001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2007, 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     * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
025     * in the United States and other countries.]
026     *
027     * ---------------------
028     * DatasetUtilities.java
029     * ---------------------
030     * (C) Copyright 2000-2007, by Object Refinery Limited and Contributors.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   Andrzej Porebski (bug fix);
034     *                   Jonathan Nash (bug fix);
035     *                   Richard Atkinson;
036     *                   Andreas Schroeder;
037     *
038     * $Id: DatasetUtilities.java,v 1.18.2.8 2007/06/12 14:54:30 mungady Exp $
039     *
040     * Changes (from 18-Sep-2001)
041     * --------------------------
042     * 18-Sep-2001 : Added standard header and fixed DOS encoding problem (DG);
043     * 22-Oct-2001 : Renamed DataSource.java --> Dataset.java etc. (DG);
044     * 15-Nov-2001 : Moved to package com.jrefinery.data.* in the JCommon class 
045     *               library (DG);
046     *               Changed to handle null values from datasets (DG);
047     *               Bug fix (thanks to Andrzej Porebski) - initial value now set 
048     *               to positive or negative infinity when iterating (DG);
049     * 22-Nov-2001 : Datasets with containing no data now return null for min and 
050     *               max calculations (DG);
051     * 13-Dec-2001 : Extended to handle HighLowDataset and IntervalXYDataset (DG);
052     * 15-Feb-2002 : Added getMinimumStackedRangeValue() and 
053     *               getMaximumStackedRangeValue() (DG);
054     * 28-Feb-2002 : Renamed Datasets.java --> DatasetUtilities.java (DG);
055     * 18-Mar-2002 : Fixed bug in min/max domain calculation for datasets that 
056     *               implement the CategoryDataset interface AND the XYDataset 
057     *               interface at the same time.  Thanks to Jonathan Nash for the 
058     *               fix (DG);
059     * 23-Apr-2002 : Added getDomainExtent() and getRangeExtent() methods (DG);
060     * 13-Jun-2002 : Modified range measurements to handle 
061     *               IntervalCategoryDataset (DG);
062     * 12-Jul-2002 : Method name change in DomainInfo interface (DG);
063     * 30-Jul-2002 : Added pie dataset summation method (DG);
064     * 01-Oct-2002 : Added a method for constructing an XYDataset from a Function2D
065     *               instance (DG);
066     * 24-Oct-2002 : Amendments required following changes to the CategoryDataset 
067     *               interface (DG);
068     * 18-Nov-2002 : Changed CategoryDataset to TableDataset (DG);
069     * 04-Mar-2003 : Added isEmpty(XYDataset) method (DG);
070     * 05-Mar-2003 : Added a method for creating a CategoryDataset from a 
071     *               KeyedValues instance (DG);
072     * 15-May-2003 : Renamed isEmpty --> isEmptyOrNull (DG);
073     * 25-Jun-2003 : Added limitPieDataset methods (RA);
074     * 26-Jun-2003 : Modified getDomainExtent() method to accept null datasets (DG);
075     * 27-Jul-2003 : Added getStackedRangeExtent(TableXYDataset data) (RA);
076     * 18-Aug-2003 : getStackedRangeExtent(TableXYDataset data) now handles null 
077     *               values (RA);
078     * 02-Sep-2003 : Added method to check for null or empty PieDataset (DG);
079     * 18-Sep-2003 : Fix for bug 803660 (getMaximumRangeValue for 
080     *               CategoryDataset) (DG);
081     * 20-Oct-2003 : Added getCumulativeRangeExtent() method (DG);
082     * 09-Jan-2003 : Added argument checking code to the createCategoryDataset() 
083     *               method (DG);
084     * 23-Mar-2004 : Fixed bug in getMaximumStackedRangeValue() method (DG);
085     * 31-Mar-2004 : Exposed the extent iteration algorithms to use one of them and 
086     *               applied noninstantiation pattern (AS);
087     * 11-May-2004 : Renamed getPieDatasetTotal --> calculatePieDatasetTotal (DG);
088     * 15-Jul-2004 : Switched getX() with getXValue() and getY() with getYValue();
089     * 24-Aug-2004 : Added argument checks to createCategoryDataset() method (DG);
090     * 04-Oct-2004 : Renamed ArrayUtils --> ArrayUtilities (DG);
091     * 06-Oct-2004 : Renamed findDomainExtent() --> findDomainBounds(),
092     *               findRangeExtent() --> findRangeBounds() (DG);
093     * 07-Jan-2005 : Renamed findStackedRangeExtent() --> findStackedRangeBounds(),
094     *               findCumulativeRangeExtent() --> findCumulativeRangeBounds(),
095     *               iterateXYRangeExtent() --> iterateXYRangeBounds(), 
096     *               removed deprecated methods (DG);
097     * 03-Feb-2005 : The findStackedRangeBounds() methods now return null for 
098     *               empty datasets (DG);
099     * 03-Mar-2005 : Moved createNumberArray() and createNumberArray2D() methods
100     *               from DatasetUtilities --> DataUtilities (DG);
101     * 22-Sep-2005 : Added new findStackedRangeBounds() method that takes base
102     *               argument (DG);
103     * ------------- JFREECHART 1.0.x ---------------------------------------------
104     * 15-Mar-2007 : Added calculateStackTotal() method (DG);
105     * 
106     */
107    
108    package org.jfree.data.general;
109    
110    import java.util.ArrayList;
111    import java.util.Iterator;
112    import java.util.List;
113    
114    import org.jfree.data.DomainInfo;
115    import org.jfree.data.KeyToGroupMap;
116    import org.jfree.data.KeyedValues;
117    import org.jfree.data.Range;
118    import org.jfree.data.RangeInfo;
119    import org.jfree.data.category.CategoryDataset;
120    import org.jfree.data.category.DefaultCategoryDataset;
121    import org.jfree.data.category.IntervalCategoryDataset;
122    import org.jfree.data.function.Function2D;
123    import org.jfree.data.xy.IntervalXYDataset;
124    import org.jfree.data.xy.OHLCDataset;
125    import org.jfree.data.xy.TableXYDataset;
126    import org.jfree.data.xy.XYDataset;
127    import org.jfree.data.xy.XYSeries;
128    import org.jfree.data.xy.XYSeriesCollection;
129    import org.jfree.util.ArrayUtilities;
130    
131    /**
132     * A collection of useful static methods relating to datasets.
