sine wave 2

by Julien Etienne

HTML

<canvas id="myCanvas" width="360" height="360" style="border:1px solid #d3d3d3;">

JavaScript

var c = document.getElementById("myCanvas");
var ctx = c.getContext("2d");
var i;
for(i=0; i<360; i+= 20){
 ctx.moveTo(i+5,180);
    ctx.lineTo(i,180);
		
}
ctx.stroke();

var counter = 0, x=0,y=180;


//100 iterations
var increase = 90/180*Math.PI / 9;
for(i=0; i<=360; i+=10){
    
     ctx.moveTo(x,y);
    x = i;
    y =  180 - Math.sin(counter) * 120;
counter += increase;
     
    ctx.lineTo(x,y);
    ctx.stroke();
    //alert( " x : " + x + " y : " + y + " increase : " + counter ) ;

}