# Java Algorithms How to - Plot the sine and cosine functions

## Question

We would like to know how to plot the sine and cosine functions.

```import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Polygon;
//from  w  w  w .j  a  v  a 2 s.  co  m
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Main extends JFrame {
public Main() {
setLayout(new BorderLayout());
}

public static void main(String[] args) {
Main frame = new Main();
frame.setSize(400, 300);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}

class DrawSine extends JPanel {
double f(double x) {
return Math.sin(x);
}

double gCos(double y) {
return Math.cos(y);
}

protected void paintComponent(Graphics g) {
super.paintComponent(g);

g.drawLine(10, 100, 380, 100);
g.drawLine(200, 30, 200, 190);

g.drawLine(380, 100, 370, 90);
g.drawLine(380, 100, 370, 110);
g.drawLine(200, 30, 190, 40);
g.drawLine(200, 30, 210, 40);

g.drawString("X", 360, 80);
g.drawString("Y", 220, 40);

Polygon p = new Polygon();
Polygon p2 = new Polygon();

for (int x = -170; x <= 170; x++) {
p.addPoint(x + 200, 100 - (int) (50 * f((x / 100.0) * 2 * Math.PI)));

}

for (int x = -170; x <= 170; x++) {
p2.addPoint(x + 200, 100 - (int) (50 * gCos((x / 100.0) * 2 * Math.PI)));

}

g.setColor(Color.red);
g.drawPolyline(p.xpoints, p.ypoints, p.npoints);
g.drawString("-2\u03c0", 95, 115);
g.drawString("-\u03c0", 147, 115);
g.drawString("\u03c0", 253, 115);
g.drawString("2\u03c0", 305, 115);
g.drawString("0", 200, 115);

g.setColor(Color.blue);
g.drawPolyline(p2.xpoints, p2.ypoints, p2.npoints);

}
}
```