001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2011, by Object Refinery Limited and Contributors.
006     *
007     * Project Info:  http://www.jfree.org/jfreechart/index.html
008     *
009     * This library is free software; you can redistribute it and/or modify it
010     * under the terms of the GNU Lesser General Public License as published by
011     * the Free Software Foundation; either version 2.1 of the License, or
012     * (at your option) any later version.
013     *
014     * This library is distributed in the hope that it will be useful, but
015     * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016     * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017     * License for more details.
018     *
019     * You should have received a copy of the GNU Lesser General Public
020     * License along with this library; if not, write to the Free Software
021     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
022     * USA.
023     *
024     * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
025     * Other names may be trademarks of their respective owners.]
026     *
027     * -------------
028     * XYSeries.java
029     * -------------
030     * (C) Copyright 2001-2011, Object Refinery Limited and Contributors.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   Aaron Metzger;
034     *                   Jonathan Gabbai;
035     *                   Richard Atkinson;
036     *                   Michel Santos;
037     *                   Ted Schwartz (fix for bug 1955483);
038     *
039     * Changes
040     * -------
041     * 15-Nov-2001 : Version 1 (DG);
042     * 03-Apr-2002 : Added an add(double, double) method (DG);
043     * 29-Apr-2002 : Added a clear() method (ARM);
044     * 06-Jun-2002 : Updated Javadoc comments (DG);
045     * 29-Aug-2002 : Modified to give user control over whether or not duplicate
046     *               x-values are allowed (DG);
047     * 07-Oct-2002 : Fixed errors reported by Checkstyle (DG);
048     * 11-Nov-2002 : Added maximum item count, code contributed by Jonathan
049     *               Gabbai (DG);
050     * 26-Mar-2003 : Implemented Serializable (DG);
051     * 04-Aug-2003 : Added getItems() method (DG);
052     * 15-Aug-2003 : Changed 'data' from private to protected, added new add()
053     *               methods with a 'notify' argument (DG);
054     * 22-Sep-2003 : Added getAllowDuplicateXValues() method (RA);
055     * 29-Jan-2004 : Added autoSort attribute, based on a contribution by
056     *               Michel Santos - see patch 886740 (DG);
057     * 03-Feb-2004 : Added indexOf() method (DG);
058     * 16-Feb-2004 : Added remove() method (DG);
059     * 18-Aug-2004 : Moved from org.jfree.data --> org.jfree.data.xy (DG);
060     * 21-Feb-2005 : Added update(Number, Number) and addOrUpdate(Number, Number)
061     *               methods (DG);
062     * 03-May-2005 : Added a new constructor, fixed the setMaximumItemCount()
063     *               method to remove items (and notify listeners) if necessary,
064     *               fixed the add() and addOrUpdate() methods to handle unsorted
065     *               series (DG);
066     * ------------- JFreeChart 1.0.x ---------------------------------------------
067     * 11-Jan-2005 : Renamed update(int, Number) --> updateByIndex() (DG);
068     * 15-Jan-2007 : Added toArray() method (DG);
069     * 31-Oct-2007 : Implemented faster hashCode() (DG);
070     * 22-Nov-2007 : Reimplemented clone() (DG);
071     * 01-May-2008 : Fixed bug 1955483 in addOrUpdate() method, thanks to
072     *               Ted Schwartz (DG);
073     * 24-Nov-2008 : Further fix for 1955483 (DG);
074     * 06-Mar-2009 : Added minX, maxX, minY and maxY fields (DG);
075     * 10-Jun-2009 : Make clones to isolate XYDataItem instances used
076     *               for data storage (DG);
077     * 
078     */
079    
080    package org.jfree.data.xy;
081    
082    import java.io.Serializable;
083    import java.util.Collections;
084    import java.util.Iterator;
085    import java.util.List;
086    
087    import org.jfree.data.general.Series;
088    import org.jfree.data.general.SeriesChangeEvent;
089    import org.jfree.data.general.SeriesException;
090    import org.jfree.util.ObjectUtilities;
091    
092    /**
093     * Represents a sequence of zero or more data items in the form (x, y).  By
094     * default, items in the series will be sorted into ascending order by x-value,
095     * and duplicate x-values are permitted.  Both the sorting and duplicate
096     * defaults can be changed in the constructor.  Y-values can be
097     * <code>null</code> to represent missing values.