133     */
134    public final class DatasetUtilities {
135        
136        /**
137         * Private constructor for non-instanceability.
138         */
139        private DatasetUtilities() {
140            // now try to instantiate this ;-)
141        }
142    
143        /**
144         * Calculates the total of all the values in a {@link PieDataset}.  If 
145         * the dataset contains negative or <code>null</code> values, they are 
146         * ignored. 
147         *
148         * @param dataset  the dataset (<code>null</code> not permitted).
149         *
150         * @return The total.
151         */
152        public static double calculatePieDatasetTotal(PieDataset dataset) {
153            if (dataset == null) {
154                throw new IllegalArgumentException("Null 'dataset' argument.");
155            }
156            List keys = dataset.getKeys();
157            double totalValue = 0;
158            Iterator iterator = keys.iterator();
159            while (iterator.hasNext()) {
160                Comparable current = (Comparable) iterator.next();
161                if (current != null) {
162                    Number value = dataset.getValue(current);
163                    double v = 0.0;
164                    if (value != null) {
165                        v = value.doubleValue();
166                    }
167                    if (v > 0) {
168                        totalValue = totalValue + v;
169                    }
170                }
171            }
172            return totalValue;
173        }
174    
175        /**
176         * Creates a pie dataset from a table dataset by taking all the values
177         * for a single row.
178         *
179         * @param dataset  the dataset (<code>null</code> not permitted).
180         * @param rowKey  the row key.
181         *
182         * @return A pie dataset.
183         */
184        public static PieDataset createPieDatasetForRow(CategoryDataset dataset, 
185                                                        Comparable rowKey) {
186            int row = dataset.getRowIndex(rowKey);
187            return createPieDatasetForRow(dataset, row);
188        }
189    
190        /**
191         * Creates a pie dataset from a table dataset by taking all the values
192         * for a single row.
193         *
194         * @param dataset  the dataset (<code>null</code> not permitted).
195         * @param row  the row (zero-based index).
196         *
197         * @return A pie dataset.
198         */
199        public static PieDataset createPieDatasetForRow(CategoryDataset dataset, 
200                                                        int row) {
201            DefaultPieDataset result = new DefaultPieDataset();
202            int columnCount = dataset.getColumnCount();
203            for (int current = 0; current < columnCount; current++) {
204                Comparable columnKey = dataset.getColumnKey(current);
205                result.setValue(columnKey, dataset.getValue(row, current));
206            }
207            return result;
208        }
209    
210        /**
211         * Creates a pie dataset from a table dataset by taking all the values
212         * for a single column.
213         *
214         * @param dataset  the dataset (<code>null</code> not permitted).
215         * @param columnKey  the column key.
216         *
217         * @return A pie dataset.
218         */
219        public static PieDataset createPieDatasetForColumn(CategoryDataset dataset,
220                                                           Comparable columnKey) {
221            int column = dataset.getColumnIndex(columnKey);
222            return createPieDatasetForColumn(dataset, column);
223        }
224    
225        /**
226         * Creates a pie dataset from a {@link CategoryDataset} by taking all the 
227         * values for a single column.
228         *
229         * @param dataset  the dataset (<code>null</code> not permitted).
230         * @param column  the column (zero-based index).
231         *
232         * @return A pie dataset.
233         */
234        public static PieDataset createPieDatasetForColumn(CategoryDataset dataset, 
235                                                           int column) {
236            DefaultPieDataset result = new DefaultPieDataset();
237            int rowCount = dataset.getRowCount();
238            for (int i = 0; i < rowCount; i++) {
239                Comparable rowKey = dataset.getRowKey(i);
240                result.setValue(rowKey, dataset.getValue(i, column));
241            }
242            return result;
243        }
244    
245        /**
246         * Creates a new pie dataset based on the supplied dataset, but modified
247         * by aggregating all the low value items (those whose value is lower
248         * than the <code>percentThreshold</code>) into a single item with the
249         * key "Other".
250         *
251         * @param source  the source dataset (<code>null</code> not permitted).
252         * @param key  a new key for the aggregated items (<code>null</code> not
253         *             permitted).
254         * @param minimumPercent  the percent threshold.
255         * 
256         * @return The pie dataset with (possibly) aggregated items.
257         */
258        public static PieDataset createConsolidatedPieDataset(PieDataset source, 
259                                                              Comparable key,
260                                                              double minimumPercent)
261        {
262            return DatasetUtilities.createConsolidatedPieDataset(
263                source, key, minimumPercent, 2
264            );
265        }
266    
267        /**
268         * Creates a new pie dataset based on the supplied dataset, but modified 
269         * by aggregating all the low value items (those whose value is lower 
270         * than the <code>percentThreshold</code>) into a single item.  The 
271         * aggregated items are assigned the specified key.  Aggregation only 
272         * occurs if there are at least <code>minItems</code> items to aggregate.
273         *
274         * @param source  the source dataset (<code>null</code> not permitted).
275         * @param key  the key to represent the aggregated items.
276         * @param minimumPercent  the percent threshold (ten percent is 0.10).
277         * @param minItems  only aggregate low values if there are at least this 
278         *                  many.
279         * 
280         * @return The pie dataset with (possibly) aggregated items.
