[java] implementare un istogramma

[salim]

Ciao a tutti!
ho un problema per creare un istogramma in java, partendo da 0. Qualcuno sa come potrei iniziare a fare questo grafico o a darmi un input?
Grazie!

[ally]

...qualcosa di precotto?...jfreechart?...

[:.Blizzard.:]

Io ne feci a suo tempo uno sempliciotto. Ti basta il drawRect e variare l'altezza in proporzione ai valori che devi riportare.

[salim]

jFreeChart l'ho trovato su internet, ma solo la versione demo che non riporta il codice sorgente dei grafici.
Mentre con drawRect lo devo fare tutto manuale. Se non trovo la versione integrale di jFreeChart lo faccio manuale. Cmq grazie per avere risposto!

[ally]

...uno spunto da java2s...

import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GradientPaint;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.Stroke;
import java.awt.event.ComponentEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import java.awt.geom.AffineTransform;
import java.awt.geom.Arc2D;
import java.awt.geom.GeneralPath;
import java.awt.geom.Rectangle2D;

import javax.swing.ImageIcon;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

public class Charts2D extends JFrame {

  public Charts2D() {
    super("2D Charts");
    setSize(720, 280);
    getContentPane().setLayout(new GridLayout(1, 3, 10, 0));
    getContentPane().setBackground(Color.white);

    int[] xData = new int[8];
    int[] yData = new int[8];
    for (int i = 0; i < xData.length; i++) {
      xData[i] = i;
      yData[i] = (int) (Math.random() * 100);
      if (i > 0)
        yData[i] = (yData[i - 1] + yData[i]) / 2;
    }

    JChart2D chart = new JChart2D(JChart2D.LineChart, xData.length, xData, yData,
        "Line Chart");
    chart.setStroke(new BasicStroke(5f, BasicStroke.CAP_ROUND,
        BasicStroke.JOIN_MITER));
    chart.setLineColor(new Color(0, 28, 28));
    getContentPane().add(chart);

    chart = new JChart2D(JChart2D.ColumnChart, xData.length, xData, yData,
        "Column Chart");
    GradientPaint gp = new GradientPaint(0, 100, Color.white, 0, 300,
        Color.blue, true);
    chart.setGradient(gp);
    chart.setEffectIndex(JChart2D.Gradientffect);
    chart.setDrawShadow(true);
    getContentPane().add(chart);

    chart = new JChart2D(JChart2D.PieChart, xData.length, xData, yData,
        "Pie Chart");
    ImageIcon icon = new ImageIcon("largeJava2slogo.GIF");
    chart.setForegroundImage(icon.getImage());
    chart.setEffectIndex(JChart2D.ImageEffect);
    chart.setDrawShadow(true);
    getContentPane().add(chart);

    WindowListener wndCloser = new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    };
    addWindowListener(wndCloser);

    setVisible(true);
  }

  public static void main(String argv[]) {
    new Charts2D();
  }

}

class JChart2D extends JPanel {
  public static final int LineChart = 0;

  public static final int ColumnChart = 1;

  public static final int PieChart = 2;

  public static final int PLainEffect = 0;

  public static final int Gradientffect = 1;

  public static final int ImageEffect = 2;

  protected int m_chartType = LineChart;

  protected JLabel titleLabel;

  protected ChartPanel chartPanel;

  protected int dataLength;

  protected int[] xData;

  protected int[] yData;

  protected int xMin;

  protected int xMax;

  protected int yMin;

  protected int yMax;

  protected double[] pieData;

  protected int m_effectIndex = PLainEffect;

  protected Stroke stroke;

  protected GradientPaint gradient;

  protected Image foregroundImage;

  protected Color lineColor = Color.black;

  protected Color columnColor = Color.blue;

  protected int columnWidth = 12;

  protected boolean drawShadow = false;

  public JChart2D(int type, int nData, int[] yData, String text) {
    this(type, nData, null, yData, text);
  }

  public JChart2D(int type, int nData, int[] xD, int[] yD, String text) {
    super(new BorderLayout());
    setBackground(Color.white);
    titleLabel = new JLabel(text, JLabel.CENTER);
    add(titleLabel, BorderLayout.NORTH);

    m_chartType = type;

