interregresspanel.java

一个一元曲线多项式数值演示例子

package numbercruncher.pointutils;

import java.awt.*;
import java.awt.event.*;

/**
 * The base panel for the interpolation and regression panels.
 */
public abstract class InterRegressPanel
    extends UserPointPanel {
  /** true if OK to plot function */
  protected boolean plotOK = false;

  /**
   * Constructor.
   * @param maxPoints the maximum number of data points
   * @param actionButton1Label the label for action button 1
   * @param actionButton2Label the label for action button 2
   */
  protected InterRegressPanel(int maxPoints,
                              String actionButton1Label,
                              String actionButton2Label) {
    this(maxPoints, actionButton1Label, actionButton2Label, false);
  }

  /**
   * Constructor.
   * @param maxPoints the maximum number of data points
   * @param actionButton1Label the label for action button 1
   * @param actionButton2Label the label for action button 2
   * @param enableDegree true to enable the degree choice, false to disable
   */
  protected InterRegressPanel(int maxPoints,
                              String actionButton1Label,
                              String actionButton2Label,
                              boolean showDegree) {
    super(maxPoints, "# points:", actionButton1Label, actionButton2Label);

    Label degreeLabel = new Label();
    Choice degreeChoice = new Choice();

    // Control panel.
    controlPanel.setLayout(new GridLayout(0, 3, 5, 2));
    controlPanel.add(actionButton1);
    controlPanel.add(nLabel);
    controlPanel.add(nText);
    controlPanel.add(actionButton2);

    // Degree control.
    if (showDegree) {
      Font labelFont = getLabelFont();
      Font textFont = getTextFont();

      degreeLabel.setFont(labelFont);
      degreeLabel.setAlignment(Label.RIGHT);
      degreeLabel.setText("Degree:");

      for (int i = 1; i <= 9; ++i) {
        degreeChoice.add(Integer.toString(i));

      }
      controlPanel.add(degreeLabel);
      controlPanel.add(degreeChoice);
    }
    addDemoControls(controlPanel);

    actionButton1.setEnabled(false);

    // Degree choice handler.
    degreeChoice.addItemListener(new ItemListener() {
      public void itemStateChanged(ItemEvent ev) {
        Choice choice = (Choice) ev.getItemSelectable();
        int degree = choice.getSelectedIndex() + 1;
        degreeChanged(degree);
        draw();
      }
    });
  }

  /**
   * Notify that the degree has changed.  (Do nothing here.)
   * @param degree the new degree
   */
  protected void degreeChanged(int degree) {}

  /**
   * Return whether or not it's OK to plot the function.
   * @return true if OK, otherwise false
   */
  protected boolean plotOK() {
    return plotOK;
  }
}