281         */
282        public static PieDataset createConsolidatedPieDataset(PieDataset source,
283                                                              Comparable key,
284                                                              double minimumPercent,
285                                                              int minItems) {
286            
287            DefaultPieDataset result = new DefaultPieDataset();
288            double total = DatasetUtilities.calculatePieDatasetTotal(source);
289    
290            //  Iterate and find all keys below threshold percentThreshold
291            List keys = source.getKeys();
292            ArrayList otherKeys = new ArrayList();
293            Iterator iterator = keys.iterator();
294            while (iterator.hasNext()) {
295                Comparable currentKey = (Comparable) iterator.next();
296                Number dataValue = source.getValue(currentKey);
297                if (dataValue != null) {
298                    double value = dataValue.doubleValue();
299                    if (value / total < minimumPercent) {
300                        otherKeys.add(currentKey);
301                    }
302                }
303            }
304    
305            //  Create new dataset with keys above threshold percentThreshold
306            iterator = keys.iterator();
307            double otherValue = 0;
308            while (iterator.hasNext()) {
309                Comparable currentKey = (Comparable) iterator.next();
310                Number dataValue = source.getValue(currentKey);
311                if (dataValue != null) {
312                    if (otherKeys.contains(currentKey) 
313                        && otherKeys.size() >= minItems) {
314                        //  Do not add key to dataset
315                        otherValue += dataValue.doubleValue();
316                    }
317                    else {
318                        //  Add key to dataset
319                        result.setValue(currentKey, dataValue);
320                    }
321                }
322            }
323            //  Add other category if applicable
324            if (otherKeys.size() >= minItems) {
325                result.setValue(key, otherValue);
326            }
327            return result;
328        }
329    
330        /**
331         * Creates a {@link CategoryDataset} that contains a copy of the data in an
332         * array (instances of <code>Double</code> are created to represent the 
333         * data items).
334         * <p>
335         * Row and column keys are created by appending 0, 1, 2, ... to the 
336         * supplied prefixes.
337         *
338         * @param rowKeyPrefix  the row key prefix.
339         * @param columnKeyPrefix  the column key prefix.
340         * @param data  the data.
341         *
342         * @return The dataset.
343         */
344        public static CategoryDataset createCategoryDataset(String rowKeyPrefix,
345                                                            String columnKeyPrefix,
346                                                            double[][] data) {
347    
348            DefaultCategoryDataset result = new DefaultCategoryDataset();
349            for (int r = 0; r < data.length; r++) {
350                String rowKey = rowKeyPrefix + (r + 1);
351                for (int c = 0; c < data[r].length; c++) {
352                    String columnKey = columnKeyPrefix + (c + 1);
353                    result.addValue(new Double(data[r][c]), rowKey, columnKey);
354                }
355            }
356            return result;
357    
358        }
359    
360        /**
361         * Creates a {@link CategoryDataset} that contains a copy of the data in 
362         * an array.
363         * <p>
364         * Row and column keys are created by appending 0, 1, 2, ... to the 
365         * supplied prefixes.
366         *
367         * @param rowKeyPrefix  the row key prefix.
368         * @param columnKeyPrefix  the column key prefix.
369         * @param data  the data.
370         *
371         * @return The dataset.
372         */
373        public static CategoryDataset createCategoryDataset(String rowKeyPrefix,
374                                                            String columnKeyPrefix,
375                                                            Number[][] data) {
376    
377            DefaultCategoryDataset result = new DefaultCategoryDataset();
378            for (int r = 0; r < data.length; r++) {
379                String rowKey = rowKeyPrefix + (r + 1);
380                for (int c = 0; c < data[r].length; c++) {
381                    String columnKey = columnKeyPrefix + (c + 1);
382                    result.addValue(data[r][c], rowKey, columnKey);
383                }
384            }
385            return result;
386    
387        }
388    
389        /**
390         * Creates a {@link CategoryDataset} that contains a copy of the data in 
391         * an array (instances of <code>Double</code> are created to represent the 
392         * data items).
393         * <p>
394         * Row and column keys are taken from the supplied arrays.
395         *
396         * @param rowKeys  the row keys (<code>null</code> not permitted).
397         * @param columnKeys  the column keys (<code>null</code> not permitted).
398         * @param data  the data.
399         *
400         * @return The dataset.
401         */
402        public static CategoryDataset createCategoryDataset(Comparable[] rowKeys,
403                                                            Comparable[] columnKeys,
404                                                            double[][] data) {
405    
406            // check arguments...
407            if (rowKeys == null) {
408                throw new IllegalArgumentException("Null 'rowKeys' argument.");
409            }
410            if (columnKeys == null) {
411                throw new IllegalArgumentException("Null 'columnKeys' argument.");
412            }
413            if (ArrayUtilities.hasDuplicateItems(rowKeys)) {
414                throw new IllegalArgumentException("Duplicate items in 'rowKeys'.");
415            }
416            if (ArrayUtilities.hasDuplicateItems(columnKeys)) {
417                throw new IllegalArgumentException(
418                    "Duplicate items in 'columnKeys'."
419                );
420            }
421            if (rowKeys.length != data.length) {
422                throw new IllegalArgumentException(
423                    "The number of row keys does not match the number of rows in "
424                    + "the data array."
425                );
426            }
427            int columnCount = 0;
428            for (int r = 0; r < data.length; r++) {
429                columnCount = Math.max(columnCount, data[r].length);
430            }
431            if (columnKeys.length != columnCount) {
432                throw new IllegalArgumentException(
433                    "The number of column keys does not match the number of "
434                    + "columns in the data array."
435                );
436            }
437            
438            // now do the work...
439            DefaultCategoryDataset result = new DefaultCategoryDataset();
440            for (int r = 0; r < data.length; r++) {
441                Comparable rowKey = rowKeys[r];
442                for (int c = 0; c < data[r].length; c++) {
443                    Comparable columnKey = columnKeys[c];
444                    result.addValue(new Double(data[r][c]), rowKey, columnKey);
445                }
446            }
447            return result;
448    
449        }
450    
451        /**
452         * Creates a {@link CategoryDataset} by copying the data from the supplied 
453         * {@link KeyedValues} instance.
454         *
455         * @param rowKey  the row key (<code>null</code> not permitted).
456         * @param rowData  the row data (<code>null</code> not permitted).
457         *
458         * @return A dataset.
459         */
460        public static CategoryDataset createCategoryDataset(Comparable rowKey, 
461                                                            KeyedValues rowData) {
462    
463            if (rowKey == null) {
464                throw new IllegalArgumentException("Null 'rowKey' argument.");
465            }
466            if (rowData == null) {
467                throw new IllegalArgumentException("Null 'rowData' argument.");
468            }
469            DefaultCategoryDataset result = new DefaultCategoryDataset();
470            for (int i = 0; i < rowData.getItemCount(); i++) {
471                result.addValue(rowData.getValue(i), rowKey, rowData.getKey(i));
472            }
473            return result;
474    
475        }
476    
477        /**
478         * Creates an {@link XYDataset} by sampling the specified function over a 
479         * fixed range.
