Esempio n. 1
0
  protected void paintComponent(Graphics g) {
    super.paintComponent(g);
    Graphics2D g2 = (Graphics2D) g;
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    int w = getWidth();
    int h = getHeight();
    double xScale = (w - 2 * PAD) / (xMax - xMin);
    double yScale = (h - 2 * PAD) / (yMax - yMin);
    if (firstTime) System.out.printf("xScale = %.1f  yScale = %.1f%n", xScale, yScale);
    Point2D.Double origin = new Point2D.Double(); // Axes origin.
    Point2D.Double offset = new Point2D.Double(); // Locate data.
    if (xMax < 0) {
      origin.x = w - PAD;
      offset.x = origin.x - xScale * xMax;
    } else if (xMin < 0) {
      origin.x = PAD - xScale * xMin;
      offset.x = origin.x;
    } else {
      origin.x = PAD;
      offset.x = PAD - xScale * xMin;
    }
    if (yMax < 0) {
      origin.y = h - PAD;
      offset.y = origin.y - yScale * yMax;
    } else if (yMin < 0) {
      origin.y = PAD - yScale * yMin;
      offset.y = origin.y;
    } else {
      origin.y = PAD;
      offset.y = PAD - yScale * yMin;
    }
    if (firstTime) {
      System.out.printf("origin = [%6.1f, %6.1f]%n", origin.x, origin.y);
      System.out.printf("offset = [%6.1f, %6.1f]%n", offset.x, offset.y);
    }

    // Draw abcissa.
    g2.draw(new Line2D.Double(PAD, origin.y, w - PAD, origin.y));
    // Draw ordinate.
    g2.draw(new Line2D.Double(origin.x, PAD, origin.x, h - PAD));
    g2.setPaint(Color.red);
    // Mark origin.
    g2.fill(new Ellipse2D.Double(origin.x - 2, origin.y - 2, 4, 4));

    // Plot data.
    g2.setPaint(Color.blue);
    for (int i = 0; i < x.length; i++) {
      double x1 = offset.x + xScale * x[i];
      double y1 = offset.y + yScale * y[i];
      if (firstTime) System.out.printf("i = %d  x1 = %6.1f  y1 = %.1f%n", i, x1, y1);
      g2.fill(new Ellipse2D.Double(x1 - 2, y1 - 2, 4, 4));
      g2.drawString(String.valueOf(i), (float) x1 + 3, (float) y1 - 3);
    }

    // Draw extreme data values.
    g2.setPaint(Color.black);
    Font font = g2.getFont();
    FontRenderContext frc = g2.getFontRenderContext();
    LineMetrics lm = font.getLineMetrics("0", frc);
    String s = String.format("%.1f", xMin);
    float width = (float) font.getStringBounds(s, frc).getWidth();
    double x = offset.x + xScale * xMin;
    g2.drawString(s, (float) x, (float) origin.y + lm.getAscent());
    s = String.format("%.1f", xMax);
    width = (float) font.getStringBounds(s, frc).getWidth();
    x = offset.x + xScale * xMax;
    g2.drawString(s, (float) x - width, (float) origin.y + lm.getAscent());
    s = String.format("%.1f", yMin);
    width = (float) font.getStringBounds(s, frc).getWidth();
    double y = offset.y + yScale * yMin;
    g2.drawString(s, (float) origin.x + 1, (float) y + lm.getAscent());
    s = String.format("%.1f", yMax);
    width = (float) font.getStringBounds(s, frc).getWidth();
    y = offset.y + yScale * yMax;
    g2.drawString(s, (float) origin.x + 1, (float) y);
    if (firstTime) System.out.println("------------------------------");
    firstTime = false;
  }