098     */
099    public class XYSeries extends Series implements Cloneable, Serializable {
100    
101        /** For serialization. */
102        static final long serialVersionUID = -5908509288197150436L;
103    
104        // In version 0.9.12, in response to several developer requests, I changed
105        // the 'data' attribute from 'private' to 'protected', so that others can
106        // make subclasses that work directly with the underlying data structure.
107    
108        /** Storage for the data items in the series. */
109        protected List data;
110    
111        /** The maximum number of items for the series. */
112        private int maximumItemCount = Integer.MAX_VALUE;
113    
114        /**
115         * A flag that controls whether the items are automatically sorted
116         * (by x-value ascending).
117         */
118        private boolean autoSort;
119    
120        /** A flag that controls whether or not duplicate x-values are allowed. */
121        private boolean allowDuplicateXValues;
122    
123        /** The lowest x-value in the series, excluding Double.NaN values. */
124        private double minX;
125    
126        /** The highest x-value in the series, excluding Double.NaN values. */
127        private double maxX;
128    
129        /** The lowest y-value in the series, excluding Double.NaN values. */
130        private double minY;
131    
132        /** The highest y-value in the series, excluding Double.NaN values. */
133        private double maxY;
134    
135        /**
136         * Creates a new empty series.  By default, items added to the series will
137         * be sorted into ascending order by x-value, and duplicate x-values will
138         * be allowed (these defaults can be modified with another constructor.
139         *
140         * @param key  the series key (<code>null</code> not permitted).
141         */
142        public XYSeries(Comparable key) {
143            this(key, true, true);
144        }
145    
146        /**
147         * Constructs a new empty series, with the auto-sort flag set as requested,
148         * and duplicate values allowed.
149         *
150         * @param key  the series key (<code>null</code> not permitted).
151         * @param autoSort  a flag that controls whether or not the items in the
152         *                  series are sorted.
153         */
154        public XYSeries(Comparable key, boolean autoSort) {
155            this(key, autoSort, true);
156        }
157    
158        /**
159         * Constructs a new xy-series that contains no data.  You can specify
160         * whether or not duplicate x-values are allowed for the series.
161         *
162         * @param key  the series key (<code>null</code> not permitted).
163         * @param autoSort  a flag that controls whether or not the items in the
164         *                  series are sorted.
165         * @param allowDuplicateXValues  a flag that controls whether duplicate
166         *                               x-values are allowed.
167         */
168        public XYSeries(Comparable key, boolean autoSort,
169                boolean allowDuplicateXValues) {
170            super(key);
171            this.data = new java.util.ArrayList();
172            this.autoSort = autoSort;
173            this.allowDuplicateXValues = allowDuplicateXValues;
174            this.minX = Double.NaN;
175            this.maxX = Double.NaN;
176            this.minY = Double.NaN;
177            this.maxY = Double.NaN;
178        }
179    
180        /**
181         * Returns the smallest x-value in the series, ignoring any Double.NaN
182         * values.  This method returns Double.NaN if there is no smallest x-value
183         * (for example, when the series is empty).
184         *
185         * @return The smallest x-value.
186         *
187         * @see #getMaxX()
188         *
189         * @since 1.0.13
190         */
191        public double getMinX() {
192            return this.minX;
193        }
194    
195        /**
196         * Returns the largest x-value in the series, ignoring any Double.NaN
197         * values.  This method returns Double.NaN if there is no largest x-value
198         * (for example, when the series is empty).
199         *
200         * @return The largest x-value.
201         *
202         * @see #getMinX()
203         *
204         * @since 1.0.13
205         */
206        public double getMaxX() {
207            return this.maxX;
208        }
209    
210        /**
211         * Returns the smallest y-value in the series, ignoring any null and
212         * Double.NaN values.  This method returns Double.NaN if there is no
213         * smallest y-value (for example, when the series is empty).