480         *
481         * @param f  the function (<code>null</code> not permitted).
482         * @param start  the start value for the range.
483         * @param end  the end value for the range.
484         * @param samples  the number of sample points (must be > 1).
485         * @param seriesKey  the key to give the resulting series 
486         *                   (<code>null</code> not permitted).
487         *
488         * @return A dataset.
489         */
490        public static XYDataset sampleFunction2D(Function2D f, 
491                                                 double start, 
492                                                 double end, 
493                                                 int samples,
494                                                 Comparable seriesKey) {
495    
496            if (f == null) {
497                throw new IllegalArgumentException("Null 'f' argument.");   
498            }
499            if (seriesKey == null) {
500                throw new IllegalArgumentException("Null 'seriesKey' argument.");
501            }
502            if (start >= end) {
503                throw new IllegalArgumentException("Requires 'start' < 'end'.");
504            }
505            if (samples < 2) {
506                throw new IllegalArgumentException("Requires 'samples' > 1");
507            }
508    
509            XYSeries series = new XYSeries(seriesKey);
510            double step = (end - start) / samples;
511            for (int i = 0; i <= samples; i++) {
512                double x = start + (step * i);
513                series.add(x, f.getValue(x));
514            }
515            XYSeriesCollection collection = new XYSeriesCollection(series);
516            return collection;
517    
518        }
519    
520        /**
521         * Returns <code>true</code> if the dataset is empty (or <code>null</code>),
522         * and <code>false</code> otherwise.
523         *
524         * @param dataset  the dataset (<code>null</code> permitted).
525         *
526         * @return A boolean.
527         */
528        public static boolean isEmptyOrNull(PieDataset dataset) {
529    
530            if (dataset == null) {
531                return true;
532            }
533    
534            int itemCount = dataset.getItemCount();
535            if (itemCount == 0) {
536                return true;
537            }
538    
539            for (int item = 0; item < itemCount; item++) {
540                Number y = dataset.getValue(item);
541                if (y != null) {
542                    double yy = y.doubleValue();
543                    if (yy > 0.0) {
544                        return false;
545                    }
546                }
547            }
548    
549            return true;
550    
551        }
552    
553        /**
554         * Returns <code>true</code> if the dataset is empty (or <code>null</code>),
555         * and <code>false</code> otherwise.
556         *
557         * @param dataset  the dataset (<code>null</code> permitted).
558         *
559         * @return A boolean.
560         */
561        public static boolean isEmptyOrNull(CategoryDataset dataset) {
562    
563            if (dataset == null) {
564                return true;
565            }
566    
567            int rowCount = dataset.getRowCount();
568            int columnCount = dataset.getColumnCount();
569            if (rowCount == 0 || columnCount == 0) {
570                return true;
571            }
572    
573            for (int r = 0; r < rowCount; r++) {
574                for (int c = 0; c < columnCount; c++) {
575                    if (dataset.getValue(r, c) != null) {
576                        return false;
577                    }
578    
579                }
580            }
581    
582            return true;
583    
584        }
585    
586        /**
587         * Returns <code>true</code> if the dataset is empty (or <code>null</code>),
588         * and <code>false</code> otherwise.
589         *
590         * @param dataset  the dataset (<code>null</code> permitted).
591         *
592         * @return A boolean.
593         */
594        public static boolean isEmptyOrNull(XYDataset dataset) {
595    
596            boolean result = true;
597    
598            if (dataset != null) {
599                for (int s = 0; s < dataset.getSeriesCount(); s++) {
600                    if (dataset.getItemCount(s) > 0) {
601                        result = false;
602                        continue;
603                    }
604                }
605            }
606    
607            return result;
608    
609        }
610    
611        /**
612         * Returns the range of values in the domain (x-values) of a dataset.
613         *
614         * @param dataset  the dataset (<code>null</code> not permitted).
615         *
616         * @return The range of values (possibly <code>null</code>).
617         */
618        public static Range findDomainBounds(XYDataset dataset) {
619            return findDomainBounds(dataset, true);
620        }
621    
622        /**
623         * Returns the range of values in the domain (x-values) of a dataset.
624         *
625         * @param dataset  the dataset (<code>null</code> not permitted).
626         * @param includeInterval  determines whether or not the x-interval is taken
627         *                         into account (only applies if the dataset is an
628         *                         {@link IntervalXYDataset}).
629         *
630         * @return The range of values (possibly <code>null</code>).
631         */
632        public static Range findDomainBounds(XYDataset dataset, 
633                                             boolean includeInterval) {
634    
635            if (dataset == null) {
636                throw new IllegalArgumentException("Null 'dataset' argument.");
637            }
638    
639            Range result = null;
640            // if the dataset implements DomainInfo, life is easier
641            if (dataset instanceof DomainInfo) {
642                DomainInfo info = (DomainInfo) dataset;
643                result = info.getDomainBounds(includeInterval);
644            }
645            else {
646                result = iterateDomainBounds(dataset, includeInterval);
647            }
648            return result;
649            
650        }
651    
652        /**
653         * Iterates over the items in an {@link XYDataset} to find
654         * the range of x-values. 
655         *  
656         * @param dataset  the dataset (<code>null</code> not permitted).
657         * 
658         * @return The range (possibly <code>null</code>).
659         */
660        public static Range iterateDomainBounds(XYDataset dataset) {
661            return iterateDomainBounds(dataset, true);
662        }
663    
664        /**
665         * Iterates over the items in an {@link XYDataset} to find
666         * the range of x-values. 
667         *  
668         * @param dataset  the dataset (<code>null</code> not permitted).
669         * @param includeInterval  a flag that determines, for an IntervalXYDataset,
670         *                         whether the x-interval or just the x-value is 
671         *                         used to determine the overall range.
672         *   
673         * @return The range (possibly <code>null</code>).