    if (xData == null) {
      xData = new int[nData];
      for (int k = 0; k < nData; k++)
        xData[k] = k;
    }
    if (yD == null)
      throw new IllegalArgumentException("yData can't be null");
    if (nData > yD.length)
      throw new IllegalArgumentException("Insufficient yData length");
    if (nData > xD.length)
      throw new IllegalArgumentException("Insufficient xData length");
    dataLength = nData;
    xData = xD;
    yData = yD;

    xMin = xMax = 0; // To include 0 into the interval
    yMin = yMax = 0;
    for (int k = 0; k < dataLength; k++) {
      xMin = Math.min(xMin, xData[k]);
      xMax = Math.max(xMax, xData[k]);
      yMin = Math.min(yMin, yData[k]);
      yMax = Math.max(yMax, yData[k]);
    }
    if (xMin == xMax)
      xMax++;
    if (yMin == yMax)
      yMax++;

    if (m_chartType == PieChart) {
      double sum = 0;
      for (int k = 0; k < dataLength; k++) {
        yData[k] = Math.max(yData[k], 0);
        sum += yData[k];
      }
      pieData = new double[dataLength];
      for (int k = 0; k < dataLength; k++)
        pieData[k] = yData[k] * 360.0 / sum;
    }

    chartPanel = new ChartPanel();
    add(chartPanel, BorderLayout.CENTER);
  }

  public void setEffectIndex(int effectIndex) {
    m_effectIndex = effectIndex;
    repaint();
  }

  public int getEffectIndex() {
    return m_effectIndex;
  }

  public void setStroke(Stroke s) {
    stroke = s;
    chartPanel.repaint();
  }

  public void setForegroundImage(Image img) {
    foregroundImage = img;
    repaint();
  }

  public Image getForegroundImage() {
    return foregroundImage;
  }

  public Stroke getStroke() {
    return stroke;
  }

  public void setGradient(GradientPaint g) {
    gradient = g;
    repaint();
  }

  public GradientPaint getGradient() {
    return gradient;
  }

  public void setColumnWidth(int c) {
    columnWidth = c;
    chartPanel.calcDimensions();
    chartPanel.repaint();
  }

  public int setColumnWidth() {
    return columnWidth;
  }

  public void setColumnColor(Color c) {
    columnColor = c;
    chartPanel.repaint();
  }

  public Color getColumnColor() {
    return columnColor;
  }

  public void setLineColor(Color c) {
    lineColor = c;
    chartPanel.repaint();
  }

  public Color getLineColor() {
    return lineColor;
  }

  public void setDrawShadow(boolean d) {
    drawShadow = d;
    chartPanel.repaint();
  }

  public boolean getDrawShadow() {
    return drawShadow;
  }

  class ChartPanel extends JComponent {
    int xMargin = 5;

    int yMargin = 5;

    int pieGap = 10;

    int m_x;

    int m_y;

    int m_w;

    int m_h;

    ChartPanel() {
      enableEvents(ComponentEvent.COMPONENT_RESIZED);
    }

    protected void processComponentEvent(ComponentEvent e) {
      calcDimensions();
    }

    public void calcDimensions() {
      Dimension d = getSize();
      m_x = xMargin;
      m_y = yMargin;
      m_w = d.width - 2 * xMargin;
      m_h = d.height - 2 * yMargin;
      if (m_chartType == ColumnChart) {
        m_x += columnWidth / 2;
        m_w -= columnWidth;
      }
    }

    public int xChartToScreen(int x) {
      return m_x + (x - xMin) * m_w / (xMax - xMin);
    }

    public int yChartToScreen(int y) {
      return m_y + (yMax - y) * m_h / (yMax - yMin);
    }

    public void paintComponent(Graphics g) {
      int x0 = 0;
      int y0 = 0;
      if (m_chartType != PieChart) {
        g.setColor(Color.black);
        x0 = xChartToScreen(0);
        g.drawLine(x0, m_y, x0, m_y + m_h);
        y0 = yChartToScreen(0);
        g.drawLine(m_x, y0, m_x + m_w, y0);
      }

      Graphics2D g2 = (Graphics2D) g;
      g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
          RenderingHints.VALUE_ANTIALIAS_ON);
      g2.setRenderingHint(RenderingHints.KEY_RENDERING,
          RenderingHints.VALUE_RENDER_QUALITY);

      if (stroke != null)
        g2.setStroke(stroke);