214         *
215         * @return The smallest y-value.
216         *
217         * @see #getMaxY()
218         *
219         * @since 1.0.13
220         */
221        public double getMinY() {
222            return this.minY;
223        }
224    
225        /**
226         * Returns the largest y-value in the series, ignoring any Double.NaN
227         * values.  This method returns Double.NaN if there is no largest y-value
228         * (for example, when the series is empty).
229         *
230         * @return The largest y-value.
231         *
232         * @see #getMinY()
233         *
234         * @since 1.0.13
235         */
236        public double getMaxY() {
237            return this.maxY;
238        }
239    
240        /**
241         * Updates the cached values for the minimum and maximum data values.
242         *
243         * @param item  the item added (<code>null</code> not permitted).
244         *
245         * @since 1.0.13
246         */
247        private void updateBoundsForAddedItem(XYDataItem item) {
248            double x = item.getXValue();
249            this.minX = minIgnoreNaN(this.minX, x);
250            this.maxX = maxIgnoreNaN(this.maxX, x);
251            if (item.getY() != null) {
252                double y = item.getYValue();
253                this.minY = minIgnoreNaN(this.minY, y);
254                this.maxY = maxIgnoreNaN(this.maxY, y);
255            }
256        }
257    
258        /**
259         * Updates the cached values for the minimum and maximum data values on
260         * the basis that the specified item has just been removed.
261         *
262         * @param item  the item added (<code>null</code> not permitted).
263         *
264         * @since 1.0.13
265         */
266        private void updateBoundsForRemovedItem(XYDataItem item) {
267            boolean itemContributesToXBounds = false;
268            boolean itemContributesToYBounds = false;
269            double x = item.getXValue();
270            if (!Double.isNaN(x)) {
271                if (x <= this.minX || x >= this.maxX) {
272                    itemContributesToXBounds = true;
273                }
274            }
275            if (item.getY() != null) {
276                double y = item.getYValue();
277                if (!Double.isNaN(y)) {
278                    if (y <= this.minY || y >= this.maxY) {
279                        itemContributesToYBounds = true;
280                    }
281                }
282            }
283            if (itemContributesToYBounds) {
284                findBoundsByIteration();
285            }
286            else if (itemContributesToXBounds) {
287                if (getAutoSort()) {
288                    this.minX = getX(0).doubleValue();
289                    this.maxX = getX(getItemCount() - 1).doubleValue();
290                }
291                else {
292                    findBoundsByIteration();
293                }
294            }
295        }
296    
297        /**
298         * Finds the bounds of the x and y values for the series, by iterating
299         * through all the data items.
300         *
301         * @since 1.0.13
302         */
303        private void findBoundsByIteration() {
304            this.minX = Double.NaN;
305            this.maxX = Double.NaN;
306            this.minY = Double.NaN;
307            this.maxY = Double.NaN;
308            Iterator iterator = this.data.iterator();
309            while (iterator.hasNext()) {
310                XYDataItem item = (XYDataItem) iterator.next();
311                updateBoundsForAddedItem(item);
312            }
313        }
314    
315        /**
316         * Returns the flag that controls whether the items in the series are
317         * automatically sorted.  There is no setter for this flag, it must be
318         * defined in the series constructor.
319         *
320         * @return A boolean.
321         */
322        public boolean getAutoSort() {
323            return this.autoSort;
324        }
325    
326        /**
327         * Returns a flag that controls whether duplicate x-values are allowed.
328         * This flag can only be set in the constructor.
329         *
330         * @return A boolean.
331         */
332        public boolean getAllowDuplicateXValues() {
333            return this.allowDuplicateXValues;
334        }
335    
336        /**
337         * Returns the number of items in the series.
338         *
339         * @return The item count.
340         *
341         * @see #getItems()
342         */
343        public int getItemCount() {
344            return this.data.size();
345        }
346    
347        /**
348         * Returns the list of data items for the series (the list contains
349         * {@link XYDataItem} objects and is unmodifiable).
350         *
351         * @return The list of data items.