674         */
675        public static Range iterateDomainBounds(XYDataset dataset, 
676                                                boolean includeInterval) {
677            if (dataset == null) {
678                throw new IllegalArgumentException("Null 'dataset' argument.");   
679            }
680            double minimum = Double.POSITIVE_INFINITY;
681            double maximum = Double.NEGATIVE_INFINITY;
682            int seriesCount = dataset.getSeriesCount();
683            double lvalue;
684            double uvalue;
685            if (includeInterval && dataset instanceof IntervalXYDataset) {
686                IntervalXYDataset intervalXYData = (IntervalXYDataset) dataset;
687                for (int series = 0; series < seriesCount; series++) {
688                    int itemCount = dataset.getItemCount(series);
689                    for (int item = 0; item < itemCount; item++) {
690                        lvalue = intervalXYData.getStartXValue(series, item);
691                        uvalue = intervalXYData.getEndXValue(series, item);
692                        minimum = Math.min(minimum, lvalue);
693                        maximum = Math.max(maximum, uvalue);
694                    }
695                }
696            }
697            else {
698                for (int series = 0; series < seriesCount; series++) {
699                    int itemCount = dataset.getItemCount(series);
700                    for (int item = 0; item < itemCount; item++) {
701                        lvalue = dataset.getXValue(series, item);
702                        uvalue = lvalue;
703                        minimum = Math.min(minimum, lvalue);
704                        maximum = Math.max(maximum, uvalue);
705                    }
706                }
707            }
708            if (minimum > maximum) {
709                return null;
710            }
711            else {
712                return new Range(minimum, maximum);
713            }
714        }
715        
716        /**
717         * Returns the range of values in the range for the dataset.
718         *
719         * @param dataset  the dataset (<code>null</code> not permitted).
720         *
721         * @return The range (possibly <code>null</code>).
722         */
723        public static Range findRangeBounds(CategoryDataset dataset) {
724            return findRangeBounds(dataset, true);
725        }
726        
727        /**
728         * Returns the range of values in the range for the dataset.
729         *
730         * @param dataset  the dataset (<code>null</code> not permitted).
731         * @param includeInterval  a flag that determines whether or not the
732         *                         y-interval is taken into account.
733         * 
734         * @return The range (possibly <code>null</code>).
735         */
736        public static Range findRangeBounds(CategoryDataset dataset, 
737                                            boolean includeInterval) {
738            if (dataset == null) {
739                throw new IllegalArgumentException("Null 'dataset' argument.");
740            }
741            Range result = null;
742            if (dataset instanceof RangeInfo) {
743                RangeInfo info = (RangeInfo) dataset;
744                result = info.getRangeBounds(includeInterval);
745            }
746            else {
747                result = iterateCategoryRangeBounds(dataset, includeInterval);
748            }
749            return result;
750        }
751        
752        /**
753         * Returns the range of values in the range for the dataset.  This method
754         * is the partner for the {@link #findDomainBounds(XYDataset)} method.
755         *
756         * @param dataset  the dataset (<code>null</code> not permitted).
757         *
758         * @return The range (possibly <code>null</code>).
759         */
760        public static Range findRangeBounds(XYDataset dataset) {
761            return findRangeBounds(dataset, true);
762        }
763        
764        /**
765         * Returns the range of values in the range for the dataset.  This method
766         * is the partner for the {@link #findDomainBounds(XYDataset)} method.
767         *
768         * @param dataset  the dataset (<code>null</code> not permitted).
769         * @param includeInterval  a flag that determines whether or not the
770         *                         y-interval is taken into account.
771         * 
772         *
773         * @return The range (possibly <code>null</code>).
774         */
775        public static Range findRangeBounds(XYDataset dataset, 
776                                            boolean includeInterval) {
777            if (dataset == null) {
778                throw new IllegalArgumentException("Null 'dataset' argument.");
779            }
780            Range result = null;
781            if (dataset instanceof RangeInfo) {
782                RangeInfo info = (RangeInfo) dataset;
783                result = info.getRangeBounds(includeInterval);
784            }
785            else {
786                result = iterateXYRangeBounds(dataset);
787            }
788            return result;
789        }
790        
791        /**
792         * Iterates over the data item of the category dataset to find
793         * the range bounds.
794         * 
795         * @param dataset  the dataset (<code>null</code> not permitted).
796         * @param includeInterval  a flag that determines whether or not the
797         *                         y-interval is taken into account.
798         * 
799         * @return The range (possibly <code>null</code>).
800         */
801        public static Range iterateCategoryRangeBounds(CategoryDataset dataset, 
802                boolean includeInterval) {
803            double minimum = Double.POSITIVE_INFINITY;
804            double maximum = Double.NEGATIVE_INFINITY;
805            boolean interval = includeInterval 
806                               && dataset instanceof IntervalCategoryDataset;
807            int rowCount = dataset.getRowCount();
808            int columnCount = dataset.getColumnCount();
809            for (int row = 0; row < rowCount; row++) {
810                for (int column = 0; column < columnCount; column++) {
811                    Number lvalue;
812                    Number uvalue;
813                    if (interval) {
814                        IntervalCategoryDataset icd 
815                            = (IntervalCategoryDataset) dataset;
816                        lvalue = icd.getStartValue(row, column);
817                        uvalue = icd.getEndValue(row, column);
818                    }
819                    else {
820                        lvalue = dataset.getValue(row, column);
821                        uvalue = lvalue;
822                    }
823                    if (lvalue != null) {
824                        minimum = Math.min(minimum, lvalue.doubleValue());
825                    }
826                    if (uvalue != null) {
827                        maximum = Math.max(maximum, uvalue.doubleValue());
828                    }
829                }
830            }
831            if (minimum == Double.POSITIVE_INFINITY) {
832                return null;
833            }
834            else {
835                return new Range(minimum, maximum);
836            }
837        }
838        
839        /**
840         * Iterates over the data item of the xy dataset to find
841         * the range bounds.
842         * 
843         * @param dataset  the dataset (<code>null</code> not permitted).
844         * 
845         * @return The range (possibly <code>null</code>).
