import java.awt.*;
import java.applet.*;

public class Fourier extends Applet {

Scrollbar s1,s2,s3,s4,s5,s6,s7,s8;
Label l1,l2,l3,l4,l5,l6,l7,l8;
Panel p1;
double dx,x,y;
double A[]=new double[9];
String whatsis;

public void init(){
setLayout (new BorderLayout());
p1=new Panel();
s1=new Scrollbar(Scrollbar.HORIZONTAL,40,1,0,101);
s2=new Scrollbar(Scrollbar.HORIZONTAL,0,1,0,101);
s3=new Scrollbar(Scrollbar.HORIZONTAL,0,1,0,101);
s4=new Scrollbar(Scrollbar.HORIZONTAL,0,1,0,101);
s5=new Scrollbar(Scrollbar.HORIZONTAL,0,1,0,101);
s6=new Scrollbar(Scrollbar.HORIZONTAL,0,1,0,101);
s7=new Scrollbar(Scrollbar.HORIZONTAL,0,1,0,101);
s8=new Scrollbar(Scrollbar.HORIZONTAL,0,1,0,101);
whatsis="Frequency";
l1=new Label(whatsis +" 1 ");
l2=new Label(whatsis +" 2 ");
l3=new Label(whatsis +" 3 ");
l4=new Label(whatsis +" 4 ");
l5=new Label(whatsis +" 5 ");
l6=new Label(whatsis +" 6 ");
l7=new Label(whatsis +" 7 ");
l8=new Label(whatsis +" 8 ");
p1.setLayout(new GridLayout(8,2,10,10));
p1.add(l1);
p1.add(l5);
p1.add(s1);
p1.add(s5);
p1.add(l2);
p1.add(l6);
p1.add(s2);
p1.add(s6);
p1.add(l3);
p1.add(l7);
p1.add(s3);
p1.add(s7);
p1.add(l4);
p1.add(l8);
p1.add(s4);
p1.add(s8);
add("North",p1);
A[1]=40.0;
A[2]=0.0;
A[3]=0.0;
A[4]=0.0;
A[5]=0.0;
A[6]=0.0;
A[7]=0.0;
A[8]=0.0;
A[0]=0.0;
}

public boolean handleEvent(Event e){
if(e.target instanceof Scrollbar){
int value=((Scrollbar)e.target).getValue();
if(e.target==s1){
A[1]=((double)value)/5.0;l1.setText(whatsis +" 1 "+ Integer.toString(value));}
else if(e.target==s2){
A[2]=((double)value)/5.0;l2.setText(whatsis +" 2 "+ Integer.toString(value));}
else if(e.target==s3){
A[3]=((double)value)/5.0;l3.setText(whatsis +" 3 "+ Integer.toString(value));}
else if(e.target==s4){
A[4]=((double)value)/5.0;l4.setText(whatsis +" 4 "+ Integer.toString(value));}
else if(e.target==s5){
A[5]=((double)value)/5.0;l5.setText(whatsis +" 5 "+ Integer.toString(value));}
else if(e.target==s6){
A[6]=((double)value)/5.0;l6.setText(whatsis +" 6 "+ Integer.toString(value));}
else if(e.target==s7){
A[7]=((double)value)/5.0;l7.setText(whatsis +" 7 "+ Integer.toString(value));}
else if(e.target==s8){
A[8]=((double)value)/5.0;l8.setText(whatsis +" 8 "+ Integer.toString(value));}
repaint();}
return true;}




public void paint(Graphics g){
g.setColor(Color.red);
g.drawRect(30,250,510,300);
g.setColor(Color.black);
g.drawLine(40,400,520,400);
g.drawLine(40,260,40,540);
for(int n=0;n<=1256;n++){
x=(double)n/200.0;
y=0.0;
for(int m=1;m<=8;m++)
y=y+2.0*A[m]*Math.sin(((double)m)*x);
g.setColor(Color.blue);
g.fillOval(40+(int)(75.0*x),400-(int)y,2,2);}
}





}