){

    //plotting

    float x = map(i,0,sl,1,width-1);

    float y = map(signal[i],min,max,height,0);

    stroke(0);

    line(x,height,x,y);

    //zerox

    float c = signal[i];//current

    float p = signal[i < 1 ? sl-1 : i-1];//previous

    isPlus = (c-p) > 0;

    if(isPlus != wasPlus) {

      stroke(192,0,0);

      ellipse(x,y,5,5);

      wasPlus = isPlus;

    }

  }

}