846         */
847        public static Range iterateXYRangeBounds(XYDataset dataset) {
848            double minimum = Double.POSITIVE_INFINITY;
849            double maximum = Double.NEGATIVE_INFINITY;
850            int seriesCount = dataset.getSeriesCount();
851            for (int series = 0; series < seriesCount; series++) {
852                int itemCount = dataset.getItemCount(series);
853                for (int item = 0; item < itemCount; item++) {
854                    double lvalue;
855                    double uvalue;
856                    if (dataset instanceof IntervalXYDataset) {
857                        IntervalXYDataset intervalXYData 
858                            = (IntervalXYDataset) dataset;
859                        lvalue = intervalXYData.getStartYValue(series, item);
860                        uvalue = intervalXYData.getEndYValue(series, item);
861                    }
862                    else if (dataset instanceof OHLCDataset) {
863                        OHLCDataset highLowData = (OHLCDataset) dataset;
864                        lvalue = highLowData.getLowValue(series, item);
865                        uvalue = highLowData.getHighValue(series, item);
866                    }
867                    else {
868                        lvalue = dataset.getYValue(series, item);
869                        uvalue = lvalue;
870                    }
871                    if (!Double.isNaN(lvalue)) {
872                        minimum = Math.min(minimum, lvalue);
873                    }
874                    if (!Double.isNaN(uvalue)) {     
875                        maximum = Math.max(maximum, uvalue);
876                    }
877                }
878            }
879            if (minimum == Double.POSITIVE_INFINITY) {
880                return null;
881            }
882            else {
883                return new Range(minimum, maximum);
884            }
885        }
886    
887        /**
888         * Finds the minimum domain (or X) value for the specified dataset.  This 
889         * is easy if the dataset implements the {@link DomainInfo} interface (a 
890         * good idea if there is an efficient way to determine the minimum value).
891         * Otherwise, it involves iterating over the entire data-set.
892         * <p>
893         * Returns <code>null</code> if all the data values in the dataset are 
894         * <code>null</code>.
895         *
896         * @param dataset  the dataset (<code>null</code> not permitted).
897         *
898         * @return The minimum value (possibly <code>null</code>).
899         */
900        public static Number findMinimumDomainValue(XYDataset dataset) {
901            if (dataset == null) {
902                throw new IllegalArgumentException("Null 'dataset' argument.");
903            }
904            Number result = null;
905            // if the dataset implements DomainInfo, life is easy
906            if (dataset instanceof DomainInfo) {
907                DomainInfo info = (DomainInfo) dataset;
908                return new Double(info.getDomainLowerBound(true));
909            }
910            else {
911                double minimum = Double.POSITIVE_INFINITY;
912                int seriesCount = dataset.getSeriesCount();
913                for (int series = 0; series < seriesCount; series++) {
914                    int itemCount = dataset.getItemCount(series);
915                    for (int item = 0; item < itemCount; item++) {
916    
917                        double value;
918                        if (dataset instanceof IntervalXYDataset) {
919                            IntervalXYDataset intervalXYData 
920                                = (IntervalXYDataset) dataset;
921                            value = intervalXYData.getStartXValue(series, item);
922                        }
923                        else {
924                            value = dataset.getXValue(series, item);
925                        }
926                        if (!Double.isNaN(value)) {
927                            minimum = Math.min(minimum, value);
928                        }
929    
930                    }
931                }
932                if (minimum == Double.POSITIVE_INFINITY) {
933                    result = null;
934                }
935                else {
936                    result = new Double(minimum);
937                }
938            }
939    
940            return result;
941        }
942        
943        /**
944         * Returns the maximum domain value for the specified dataset.  This is 
945         * easy if the dataset implements the {@link DomainInfo} interface (a good 
946         * idea if there is an efficient way to determine the maximum value).  
947         * Otherwise, it involves iterating over the entire data-set.  Returns 
948         * <code>null</code> if all the data values in the dataset are 
949         * <code>null</code>.
950         *
951         * @param dataset  the dataset (<code>null</code> not permitted).
952         *
953         * @return The maximum value (possibly <code>null</code>).
954         */
955        public static Number findMaximumDomainValue(XYDataset dataset) {
956            if (dataset == null) {
957                throw new IllegalArgumentException("Null 'dataset' argument.");
958            }
959            Number result = null;
960            // if the dataset implements DomainInfo, life is easy
961            if (dataset instanceof DomainInfo) {
962                DomainInfo info = (DomainInfo) dataset;
963                return new Double(info.getDomainUpperBound(true));
964            }
965    
966            // hasn't implemented DomainInfo, so iterate...
967            else {
968                double maximum = Double.NEGATIVE_INFINITY;
969                int seriesCount = dataset.getSeriesCount();
970                for (int series = 0; series < seriesCount; series++) {
971                    int itemCount = dataset.getItemCount(series);
972                    for (int item = 0; item < itemCount; item++) {
973    
974                        double value;
975                        if (dataset instanceof IntervalXYDataset) {
976                            IntervalXYDataset intervalXYData 
977                                = (IntervalXYDataset) dataset;
978                            value = intervalXYData.getEndXValue(series, item);
979                        }
980                        else {
981                            value = dataset.getXValue(series, item);
982                        }
983                        if (!Double.isNaN(value)) {
984                            maximum = Math.max(maximum, value);
985                        }
986                    }
987                }
988                if (maximum == Double.NEGATIVE_INFINITY) {
989                    result = null;
990                }
991                else {
992                    result = new Double(maximum);
993                }
994    
995            }
996            
997            return result;
998        }
999    
1000        /**
1001         * Returns the minimum range value for the specified dataset.  This is 
1002         * easy if the dataset implements the {@link RangeInfo} interface (a good
1003         * idea if there is an efficient way to determine the minimum value).  
1004         * Otherwise, it involves iterating over the entire data-set.  Returns 
1005         * <code>null</code> if all the data values in the dataset are 
1006         * <code>null</code>.
1007         *
1008         * @param dataset  the dataset (<code>null</code> not permitted).
1009         *
1010         * @return The minimum value (possibly <code>null</code>).
1011         */
1012        public static Number findMinimumRangeValue(CategoryDataset dataset) {
1013    
1014            // check parameters...
1015            if (dataset == null) {
1016                throw new IllegalArgumentException("Null 'dataset' argument.");
1017            }
1018    
1019            // work out the minimum value...