352         */
353        public List getItems() {
354            return Collections.unmodifiableList(this.data);
355        }
356    
357        /**
358         * Returns the maximum number of items that will be retained in the series.
359         * The default value is <code>Integer.MAX_VALUE</code>.
360         *
361         * @return The maximum item count.
362         *
363         * @see #setMaximumItemCount(int)
364         */
365        public int getMaximumItemCount() {
366            return this.maximumItemCount;
367        }
368    
369        /**
370         * Sets the maximum number of items that will be retained in the series.
371         * If you add a new item to the series such that the number of items will
372         * exceed the maximum item count, then the first element in the series is
373         * automatically removed, ensuring that the maximum item count is not
374         * exceeded.
375         * <p>
376         * Typically this value is set before the series is populated with data,
377         * but if it is applied later, it may cause some items to be removed from
378         * the series (in which case a {@link SeriesChangeEvent} will be sent to
379         * all registered listeners).
380         *
381         * @param maximum  the maximum number of items for the series.
382         */
383        public void setMaximumItemCount(int maximum) {
384            this.maximumItemCount = maximum;
385            int remove = this.data.size() - maximum;
386            if (remove > 0) {
387                this.data.subList(0, remove).clear();
388                findBoundsByIteration();
389                fireSeriesChanged();
390            }
391        }
392    
393        /**
394         * Adds a data item to the series and sends a {@link SeriesChangeEvent} to
395         * all registered listeners.
396         *
397         * @param item  the (x, y) item (<code>null</code> not permitted).
398         */
399        public void add(XYDataItem item) {
400            // argument checking delegated...
401            add(item, true);
402        }
403    
404        /**
405         * Adds a data item to the series and sends a {@link SeriesChangeEvent} to
406         * all registered listeners.
407         *
408         * @param x  the x value.
409         * @param y  the y value.
410         */
411        public void add(double x, double y) {
412            add(new Double(x), new Double(y), true);
413        }
414    
415        /**
416         * Adds a data item to the series and, if requested, sends a
417         * {@link SeriesChangeEvent} to all registered listeners.
418         *
419         * @param x  the x value.
420         * @param y  the y value.
421         * @param notify  a flag that controls whether or not a
422         *                {@link SeriesChangeEvent} is sent to all registered
423         *                listeners.
424         */
425        public void add(double x, double y, boolean notify) {
426            add(new Double(x), new Double(y), notify);
427        }
428    
429        /**
430         * Adds a data item to the series and sends a {@link SeriesChangeEvent} to
431         * all registered listeners.  The unusual pairing of parameter types is to
432         * make it easier to add <code>null</code> y-values.
433         *
434         * @param x  the x value.
435         * @param y  the y value (<code>null</code> permitted).
436         */
437        public void add(double x, Number y) {
438            add(new Double(x), y);
439        }
440    
441        /**
442         * Adds a data item to the series and, if requested, sends a
443         * {@link SeriesChangeEvent} to all registered listeners.  The unusual
444         * pairing of parameter types is to make it easier to add null y-values.
445         *
446         * @param x  the x value.
447         * @param y  the y value (<code>null</code> permitted).
448         * @param notify  a flag that controls whether or not a
449         *                {@link SeriesChangeEvent} is sent to all registered
450         *                listeners.
451         */
452        public void add(double x, Number y, boolean notify) {
453            add(new Double(x), y, notify);
454        }
455    
456        /**
457         * Adds a new data item to the series (in the correct position if the
458         * <code>autoSort</code> flag is set for the series) and sends a
459         * {@link SeriesChangeEvent} to all registered listeners.
460         * <P>
461         * Throws an exception if the x-value is a duplicate AND the
462         * allowDuplicateXValues flag is false.
463         *
464         * @param x  the x-value (<code>null</code> not permitted).
465         * @param y  the y-value (<code>null</code> permitted).
466         *
467         * @throws SeriesException if the x-value is a duplicate and the
468         *     <code>allowDuplicateXValues</code> flag is not set for this series.
469         */
470        public void add(Number x, Number y) {
471            // argument checking delegated...
472            add(x, y, true);
473        }
474    
475        /**
476         * Adds new data to the series and, if requested, sends a
477         * {@link SeriesChangeEvent} to all registered listeners.
