How can I make a graph?

Question

I want to give a swing application x and y parameters and it should then draw a graph for me.
x and only be positiv and y can be both positiv and negativ.
I only give x1, y1, x2, y2, x3, y3, etc and it should draw a graph with the given parameter.
is this possible?`
and is there any finished code?

Answer 1

what I already have is this code but here he draws the function x?, but how can I cange it that he only draws the coordinates i give him x1, y1, x2, y2, x3, y3, etc?
// GraphDemo.java
import java.awt.*;
import javax.swing.*;
public class GraphDemo extends JFrame {
GraphDemo()
// super("Resize me!");
this.setTitle("Frame Title");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
getContentPane().add(new GraphPane());
setSize(400,400);
setVisible(true);
public static void main(String[] args) {
new GraphDemo();
class GraphPane extends JPanel
final int margin = 8;
public void paintComponent(Graphics g)
Dimension d = getSize();
Rectangle r = new
Rectangle(margin,margin,d.width-margin*2,d.height-margin*2);
// background color
g.setColor(new Color(255,255,255));
g.fillRect(0,0,d.width,d.height);
// grid color
g.setColor(Color.lightGray);
drawGrid(g,r,16,16);
// line color
g.setColor(Color.blue);
drawFunction(g,r);
private void drawGrid(Graphics g,Rectangle r,int w, int h)
for(int y = 0;y <= h;y++) {
int gy = ntrp(0,h,r.y,r.height,y);
g.drawLine(r.x,gy,r.width,gy);
for(int x = 0;x <= w;x++) {
int gx = ntrp(0,w,r.x,r.width,x);
g.drawLine(gx,r.y,gx,r.height);
private void drawFunction(Graphics g,Rectangle r)
boolean start = true;
double epsilon = .01;
double xa = -3.0;
double xb = 3.0;
int oldx = 0, oldy = 0;
for(double x = xa;x <= xb; x += epsilon)
// just a picturesque
// sample function
double y = Math.exp(-(x*x));
int gx = ntrp(xa,xb,r.x,r.width,x);
int gy = ntrp(0,1,r.height,r.y,y);
if(!start) {
g.drawLine(oldx,oldy,gx,gy);
oldx = gx;
oldy = gy;
start = false;
// interpolation routine
private int ntrp(double xa,double xb,int ya,int yb, double x)
return (int)((x-xa)/(xb-xa) * (yb-ya)) + ya;