      GeneralPath path = new GeneralPath();
      switch (m_chartType) {
      case LineChart:
        g2.setColor(lineColor);
        path.moveTo(xChartToScreen(xData[0]),
            yChartToScreen(yData[0]));
        for (int k = 1; k < dataLength; k++)
          path.lineTo(xChartToScreen(xData[k]),
              yChartToScreen(yData[k]));
        g2.draw(path);
        break;

      case ColumnChart:
        for (int k = 0; k < dataLength; k++) {
          xMax++;
          int x = xChartToScreen(xData[k]);
          int w = columnWidth;
          int y1 = yChartToScreen(yData[k]);
          int y = Math.min(y0, y1);
          int h = Math.abs(y1 - y0);
          Shape rc = new Rectangle2D.Double(x, y, w, h);
          path.append(rc, false);
          xMax--;
        }

        if (drawShadow) {
          AffineTransform s0 = new AffineTransform(1.0, 0.0, 0.0,
              -1.0, x0, y0);
          s0.concatenate(AffineTransform.getScaleInstance(1.0, 0.5));
          s0.concatenate(AffineTransform.getShearInstance(0.5, 0.0));
          s0.concatenate(new AffineTransform(1.0, 0.0, 0.0, -1.0,
              -x0, y0));
          g2.setColor(Color.gray);
          Shape shadow = s0.createTransformedShape(path);
          g2.fill(shadow);
        }

        if (m_effectIndex == Gradientffect && gradient != null) {
          g2.setPaint(gradient);
          g2.fill(path);
        } else if (m_effectIndex == ImageEffect
            && foregroundImage != null)
          fillByImage(g2, path, 0);
        else {
          g2.setColor(columnColor);
          g2.fill(path);
        }
        g2.setColor(lineColor);
        g2.draw(path);
        break;

      case PieChart:
        double start = 0.0;
        double finish = 0.0;
        int ww = m_w - 2 * pieGap;
        int hh = m_h - 2 * pieGap;
        if (drawShadow) {
          ww -= pieGap;
          hh -= pieGap;
        }

        for (int i = 0; i < dataLength; i++) {
          finish = start + pieData[i];
          double f1 = Math.min(90 - start, 90 - finish);
          double f2 = Math.max(90 - start, 90 - finish);
          Shape shp = new Arc2D.Double(m_x, m_y, ww, hh, f1, f2 - f1,
              Arc2D.PIE);
          double f = (f1 + f2) / 2 * Math.PI / 180;
          AffineTransform s1 = AffineTransform.getTranslateInstance(
              pieGap * Math.cos(f), -pieGap * Math.sin(f));
          s1.translate(pieGap, pieGap);
          Shape piece = s1.createTransformedShape(shp);
          path.append(piece, false);
          start = finish;
        }

        if (drawShadow) {
          AffineTransform s0 = AffineTransform.getTranslateInstance(
              pieGap, pieGap);
          g2.setColor(Color.gray);
          Shape shadow = s0.createTransformedShape(path);
          g2.fill(shadow);
        }

        if (m_effectIndex == Gradientffect && gradient != null) {
          g2.setPaint(gradient);
          g2.fill(path);
        } else if (m_effectIndex == ImageEffect
            && foregroundImage != null)
          fillByImage(g2, path, 0);
        else {
          g2.setColor(columnColor);
          g2.fill(path);
        }

        g2.setColor(lineColor);
        g2.draw(path);
        break;
      }
    }

    protected void fillByImage(Graphics2D g2, Shape shape, int xOffset) {
      if (foregroundImage == null)
        return;
      int wImg = foregroundImage.getWidth(this);
      int hImg = foregroundImage.getHeight(this);
      if (wImg <= 0 || hImg <= 0)
        return;
      g2.setClip(shape);
      Rectangle bounds = shape.getBounds();
      for (int i = bounds.x + xOffset; i < bounds.x + bounds.width; i += wImg)
        for (int j = bounds.y; j < bounds.y + bounds.height; j += hImg)
          g2.drawImage(foregroundImage, i, j, this);
    }
  }
}

... http://www.java2s.com/Code/Java/2D-G...ndpiechart.htm ...