478         * <P>
479         * Throws an exception if the x-value is a duplicate AND the
480         * allowDuplicateXValues flag is false.
481         *
482         * @param x  the x-value (<code>null</code> not permitted).
483         * @param y  the y-value (<code>null</code> permitted).
484         * @param notify  a flag the controls whether or not a
485         *                {@link SeriesChangeEvent} is sent to all registered
486         *                listeners.
487         */
488        public void add(Number x, Number y, boolean notify) {
489            // delegate argument checking to XYDataItem...
490            XYDataItem item = new XYDataItem(x, y);
491            add(item, notify);
492        }
493    
494        /**
495         * Adds a data item to the series and, if requested, sends a
496         * {@link SeriesChangeEvent} to all registered listeners.
497         *
498         * @param item  the (x, y) item (<code>null</code> not permitted).
499         * @param notify  a flag that controls whether or not a
500         *                {@link SeriesChangeEvent} is sent to all registered
501         *                listeners.
502         */
503        public void add(XYDataItem item, boolean notify) {
504            if (item == null) {
505                throw new IllegalArgumentException("Null 'item' argument.");
506            }
507            item = (XYDataItem) item.clone();
508            if (this.autoSort) {
509                int index = Collections.binarySearch(this.data, item);
510                if (index < 0) {
511                    this.data.add(-index - 1, item);
512                }
513                else {
514                    if (this.allowDuplicateXValues) {
515                        // need to make sure we are adding *after* any duplicates
516                        int size = this.data.size();
517                        while (index < size && item.compareTo(
518                                this.data.get(index)) == 0) {
519                            index++;
520                        }
521                        if (index < this.data.size()) {
522                            this.data.add(index, item);
523                        }
524                        else {
525                            this.data.add(item);
526                        }
527                    }
528                    else {
529                        throw new SeriesException("X-value already exists.");
530                    }
531                }
532            }
533            else {
534                if (!this.allowDuplicateXValues) {
535                    // can't allow duplicate values, so we need to check whether
536                    // there is an item with the given x-value already
537                    int index = indexOf(item.getX());
538                    if (index >= 0) {
539                        throw new SeriesException("X-value already exists.");
540                    }
541                }
542                this.data.add(item);
543            }
544            updateBoundsForAddedItem(item);
545            if (getItemCount() > this.maximumItemCount) {
546                XYDataItem removed = (XYDataItem) this.data.remove(0);
547                updateBoundsForRemovedItem(removed);
548            }
549            if (notify) {
550                fireSeriesChanged();
551            }
552        }
553    
554        /**
555         * Deletes a range of items from the series and sends a
556         * {@link SeriesChangeEvent} to all registered listeners.
557         *
558         * @param start  the start index (zero-based).
559         * @param end  the end index (zero-based).
560         */
561        public void delete(int start, int end) {
562            this.data.subList(start, end + 1).clear();
563            findBoundsByIteration();
564            fireSeriesChanged();
565        }
566    
567        /**
568         * Removes the item at the specified index and sends a
569         * {@link SeriesChangeEvent} to all registered listeners.
570         *
571         * @param index  the index.
572         *
573         * @return The item removed.
574         */
575        public XYDataItem remove(int index) {
576            XYDataItem removed = (XYDataItem) this.data.remove(index);
577            updateBoundsForRemovedItem(removed);
578            fireSeriesChanged();
579            return removed;
580        }
581    
582        /**
583         * Removes an item with the specified x-value and sends a
584         * {@link SeriesChangeEvent} to all registered listeners.  Note that when
585         * a series permits multiple items with the same x-value, this method
586         * could remove any one of the items with that x-value.
587         *
588         * @param x  the x-value.
589    
590         * @return The item removed.
591         */
592        public XYDataItem remove(Number x) {
593            return remove(indexOf(x));
594        }
595    
596        /**
597         * Removes all data items from the series and sends a
598         * {@link SeriesChangeEvent} to all registered listeners.
