histogramdataset.java

jfreechart不错的教程例子谢谢!

                max = values[i];
            }
        }
        return max;
    }

    /**
     * Returns the bins for a series.
     * 
     * @param series  the series index (in the range <code>0</code> to 
     *     <code>getSeriesCount() - 1</code>).
     * 
     * @return A list of bins.
     * 
     * @throws IndexOutOfBoundsException if <code>series</code> is outside the
     *     specified range.
     */
    List getBins(int series) {
        Map map = (Map) this.list.get(series);
        return (List) map.get("bins"); 
    }

    /**
     * Returns the total number of observations for a series.
     * 
     * @param series  the series index.
     * 
     * @return The total.
     */
    private int getTotal(int series) {
        Map map = (Map) this.list.get(series);
        return ((Integer) map.get("values.length")).intValue(); 
    }

    /**
     * Returns the bin width for a series.
     * 
     * @param series  the series index (zero based).
     * 
     * @return The bin width.
     */
    private double getBinWidth(int series) {
        Map map = (Map) this.list.get(series);
        return ((Double) map.get("bin width")).doubleValue(); 
    }

    /**
     * Returns the number of series in the dataset.
     * 
     * @return The series count.
     */
    public int getSeriesCount() { 
        return this.list.size(); 
    }
    
    /**
     * Returns the key for a series.
     * 
     * @param series  the series index (in the range <code>0</code> to 
     *     <code>getSeriesCount() - 1</code>).
     * 
     * @return The series key.
     * 
     * @throws IndexOutOfBoundsException if <code>series</code> is outside the
     *     specified range.
     */
    public Comparable getSeriesKey(int series) {
        Map map = (Map) this.list.get(series);
        return (Comparable) map.get("key"); 
    }

    /**
     * Returns the number of data items for a series.
     * 
     * @param series  the series index (in the range <code>0</code> to 
     *     <code>getSeriesCount() - 1</code>).
     * 
     * @return The item count.
     * 
     * @throws IndexOutOfBoundsException if <code>series</code> is outside the
     *     specified range.
     */
    public int getItemCount(int series) {
        return getBins(series).size(); 
    }

    /**
     * Returns the X value for a bin.  This value won't be used for plotting 
     * histograms, since the renderer will ignore it.  But other renderers can 
     * use it (for example, you could use the dataset to create a line
     * chart).
     * 
     * @param series  the series index (in the range <code>0</code> to 
     *     <code>getSeriesCount() - 1</code>).
     * @param item  the item index (zero based).
     * 
     * @return The start value.
     * 
     * @throws IndexOutOfBoundsException if <code>series</code> is outside the
     *     specified range.
     */
    public Number getX(int series, int item) {
        List bins = getBins(series);
        HistogramBin bin = (HistogramBin) bins.get(item);
        double x = (bin.getStartBoundary() + bin.getEndBoundary()) / 2.;
        return new Double(x);
    }

    /**
     * Returns the y-value for a bin (calculated to take into account the 
     * histogram type).
     * 
     * @param series  the series index (in the range <code>0</code> to 
     *     <code>getSeriesCount() - 1</code>).
     * @param item  the item index (zero based).
     * 
     * @return The y-value.
     * 
     * @throws IndexOutOfBoundsException if <code>series</code> is outside the
     *     specified range.
     */
    public Number getY(int series, int item) {
        List bins = getBins(series);
        HistogramBin bin = (HistogramBin) bins.get(item);
        double total = getTotal(series);
        double binWidth = getBinWidth(series);

        if (this.type == HistogramType.FREQUENCY) {
            return new Double(bin.getCount());
        }
        else if (this.type == HistogramType.RELATIVE_FREQUENCY) {
            return new Double(bin.getCount() / total);
        }
        else if (this.type == HistogramType.SCALE_AREA_TO_1) {
            return new Double(bin.getCount() / (binWidth * total));
        }
        else { // pretty sure this shouldn't ever happen
            throw new IllegalStateException();
        }
    }

    /**
     * Returns the start value for a bin.
     * 
     * @param series  the series index (in the range <code>0</code> to 
     *     <code>getSeriesCount() - 1</code>).
     * @param item  the item index (zero based).
     * 
     * @return The start value.
     * 
     * @throws IndexOutOfBoundsException if <code>series</code> is outside the
     *     specified range.
     */
    public Number getStartX(int series, int item) {
        List bins = getBins(series);
        HistogramBin bin = (HistogramBin) bins.get(item);
        return new Double(bin.getStartBoundary());
    }

    /**
     * Returns the end value for a bin.
     * 
     * @param series  the series index (in the range <code>0</code> to 
     *     <code>getSeriesCount() - 1</code>).
     * @param item  the item index (zero based).
     * 
     * @return The end value.
     * 
     * @throws IndexOutOfBoundsException if <code>series</code> is outside the
     *     specified range.
     */
    public Number getEndX(int series, int item) {
        List bins = getBins(series);
        HistogramBin bin = (HistogramBin) bins.get(item);
        return new Double(bin.getEndBoundary());
    }

    /**
     * Returns the start y-value for a bin (which is the same as the y-value, 
     * this method exists only to support the general form of the 
     * {@link IntervalXYDataset} interface).
     * 
     * @param series  the series index (in the range <code>0</code> to 
     *     <code>getSeriesCount() - 1</code>).
     * @param item  the item index (zero based).
     * 
     * @return The y-value.
     * 
     * @throws IndexOutOfBoundsException if <code>series</code> is outside the
     *     specified range.
     */
    public Number getStartY(int series, int item) {
        return getY(series, item);
    }

    /**
     * Returns the end y-value for a bin (which is the same as the y-value, 
     * this method exists only to support the general form of the 
     * {@link IntervalXYDataset} interface).
     * 
     * @param series  the series index (in the range <code>0</code> to 
     *     <code>getSeriesCount() - 1</code>).
     * @param item  the item index (zero based).
     * 
     * @return The Y value.
     * 
     * @throws IndexOutOfBoundsException if <code>series</code> is outside the
     *     specified range.
     */    
    public Number getEndY(int series, int item) {
        return getY(series, item);
    }

    /**
     * Tests this dataset for equality with an arbitrary object.
     * 
     * @param obj  the object to test against (<code>null</code> permitted).
     * 
     * @return A boolean.
     */
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;   
        }
        if (!(obj instanceof HistogramDataset)) {
            return false;
        }
        HistogramDataset that = (HistogramDataset) obj;
        if (!ObjectUtilities.equal(this.type, that.type)) {
            return false;
        }
        if (!ObjectUtilities.equal(this.list, that.list)) {
            return false;
        }
        return true;   
    }

    /**
     * Returns a clone of the dataset.
     * 
     * @return A clone of the dataset.
     * 
     * @throws CloneNotSupportedException if the object cannot be cloned.
     */
    public Object clone() throws CloneNotSupportedException {
        return super.clone();   
    }

}