1020            if (dataset instanceof RangeInfo) {
1021                RangeInfo info = (RangeInfo) dataset;
1022                return new Double(info.getRangeLowerBound(true));
1023            }
1024    
1025            // hasn't implemented RangeInfo, so we'll have to iterate...
1026            else {
1027                double minimum = Double.POSITIVE_INFINITY;
1028                int seriesCount = dataset.getRowCount();
1029                int itemCount = dataset.getColumnCount();
1030                for (int series = 0; series < seriesCount; series++) {
1031                    for (int item = 0; item < itemCount; item++) {
1032                        Number value;
1033                        if (dataset instanceof IntervalCategoryDataset) {
1034                            IntervalCategoryDataset icd 
1035                                = (IntervalCategoryDataset) dataset;
1036                            value = icd.getStartValue(series, item);
1037                        }
1038                        else {
1039                            value = dataset.getValue(series, item);
1040                        }
1041                        if (value != null) {
1042                            minimum = Math.min(minimum, value.doubleValue());
1043                        }
1044                    }
1045                }
1046                if (minimum == Double.POSITIVE_INFINITY) {
1047                    return null;
1048                }
1049                else {
1050                    return new Double(minimum);
1051                }
1052    
1053            }
1054    
1055        }
1056    
1057        /**
1058         * Returns the minimum range value for the specified dataset.  This is 
1059         * easy if the dataset implements the {@link RangeInfo} interface (a good
1060         * idea if there is an efficient way to determine the minimum value).  
1061         * Otherwise, it involves iterating over the entire data-set.  Returns 
1062         * <code>null</code> if all the data values in the dataset are 
1063         * <code>null</code>.
1064         *
1065         * @param dataset  the dataset (<code>null</code> not permitted).
1066         *
1067         * @return The minimum value (possibly <code>null</code>).
1068         */
1069        public static Number findMinimumRangeValue(XYDataset dataset) {
1070    
1071            if (dataset == null) {
1072                throw new IllegalArgumentException("Null 'dataset' argument.");
1073            }
1074    
1075            // work out the minimum value...
1076            if (dataset instanceof RangeInfo) {
1077                RangeInfo info = (RangeInfo) dataset;
1078                return new Double(info.getRangeLowerBound(true));
1079            }
1080    
1081            // hasn't implemented RangeInfo, so we'll have to iterate...
1082            else {
1083                double minimum = Double.POSITIVE_INFINITY;
1084                int seriesCount = dataset.getSeriesCount();
1085                for (int series = 0; series < seriesCount; series++) {
1086                    int itemCount = dataset.getItemCount(series);
1087                    for (int item = 0; item < itemCount; item++) {
1088    
1089                        double value;
1090                        if (dataset instanceof IntervalXYDataset) {
1091                            IntervalXYDataset intervalXYData 
1092                                = (IntervalXYDataset) dataset;
1093                            value = intervalXYData.getStartYValue(series, item);
1094                        }
1095                        else if (dataset instanceof OHLCDataset) {
1096                            OHLCDataset highLowData = (OHLCDataset) dataset;
1097                            value = highLowData.getLowValue(series, item);
1098                        }
1099                        else {
1100                            value = dataset.getYValue(series, item);
1101                        }
1102                        if (!Double.isNaN(value)) {
1103                            minimum = Math.min(minimum, value);
1104                        }
1105    
1106                    }
1107                }
1108                if (minimum == Double.POSITIVE_INFINITY) {
1109                    return null;
1110                }
1111                else {
1112                    return new Double(minimum);
1113                }
1114    
1115            }
1116    
1117        }
1118    
1119        /**
1120         * Returns the maximum range value for the specified dataset.  This is easy
1121         * if the dataset implements the {@link RangeInfo} interface (a good idea 
1122         * if there is an efficient way to determine the maximum value).  
1123         * Otherwise, it involves iterating over the entire data-set.  Returns 
1124         * <code>null</code> if all the data values are <code>null</code>.
1125         *
1126         * @param dataset  the dataset (<code>null</code> not permitted).
1127         *
1128         * @return The maximum value (possibly <code>null</code>).
1129         */
1130        public static Number findMaximumRangeValue(CategoryDataset dataset) {
1131    
1132            if (dataset == null) {
1133                throw new IllegalArgumentException("Null 'dataset' argument.");
1134            }
1135    
1136            // work out the minimum value...
1137            if (dataset instanceof RangeInfo) {
1138                RangeInfo info = (RangeInfo) dataset;
1139                return new Double(info.getRangeUpperBound(true));
1140            }
1141    
1142            // hasn't implemented RangeInfo, so we'll have to iterate...
1143            else {
1144    
1145                double maximum = Double.NEGATIVE_INFINITY;
1146                int seriesCount = dataset.getRowCount();
1147                int itemCount = dataset.getColumnCount();
1148                for (int series = 0; series < seriesCount; series++) {
1149                    for (int item = 0; item < itemCount; item++) {
1150                        Number value;
1151                        if (dataset instanceof IntervalCategoryDataset) {
1152                            IntervalCategoryDataset icd 
1153                                = (IntervalCategoryDataset) dataset;
1154                            value = icd.getEndValue(series, item);
1155                        }
1156                        else {
1157                            value = dataset.getValue(series, item);
1158                        }
1159                        if (value != null) {
1160                            maximum = Math.max(maximum, value.doubleValue());
1161                        }
1162                    }
1163                }
1164                if (maximum == Double.NEGATIVE_INFINITY) {
1165                    return null;
1166                }
1167                else {
1168                    return new Double(maximum);
1169                }
1170    
1171            }
1172    
1173        }
1174    
1175        /**
1176         * Returns the maximum range value for the specified dataset.  This is 
1177         * easy if the dataset implements the {@link RangeInfo} interface (a good 
1178         * idea if there is an efficient way to determine the maximum value).  
1179         * Otherwise, it involves iterating over the entire data-set.  Returns 
1180         * <code>null</code> if all the data values are <code>null</code>.
1181         *
1182         * @param dataset  the dataset (<code>null</code> not permitted).
1183         *
1184         * @return The maximum value (possibly <code>null</code>).