599         */
600        public void clear() {
601            if (this.data.size() > 0) {
602                this.data.clear();
603                this.minX = Double.NaN;
604                this.maxX = Double.NaN;
605                this.minY = Double.NaN;
606                this.maxY = Double.NaN;
607                fireSeriesChanged();
608            }
609        }
610    
611        /**
612         * Return the data item with the specified index.
613         *
614         * @param index  the index.
615         *
616         * @return The data item with the specified index.
617         */
618        public XYDataItem getDataItem(int index) {
619            XYDataItem item = (XYDataItem) this.data.get(index);
620            return (XYDataItem) item.clone();
621        }
622    
623        /**
624         * Return the data item with the specified index.
625         *
626         * @param index  the index.
627         *
628         * @return The data item with the specified index.
629         *
630         * @since 1.0.14
631         */
632        XYDataItem getRawDataItem(int index) {
633            return (XYDataItem) this.data.get(index);
634        }
635    
636        /**
637         * Returns the x-value at the specified index.
638         *
639         * @param index  the index (zero-based).
640         *
641         * @return The x-value (never <code>null</code>).
642         */
643        public Number getX(int index) {
644            return getRawDataItem(index).getX();
645        }
646    
647        /**
648         * Returns the y-value at the specified index.
649         *
650         * @param index  the index (zero-based).
651         *
652         * @return The y-value (possibly <code>null</code>).
653         */
654        public Number getY(int index) {
655            return getRawDataItem(index).getY();
656        }
657    
658        /**
659         * Updates the value of an item in the series and sends a
660         * {@link SeriesChangeEvent} to all registered listeners.
661         *
662         * @param index  the item (zero based index).
663         * @param y  the new value (<code>null</code> permitted).
664         *
665         * @deprecated Renamed {@link #updateByIndex(int, Number)} to avoid
666         *         confusion with the {@link #update(Number, Number)} method.
667         */
668        public void update(int index, Number y) {
669            XYDataItem item = getRawDataItem(index);
670    
671            // figure out if we need to iterate through all the y-values
672            boolean iterate = false;
673            double oldY = item.getYValue();
674            if (!Double.isNaN(oldY)) {
675                iterate = oldY <= this.minY || oldY >= this.maxY;
676            }
677            item.setY(y);
678    
679            if (iterate) {
680                findBoundsByIteration();
681            }
682            else if (y != null) {
683                double yy = y.doubleValue();
684                this.minY = minIgnoreNaN(this.minY, yy);
685                this.maxY = maxIgnoreNaN(this.maxY, yy);
686            }
687            fireSeriesChanged();
688        }
689    
690        /**
691         * A function to find the minimum of two values, but ignoring any
692         * Double.NaN values.
693         *
694         * @param a  the first value.
695         * @param b  the second value.
696         *
697         * @return The minimum of the two values.
698         */
699        private double minIgnoreNaN(double a, double b) {
700            if (Double.isNaN(a)) {
701                return b;
702            }
703            if (Double.isNaN(b)) {
704                return a;
705            }
706            return Math.min(a, b);
707        }
708    
709        /**
710         * A function to find the maximum of two values, but ignoring any
711         * Double.NaN values.
712         *
713         * @param a  the first value.
714         * @param b  the second value.
715         *
716         * @return The maximum of the two values.
717         */
718        private double maxIgnoreNaN(double a, double b) {
719            if (Double.isNaN(a)) {
720                return b;
721            }
722            if (Double.isNaN(b)) {
723                return a;
724            }
725            return Math.max(a, b);
726        }
727    
728        /**
729         * Updates the value of an item in the series and sends a
730         * {@link SeriesChangeEvent} to all registered listeners.
731         *
732         * @param index  the item (zero based index).
733         * @param y  the new value (<code>null</code> permitted).
734         *
735         * @since 1.0.1
736         */
737        public void updateByIndex(int index, Number y) {
738            update(index, y);
739        }
740    
741        /**
742         * Updates an item in the series.
743         *
744         * @param x  the x-value (<code>null</code> not permitted).
745         * @param y  the y-value (<code>null</code> permitted).
746         *
747         * @throws SeriesException if there is no existing item with the specified
748         *         x-value.
