/* @Cheng 
 @Jan 11, 2010
 Ninety Parallel Sinusoids With Linearly Increasing Period
 https://ems.andrew.cmu.edu/2010spring/projects/project-0/
 */
 
import processing.pdf.*;
 
float altitude=20.; // altitude of sine wave
float gain = .0038;  // how fashttps://ems.andrew.cmu.edu/2010spring/wp-admin/media-upload.php?post_id=576&TB_iframe=truet the period grow 
float period ; //
float initialPeriod = .55; 
int LeftMargin = 0; // white space 
int upperMargin =5;
 
int x ;
float y ; 
 
smooth();
size (400,410,PDF,"NollSine.pdf");
background (255);
noFill();
strokeWeight(.7);
 
for (int i =0; i<90; i++){
  //point() could induce discrete point;vertext works better 
  beginShape();
  for (x=LeftMargin; x<degrees(width); x++){
    period = initialPeriod+gain* float(x) ; //increase period
    //notice y axis direct downwards; sine wave needs to be reversed
    y = upperMargin + altitude*(-sin(2.*PI*radians(x-LeftMargin)/period)+1.);
    vertex (x,y+i*4);
  }
  endShape();
}