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如何在java中画曲线
好问题必须顶，我今天整了一天会画了，你其它要求我也等答案
java 怎么画一个曲线
我做了一个简单的例子，还没有完善好，只是起到一个抛砖引玉的作用，希望你能自己把它补完整。
package test;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.LineBorder;
public class DrawFn extends JFrame{
private JTextField txt_interval;
private JTextField txt_c;
private JTextField txt_b;
private JTextField txt_a;
private drawFnPanel panel = new drawFnPanel();
/**
* @param args
*/
public static void main(String[] args) {
DrawFn frame=new DrawFn();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
public DrawFn() {
super();
getContentPane().setLayout(null);
final JLabel aLabel = new JLabel();
aLabel.setText("a=");
aLabel.setBounds(10, 10, 21, 18);
getContentPane().add(aLabel);
txt_a = new JTextField();
txt_a.setBounds(31, 8, 87, 22);
getContentPane().add(txt_a);
final JLabel bLabel = new JLabel();
bLabel.setText("b=");
bLabel.setBounds(136, 10, 21, 18);
getContentPane().add(bLabel);
txt_b = new JTextField();
txt_b.setBounds(159, 8, 87, 22);
getContentPane().add(txt_b);
final JLabel cLabel = new JLabel();
cLabel.setText("c=");
cLabel.setBounds(267, 10, 32, 18);
getContentPane().add(cLabel);
txt_c = new JTextField();
txt_c.setBounds(290, 8, 87, 22);
getContentPane().add(txt_c);
final JLabel label = new JLabel();
label.setText("步长=");
label.setBounds(398, 10, 47, 18);
getContentPane().add(label);
txt_interval = new JTextField();
txt_interval.setBounds(440, 8, 87, 22);
getContentPane().add(txt_interval);
final JButton button = new JButton();
button.addActionListener(new draw_actionAdapter(this));
button.setText("绘制");
button.setBounds(533, 5, 61, 28);
getContentPane().add(button);
panel.setBorder(new LineBorder(Color.black, 1, false));
panel.setBounds(10, 36, 599, 389);
getContentPane().add(panel);
}
public void paintFn(ActionEvent e){
panel.paintFn(Integer.parseInt(txt_a.getText()), Integer.parseInt(txt_b.getText()), Integer.parseInt(txt_c.getText()), Integer.parseInt(txt_interval.getText()));
}
}
class drawFnPanel extends JPanel{
private int _a=0;
private int _b=0;
private int _c=0;
private float _interval=0.01f;
public void paintFn(int a,int b,int c,int interval){
_a=a;
_b=b;
_c=c;
_interval=interval;
repaint();
}
private double getY(float x){
return _a*x*x+_b*x+_c;
}
public void paintComponent(Graphics g){
Graphics2D g2d=(Graphics2D)g;
if(_a==0 _b==0 _c==0){
return;
}
for(float i=-100f;i100f;i=i+_interval){
g2d.drawRect((int)i, (int)getY(i), 1, 1);
}
}
}
class draw_actionAdapter implements ActionListener{
private DrawFn adapter;
public draw_actionAdapter(DrawFn adapter){
this.adapter=adapter;
}
public void actionPerformed(ActionEvent e) {
adapter.paintFn(e);
}
如何用java做数据曲线图
首先使用JXL读取excel的数据 然后使用JFreeChart把数据转成曲线图 说明: jxl.jar是通过java操作excel表格的工具类库支持Excel 95-2000的所有版本 JFreeChart是JAVA平台上的一个开放的图表绘制类库. 效果图