749         */
750        public void update(Number x, Number y) {
751            int index = indexOf(x);
752            if (index < 0) {
753                throw new SeriesException("No observation for x = " + x);
754            }
755            updateByIndex(index, y);
756        }
757    
758        /**
759         * Adds or updates an item in the series and sends a
760         * {@link SeriesChangeEvent} to all registered listeners.
761         *
762         * @param x  the x-value.
763         * @param y  the y-value.
764         *
765         * @return The item that was overwritten, if any.
766         *
767         * @since 1.0.10
768         */
769        public XYDataItem addOrUpdate(double x, double y) {
770            return addOrUpdate(new Double(x), new Double(y));
771        }
772    
773        /**
774         * Adds or updates an item in the series and sends a
775         * {@link SeriesChangeEvent} to all registered listeners.
776         *
777         * @param x  the x-value (<code>null</code> not permitted).
778         * @param y  the y-value (<code>null</code> permitted).
779         *
780         * @return A copy of the overwritten data item, or <code>null</code> if no
781         *         item was overwritten.
782         */
783        public XYDataItem addOrUpdate(Number x, Number y) {
784            // defer argument checking
785            return addOrUpdate(new XYDataItem(x, y));
786        }
787    
788        /**
789         * Adds or updates an item in the series and sends a
790         * {@link SeriesChangeEvent} to all registered listeners.
791         *
792         * @param item  the data item (<code>null</code> not permitted).
793         *
794         * @return A copy of the overwritten data item, or <code>null</code> if no
795         *         item was overwritten.
796         *
797         * @since 1.0.14
798         */
799        public XYDataItem addOrUpdate(XYDataItem item) {
800            if (item == null) {
801                throw new IllegalArgumentException("Null 'item' argument.");
802            }
803            if (this.allowDuplicateXValues) {
804                add(item);
805                return null;
806            }
807    
808            // if we get to here, we know that duplicate X values are not permitted
809            XYDataItem overwritten = null;
810            int index = indexOf(item.getX());
811            if (index >= 0) {
812                XYDataItem existing = (XYDataItem) this.data.get(index);
813                overwritten = (XYDataItem) existing.clone();
814                // figure out if we need to iterate through all the y-values
815                boolean iterate = false;
816                double oldY = existing.getYValue();
817                if (!Double.isNaN(oldY)) {
818                    iterate = oldY <= this.minY || oldY >= this.maxY;
819                }
820                existing.setY(item.getY());
821    
822                if (iterate) {
823                    findBoundsByIteration();
824                }
825                else if (item.getY() != null) {
826                    double yy = item.getY().doubleValue();
827                    this.minY = minIgnoreNaN(this.minY, yy);
828                    this.maxY = minIgnoreNaN(this.maxY, yy);
829                }
830            }
831            else {
832                // if the series is sorted, the negative index is a result from
833                // Collections.binarySearch() and tells us where to insert the
834                // new item...otherwise it will be just -1 and we should just
835                // append the value to the list...
836                item = (XYDataItem) item.clone();
837                if (this.autoSort) {
838                    this.data.add(-index - 1, item);
839                }
840                else {
841                    this.data.add(item);
842                }
843                updateBoundsForAddedItem(item);
844    
845                // check if this addition will exceed the maximum item count...
846                if (getItemCount() > this.maximumItemCount) {
847                    XYDataItem removed = (XYDataItem) this.data.remove(0);
848                    updateBoundsForRemovedItem(removed);
849                }
850            }
851            fireSeriesChanged();
852            return overwritten;
853        }
854    
855        /**
856         * Returns the index of the item with the specified x-value, or a negative
857         * index if the series does not contain an item with that x-value.  Be
858         * aware that for an unsorted series, the index is found by iterating
859         * through all items in the series.
860         *
861         * @param x  the x-value (<code>null</code> not permitted).
862         *
863         * @return The index.
