Hi guys, I am fairly new to JAVA and currently I am trying to do a couple of pre-set graphs. My first task is to create a graph of y=x^2.

The code below is what i have come up till now. I am sure that i need help in the for loop. I know that i need to do a for loop but im not understanding the process.

import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JApplet;

public class graphic extends JApplet{

	int noOfPoints = 100000;
	int xPoints = 0;
	int yPoints = 0;

       public void paint(Graphics gr)

             Graphics2D g = (Graphics2D)gr;
             g.drawLine(575, 325, 825, 325); //drawing x-axis line
             g.drawLine(700, 200, 700, 450); //drawing y-axis line
             g.drawString("x-axis", 575, 335);//Label for x-axis
             g.drawString("y-axis", 705, 200); //Label for y-axis
             for (int i=-200;i<=500;i++) //Random figures please explian
		         xPoints = (int) (Math.pow(i,2));
			yPoints = (int) (Math.pow(i+1,2));
			g.drawLine(i,i,i,i); //Need help here as well


Thanks & Regards


6 Years
Discussion Span
Last Post by almefab

What do you mean by "Random figures please explian"? If you dont know how a for loop works there are plenty of examples, have a read through some (http://download.oracle.com/javase/tutorial/java/nutsandbolts/for.html)

as for the drawline function, the simplest and best explination is in the java documentation:

drawLine(int x1, int y1, int x2, int y2) -
Draws a line, using the current color, between the points (x1, y1) and (x2, y2) in this graphics context's coordinate system.

Are you drawing the graph in line-segments, or pixel by pixel? Your increment of i++ (ie increasing by 1) implies you are drawing each pixel in which case you dont want to use drawLine (see the post above)

Edited by hanvyj: n/a


Hey guys thanks for the help posted above. Problem was solved by doing graphics.drawLine( pointX, pointY, pointX[i+1], pointY[i+1]

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