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JFreeChart is a class library, written in Java, for generating charts.
Utilising the Java2D APIs, it currently supports bar charts, pie charts,
line charts, XY-plots and time series plots.
/* ===========================================================
* JFreeChart : a free chart library for the Java(tm) platform
* ===========================================================
*
* (C) Copyright 2000-2013, by Object Refinery Limited and Contributors.
*
* Project Info: http://www.jfree.org/jfreechart/index.html
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
* [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
* Other names may be trademarks of their respective owners.]
*
* ---------------------
* HistogramDataset.java
* ---------------------
* (C) Copyright 2003-2013, by Jelai Wang and Contributors.
*
* Original Author: Jelai Wang (jelaiw AT mindspring.com);
* Contributor(s): David Gilbert (for Object Refinery Limited);
* Cameron Hayne;
* Rikard Bj?rklind;
* Thomas A Caswell (patch 2902842);
*
* Changes
* -------
* 06-Jul-2003 : Version 1, contributed by Jelai Wang (DG);
* 07-Jul-2003 : Changed package and added Javadocs (DG);
* 15-Oct-2003 : Updated Javadocs and removed array sorting (JW);
* 09-Jan-2004 : Added fix by "Z." posted in the JFreeChart forum (DG);
* 01-Mar-2004 : Added equals() and clone() methods and implemented
* Serializable. Also added new addSeries() method (DG);
* 06-May-2004 : Now extends AbstractIntervalXYDataset (DG);
* 15-Jul-2004 : Switched getX() with getXValue() and getY() with
* getYValue() (DG);
* 20-May-2005 : Speed up binning - see patch 1026151 contributed by Cameron
* Hayne (DG);
* 08-Jun-2005 : Fixed bug in getSeriesKey() method (DG);
* 22-Nov-2005 : Fixed cast in getSeriesKey() method - see patch 1329287 (DG);
* ------------- JFREECHART 1.0.x ---------------------------------------------
* 03-Aug-2006 : Improved precision of bin boundary calculation (DG);
* 07-Sep-2006 : Fixed bug 1553088 (DG);
* 22-May-2008 : Implemented clone() method override (DG);
* 08-Dec-2009 : Fire change event in addSeries() - see patch 2902842
* contributed by Thomas A Caswell (DG);
* 03-Jul-2013 : Use ParamChecks (DG);
*
*/
package org.jfree.data.statistics;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.jfree.chart.util.ParamChecks;
import org.jfree.data.general.DatasetChangeEvent;
import org.jfree.data.xy.AbstractIntervalXYDataset;
import org.jfree.data.xy.IntervalXYDataset;
import org.jfree.util.ObjectUtilities;
import org.jfree.util.PublicCloneable;
/**
* A dataset that can be used for creating histograms.
*
* @see SimpleHistogramDataset
*/
public class HistogramDataset extends AbstractIntervalXYDataset
implements IntervalXYDataset, Cloneable, PublicCloneable,
Serializable {
/** For serialization. */
private static final long serialVersionUID = -6341668077370231153L;
/** A list of maps. */
private List list;
/** The histogram type. */
private HistogramType type;
/**
* Creates a new (empty) dataset with a default type of
* {@link HistogramType}.FREQUENCY.
*/
public HistogramDataset() {
this.list = new ArrayList();
this.type = HistogramType.FREQUENCY;
}
/**
* Returns the histogram type.
*
* @return The type (never null).
*/
public HistogramType getType() {
return this.type;
}
/**
* Sets the histogram type and sends a {@link DatasetChangeEvent} to all
* registered listeners.
*
* @param type the type (null not permitted).
*/
public void setType(HistogramType type) {
ParamChecks.nullNotPermitted(type, "type");
this.type = type;
fireDatasetChanged();
}
/**
* Adds a series to the dataset, using the specified number of bins,
* and sends a {@link DatasetChangeEvent} to all registered listeners.
*
* @param key the series key (null not permitted).
* @param values the values (null not permitted).
* @param bins the number of bins (must be at least 1).
*/
public void addSeries(Comparable key, double[] values, int bins) {
// defer argument checking...
double minimum = getMinimum(values);
double maximum = getMaximum(values);
addSeries(key, values, bins, minimum, maximum);
}
/**
* Adds a series to the dataset. Any data value less than minimum will be
* assigned to the first bin, and any data value greater than maximum will
* be assigned to the last bin. Values falling on the boundary of
* adjacent bins will be assigned to the higher indexed bin.
*
* @param key the series key (null not permitted).
* @param values the raw observations.
* @param bins the number of bins (must be at least 1).
* @param minimum the lower bound of the bin range.
* @param maximum the upper bound of the bin range.