864         */
865        public int indexOf(Number x) {
866            if (this.autoSort) {
867                return Collections.binarySearch(this.data, new XYDataItem(x, null));
868            }
869            else {
870                for (int i = 0; i < this.data.size(); i++) {
871                    XYDataItem item = (XYDataItem) this.data.get(i);
872                    if (item.getX().equals(x)) {
873                        return i;
874                    }
875                }
876                return -1;
877            }
878        }
879    
880        /**
881         * Returns a new array containing the x and y values from this series.
882         *
883         * @return A new array containing the x and y values from this series.
884         *
885         * @since 1.0.4
886         */
887        public double[][] toArray() {
888            int itemCount = getItemCount();
889            double[][] result = new double[2][itemCount];
890            for (int i = 0; i < itemCount; i++) {
891                result[0][i] = this.getX(i).doubleValue();
892                Number y = getY(i);
893                if (y != null) {
894                    result[1][i] = y.doubleValue();
895                }
896                else {
897                    result[1][i] = Double.NaN;
898                }
899            }
900            return result;
901        }
902    
903        /**
904         * Returns a clone of the series.
905         *
906         * @return A clone of the series.
907         *
908         * @throws CloneNotSupportedException if there is a cloning problem.
909         */
910        public Object clone() throws CloneNotSupportedException {
911            XYSeries clone = (XYSeries) super.clone();
912            clone.data = (List) ObjectUtilities.deepClone(this.data);
913            return clone;
914        }
915    
916        /**
917         * Creates a new series by copying a subset of the data in this time series.
918         *
919         * @param start  the index of the first item to copy.
920         * @param end  the index of the last item to copy.
921         *
922         * @return A series containing a copy of this series from start until end.
923         *
924         * @throws CloneNotSupportedException if there is a cloning problem.
925         */
926        public XYSeries createCopy(int start, int end)
927                throws CloneNotSupportedException {
928    
929            XYSeries copy = (XYSeries) super.clone();
930            copy.data = new java.util.ArrayList();
931            if (this.data.size() > 0) {
932                for (int index = start; index <= end; index++) {
933                    XYDataItem item = (XYDataItem) this.data.get(index);
934                    XYDataItem clone = (XYDataItem) item.clone();
935                    try {
936                        copy.add(clone);
937                    }
938                    catch (SeriesException e) {
939                        System.err.println("Unable to add cloned data item.");
940                    }
941                }
942            }
943            return copy;
944    
945        }
946    
947        /**
948         * Tests this series for equality with an arbitrary object.
949         *
950         * @param obj  the object to test against for equality
951         *             (<code>null</code> permitted).
952         *
953         * @return A boolean.
954         */
955        public boolean equals(Object obj) {
956            if (obj == this) {
957                return true;
958            }
959            if (!(obj instanceof XYSeries)) {
960                return false;
961            }
962            if (!super.equals(obj)) {
963                return false;
964            }
965            XYSeries that = (XYSeries) obj;
966            if (this.maximumItemCount != that.maximumItemCount) {
967                return false;
968            }
969            if (this.autoSort != that.autoSort) {
970                return false;
971            }
972            if (this.allowDuplicateXValues != that.allowDuplicateXValues) {
973                return false;
974            }
975            if (!ObjectUtilities.equal(this.data, that.data)) {
976                return false;
977            }
978            return true;
979        }
980    
981        /**
982         * Returns a hash code.
983         *
984         * @return A hash code.
985         */
986        public int hashCode() {
987            int result = super.hashCode();
988            // it is too slow to look at every data item, so let's just look at
989            // the first, middle and last items...
990            int count = getItemCount();
991            if (count > 0) {
992                XYDataItem item = getRawDataItem(0);
993                result = 29 * result + item.hashCode();
994            }
995            if (count > 1) {
996                XYDataItem item = getRawDataItem(count - 1);
997                result = 29 * result + item.hashCode();
998            }
999            if (count > 2) {
1000                XYDataItem item = getRawDataItem(count / 2);
1001                result = 29 * result + item.hashCode();
1002            }
1003            result = 29 * result + this.maximumItemCount;
1004            result = 29 * result + (this.autoSort ? 1 : 0);
1005            result = 29 * result + (this.allowDuplicateXValues ? 1 : 0);
1006            return result;
1007        }
1008    
1009    }
1010