Question

编写程序，画出函数f(x)=x*x的图像用java如何写？

Answer 1

import java.awt.*;
import java.awt.geom.*;
import javax.swing.*;

public class hanshu
{
public static void main(String[] args)
{
DrawFrame frame=new DrawFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}

}
class DrawFrame extends JFrame
{
public DrawFrame()
{
setTitle("DrawTest");
setSize(400,400);

// add panel to frame

DrawPanel panel = new DrawPanel();
add(panel);
}
}

class DrawPanel extends JPanel
{
public void paintComponent(Graphics g)
{
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;

int centerx=0;
int centery=0;
int minx=-150;
int maxx=150;
int miny=-150;
int maxy=150;

g2.translate(200,200);
g2.draw(new Line2D.Double(minx,centery,maxx,centery));
g2.draw(new Line2D.Double(maxx,centery,maxx-1,centery-1));
g2.draw(new Line2D.Double(maxx,centery,maxx-1,centery+1));
g2.drawString("X",151,0);
g2.draw(new Line2D.Double(centerx,miny,centerx,maxy));
g2.draw(new Line2D.Double(centerx,miny,centerx-1,miny+1));
g2.draw(new Line2D.Double(centerx,miny,centerx+1,miny+1));
g2.drawString("Y",-7,-145);
g2.drawString("Y=X*X",5,150);

int[] arrayy=new int[200];
int[] arrayx=new int[200];
arrayx[0]=-100;
for (int i=0;i<199;i++)
{
arrayx[i+1]=arrayx[0]+i;
}
for (int i=0;i<200;i++)
{
arrayy[i]=-Function(arrayx[i])/10;
}

g2.drawPolyline(arrayx,arrayy,200);

}
public static int Function(int x)
{
return x*x;
}
}

追问

你的方法我研究一下，我写的和你的有些差别，还是谢谢