*/
public void addSeries(Comparable key, double[] values, int bins,
double minimum, double maximum) {
ParamChecks.nullNotPermitted(key, "key");
ParamChecks.nullNotPermitted(values, "values");
if (bins < 1) {
throw new IllegalArgumentException(
"The 'bins' value must be at least 1.");
}
double binWidth = (maximum - minimum) / bins;
double lower = minimum;
double upper;
List binList = new ArrayList(bins);
for (int i = 0; i < bins; i++) {
HistogramBin bin;
// make sure bins[bins.length]'s upper boundary ends at maximum
// to avoid the rounding issue. the bins[0] lower boundary is
// guaranteed start from min
if (i == bins - 1) {
bin = new HistogramBin(lower, maximum);
}
else {
upper = minimum + (i + 1) * binWidth;
bin = new HistogramBin(lower, upper);
lower = upper;
}
binList.add(bin);
}
// fill the bins
for (int i = 0; i < values.length; i++) {
int binIndex = bins - 1;
if (values[i] < maximum) {
double fraction = (values[i] - minimum) / (maximum - minimum);
if (fraction < 0.0) {
fraction = 0.0;
}
binIndex = (int) (fraction * bins);
// rounding could result in binIndex being equal to bins
// which will cause an IndexOutOfBoundsException - see bug
// report 1553088
if (binIndex >= bins) {
binIndex = bins - 1;
}
}
HistogramBin bin = (HistogramBin) binList.get(binIndex);
bin.incrementCount();
}
// generic map for each series
Map map = new HashMap();
map.put("key", key);
map.put("bins", binList);
map.put("values.length", new Integer(values.length));
map.put("bin width", new Double(binWidth));
this.list.add(map);
fireDatasetChanged();
}
/**
* Returns the minimum value in an array of values.
*
* @param values the values (null not permitted and
* zero-length array not permitted).
*
* @return The minimum value.
*/
private double getMinimum(double[] values) {
if (values == null || values.length < 1) {
throw new IllegalArgumentException(
"Null or zero length 'values' argument.");
}
double min = Double.MAX_VALUE;
for (int i = 0; i < values.length; i++) {
if (values[i] < min) {
min = values[i];
}
}
return min;
}
/**
* Returns the maximum value in an array of values.
*
* @param values the values (null not permitted and
* zero-length array not permitted).
*
* @return The maximum value.
*/
private double getMaximum(double[] values) {
if (values == null || values.length < 1) {
throw new IllegalArgumentException(
"Null or zero length 'values' argument.");
}
double max = -Double.MAX_VALUE;
for (int i = 0; i < values.length; i++) {
if (values[i] > max) {
max = values[i];
}
}
return max;
}
/**
* Returns the bins for a series.
*
* @param series the series index (in the range 0 to
* getSeriesCount() - 1).
*
* @return A list of bins.
*
* @throws IndexOutOfBoundsException if series 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.
*/
@Override
public int getSeriesCount() {
return this.list.size();
}
/**
* Returns the key for a series.
*
* @param series the series index (in the range 0 to
* getSeriesCount() - 1).
*
* @return The series key.
*
* @throws IndexOutOfBoundsException if series is outside the
* specified range.
*/
@Override
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 0 to
* getSeriesCount() - 1).
*
* @return The item count.
*
* @throws IndexOutOfBoundsException if series is outside the
* specified range.
*/
@Override
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 0 to
* getSeriesCount() - 1).
* @param item the item index (zero based).
*
* @return The start value.
*
* @throws IndexOutOfBoundsException if series is outside the
* specified range.
*/
@Override
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 0 to
* getSeriesCount() - 1).
* @param item the item index (zero based).
*
* @return The y-value.
*
* @throws IndexOutOfBoundsException if series is outside the
* specified range.
*/
@Override
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 0 to
* getSeriesCount() - 1).
* @param item the item index (zero based).
*
* @return The start value.
*
* @throws IndexOutOfBoundsException if series is outside the
* specified range.
*/
@Override
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 0 to
* getSeriesCount() - 1).
* @param item the item index (zero based).
*
* @return The end value.
*
* @throws IndexOutOfBoundsException if series is outside the
* specified range.
*/
@Override
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 0 to
* getSeriesCount() - 1).
* @param item the item index (zero based).
*
* @return The y-value.
*
* @throws IndexOutOfBoundsException if series is outside the
* specified range.
*/
@Override
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 0 to
* getSeriesCount() - 1).
* @param item the item index (zero based).
*
* @return The Y value.
*
* @throws IndexOutOfBoundsException if series is outside the
* specified range.
*/
@Override
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 (null permitted).
*
* @return A boolean.
*/
@Override
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.
*/
@Override
public Object clone() throws CloneNotSupportedException {
HistogramDataset clone = (HistogramDataset) super.clone();
int seriesCount = getSeriesCount();
clone.list = new java.util.ArrayList(seriesCount);
for (int i = 0; i < seriesCount; i++) {
clone.list.add(new HashMap((Map) this.list.get(i)));
}
return clone;
}
}