function drawRadarNet(ctx,centerx,centery,ray,rayNumber){
	for(i=0;i<rayNumber;i++){
      		drawRay(ctx,centerx,centery,Math.PI/2+2*Math.PI/rayNumber*i,ray);
      	}
}
      			
function drawRay(ctx,centerx,centery,angle,ray){
	ctx.moveTo(centerx,centery);
	var xdelta=Math.cos(angle)*ray;
	var ydelta=Math.sin(angle)*ray;
	ctx.lineTo(centerx+xdelta,centery-ydelta);
	ctx.stroke();
}
      			
function drawColoredNet(ctx,centerx,centery,ray,punti,color){
      	ctx.beginPath();
        ctx.strokeStyle = color;
	drawNet(ctx,centerx,centery,ray,punti);
}
      
function drawNet(ctx,centerx,centery,ray,punti){
	var xdelta=Math.cos(Math.PI/2)*ray*punti[0]/100;
      	var ydelta=Math.sin(Math.PI/2)*ray*punti[0]/100;      	
      	ctx.moveTo(centerx+xdelta,centery-ydelta);
      	for(i=1;i<punti.length;i++){
      		xdelta=Math.cos(Math.PI/2+2*Math.PI/punti.length*i)*ray*punti[i]/100;
      		ydelta=Math.sin(Math.PI/2+2*Math.PI/punti.length*i)*ray*punti[i]/100;
      		ctx.lineTo(centerx+xdelta,centery-ydelta);	
      	}
      	ctx.closePath();
      	ctx.stroke();
}