1185         */
1186        public static Number findMaximumRangeValue(XYDataset dataset) {
1187    
1188            if (dataset == null) {
1189                throw new IllegalArgumentException("Null 'dataset' argument.");
1190            }
1191    
1192            // work out the minimum value...
1193            if (dataset instanceof RangeInfo) {
1194                RangeInfo info = (RangeInfo) dataset;
1195                return new Double(info.getRangeUpperBound(true));
1196            }
1197    
1198            // hasn't implemented RangeInfo, so we'll have to iterate...
1199            else  {
1200    
1201                double maximum = Double.NEGATIVE_INFINITY;
1202                int seriesCount = dataset.getSeriesCount();
1203                for (int series = 0; series < seriesCount; series++) {
1204                    int itemCount = dataset.getItemCount(series);
1205                    for (int item = 0; item < itemCount; item++) {
1206                        double value;
1207                        if (dataset instanceof IntervalXYDataset) {
1208                            IntervalXYDataset intervalXYData 
1209                                = (IntervalXYDataset) dataset;
1210                            value = intervalXYData.getEndYValue(series, item);
1211                        }
1212                        else if (dataset instanceof OHLCDataset) {
1213                            OHLCDataset highLowData = (OHLCDataset) dataset;
1214                            value = highLowData.getHighValue(series, item);
1215                        }
1216                        else {
1217                            value = dataset.getYValue(series, item);
1218                        }
1219                        if (!Double.isNaN(value)) {
1220                            maximum = Math.max(maximum, value);
1221                        }
1222                    }
1223                }
1224                if (maximum == Double.NEGATIVE_INFINITY) {
1225                    return null;
1226                }
1227                else {
1228                    return new Double(maximum);
1229                }
1230    
1231            }
1232    
1233        }
1234    
1235        /**
1236         * Returns the minimum and maximum values for the dataset's range 
1237         * (y-values), assuming that the series in one category are stacked.
1238         *
1239         * @param dataset  the dataset (<code>null</code> not permitted).
1240         *
1241         * @return The range (<code>null</code> if the dataset contains no values).
1242         */
1243        public static Range findStackedRangeBounds(CategoryDataset dataset) {
1244            return findStackedRangeBounds(dataset, 0.0);
1245        }
1246    
1247        /**
1248         * Returns the minimum and maximum values for the dataset's range 
1249         * (y-values), assuming that the series in one category are stacked.
1250         *
1251         * @param dataset  the dataset (<code>null</code> not permitted).
1252         * @param base  the base value for the bars.
1253         *
1254         * @return The range (<code>null</code> if the dataset contains no values).
1255         */
1256        public static Range findStackedRangeBounds(CategoryDataset dataset, 
1257                double base) {
1258            if (dataset == null) {
1259                throw new IllegalArgumentException("Null 'dataset' argument.");
1260            }
1261            Range result = null;
1262            double minimum = Double.POSITIVE_INFINITY;
1263            double maximum = Double.NEGATIVE_INFINITY;
1264            int categoryCount = dataset.getColumnCount();
1265            for (int item = 0; item < categoryCount; item++) {
1266                double positive = base;
1267                double negative = base;
1268                int seriesCount = dataset.getRowCount();
1269                for (int series = 0; series < seriesCount; series++) {
1270                    Number number = dataset.getValue(series, item);
1271                    if (number != null) {
1272                        double value = number.doubleValue();
1273                        if (value > 0.0) {
1274                            positive = positive + value;
1275                        }
1276                        if (value < 0.0) {
1277                            negative = negative + value;  
1278                            // '+', remember value is negative
1279                        }
1280                    }
1281                }
1282                minimum = Math.min(minimum, negative);
1283                maximum = Math.max(maximum, positive);
1284            }
1285            if (minimum <= maximum) {
1286                result = new Range(minimum, maximum);
1287            }
1288            return result;
1289    
1290        }
1291    
1292        /**
1293         * Returns the minimum and maximum values for the dataset's range 
1294         * (y-values), assuming that the series in one category are stacked.
1295         *
1296         * @param dataset  the dataset.
1297         * @param map  a structure that maps series to groups.
1298         *
1299         * @return The value range (<code>null</code> if the dataset contains no 
1300         *         values).
1301         */
1302        public static Range findStackedRangeBounds(CategoryDataset dataset,
1303                                                   KeyToGroupMap map) {
1304        
1305            Range result = null;
1306            if (dataset != null) {
1307                
1308                // create an array holding the group indices...
1309                int[] groupIndex = new int[dataset.getRowCount()];
1310                for (int i = 0; i < dataset.getRowCount(); i++) {
1311                    groupIndex[i] = map.getGroupIndex(
1312                        map.getGroup(dataset.getRowKey(i))
1313                    );   
1314                }
1315                
1316                // minimum and maximum for each group...
1317                int groupCount = map.getGroupCount();
1318                double[] minimum = new double[groupCount];
1319                double[] maximum = new double[groupCount];
1320                
1321                int categoryCount = dataset.getColumnCount();
1322                for (int item = 0; item < categoryCount; item++) {
1323                    double[] positive = new double[groupCount];
1324                    double[] negative = new double[groupCount];
1325                    int seriesCount = dataset.getRowCount();
1326                    for (int series = 0; series < seriesCount; series++) {
1327                        Number number = dataset.getValue(series, item);
1328                        if (number != null) {
1329                            double value = number.doubleValue();
1330                            if (value > 0.0) {
1331                                positive[groupIndex[series]] 
1332                                     = positive[groupIndex[series]] + value;
1333                            }
1334                            if (value < 0.0) {
1335                                negative[groupIndex[series]] 
1336                                     = negative[groupIndex[series]] + value;
1337                                     // '+', remember value is negative
1338                            }
1339                        }
1340                    }
1341                    for (int g = 0; g < groupCount; g++) {
1342                        minimum[g] = Math.min(minimum[g], negative[g]);
1343                        maximum[g] = Math.max(maximum[g], positive[g]);
1344                    }
1345                }
1346                for (int j = 0; j < groupCount; j++) {
1347                    result = Range.combine(
1348                        result, new Range(minimum[j], maximum[j])