processing模拟三角级数合成方波过程

代码

   1: int radius = 2;

   2: int[] accumys;

   3: int times = 0;

   4:  

   5: float scale = 1;

   6: int origin = 400;

   7:  

   8: float factor = 1;

   9:  

  10: public void setup() {

  11:   size(displayWidth, displayHeight);

  12:   background(0);

  13:   frameRate(2);

  14:  

  15:   accumys = new int[displayWidth];

  16:   

  17:   for(int i=0;i<displayWidth;i++)

  18:   {

  19:       accumys[i] = 0;

  20:   }

  21:   

  22:   scale = 1;

  23:   origin = displayHeight / 2;

  24:   

  25:   factor = (PI * 3/ displayWidth );

  26: }

  27:  

  28: public void draw() {  

  29:  

  30:     fill(0,0,0,50);

  31:     rect(-1,-1,displayWidth + 1, displayHeight+1);

  32:     

  33:     float k = ++times;

  34:     int last_y = 0;

  35:     for (int i=0;i<displayWidth;i++)

  36:     {

  37:         float t = i;

  38:         float up = sin((2 * k - 1) * factor * t);

  39:         float down = (2 * k - 1) * factor;

  40:         

  41:         accumys[i] += (int) ((float)4 * up / (PI * down));

  42:         

  43:         if (i >= 1)

  44:         {

  45:             colorMode(HSB, 255);

  46:             stroke(90, 255, 255);

  47:             line(i-1, last_y * scale + origin, i, accumys[i] * scale + origin);

  48:             line(i, last_y * scale + origin, i+1, accumys[i] * scale + origin);

  49:         }

  50:         

  51:         last_y = accumys[i];

  52:     }

  53:     

  54: }

截图