datasetutilities.java

java图形利器

                return new Double(maximum);
            }

        }

    }

    /**
     * Returns the maximum range value for the specified dataset.  This is 
     * easy if the dataset implements the {@link RangeInfo} interface (a good 
     * idea if there is an efficient way to determine the maximum value).  
     * Otherwise, it involves iterating over the entire data-set.  Returns 
     * <code>null</code> if all the data values are <code>null</code>.
     *
     * @param dataset  the dataset (<code>null</code> not permitted).
     *
     * @return The maximum value (possibly <code>null</code>).
     */
    public static Number findMaximumRangeValue(XYDataset dataset) {

        if (dataset == null) {
            throw new IllegalArgumentException("Null 'dataset' argument.");
        }

        // work out the minimum value...
        if (dataset instanceof RangeInfo) {
            RangeInfo info = (RangeInfo) dataset;
            return new Double(info.getRangeUpperBound(true));
        }

        // hasn't implemented RangeInfo, so we'll have to iterate...
        else  {

            double maximum = Double.NEGATIVE_INFINITY;
            int seriesCount = dataset.getSeriesCount();
            for (int series = 0; series < seriesCount; series++) {
                int itemCount = dataset.getItemCount(series);
                for (int item = 0; item < itemCount; item++) {
                    double value;
                    if (dataset instanceof IntervalXYDataset) {
                        IntervalXYDataset intervalXYData 
                            = (IntervalXYDataset) dataset;
                        value = intervalXYData.getEndYValue(series, item);
                    }
                    else if (dataset instanceof OHLCDataset) {
                        OHLCDataset highLowData = (OHLCDataset) dataset;
                        value = highLowData.getHighValue(series, item);
                    }
                    else {
                        value = dataset.getYValue(series, item);
                    }
                    if (!Double.isNaN(value)) {
                        maximum = Math.max(maximum, value);
                    }
                }
            }
            if (maximum == Double.NEGATIVE_INFINITY) {
                return null;
            }
            else {
                return new Double(maximum);
            }

        }

    }

    /**
     * Returns the minimum and maximum values for the dataset's range 
     * (y-values), assuming that the series in one category are stacked.
     *
     * @param dataset  the dataset (<code>null</code> not permitted).
     *
     * @return The range (<code>null</code> if the dataset contains no values).
     */
    public static Range findStackedRangeBounds(CategoryDataset dataset) {
        return findStackedRangeBounds(dataset, 0.0);
    }

    /**
     * Returns the minimum and maximum values for the dataset's range 
     * (y-values), assuming that the series in one category are stacked.
     *
     * @param dataset  the dataset (<code>null</code> not permitted).
     * @param base  the base value for the bars.
     *
     * @return The range (<code>null</code> if the dataset contains no values).
     */
    public static Range findStackedRangeBounds(CategoryDataset dataset, 
            double base) {
        if (dataset == null) {
            throw new IllegalArgumentException("Null 'dataset' argument.");
        }
        Range result = null;
        double minimum = Double.POSITIVE_INFINITY;
        double maximum = Double.NEGATIVE_INFINITY;
        int categoryCount = dataset.getColumnCount();
        for (int item = 0; item < categoryCount; item++) {
            double positive = base;
            double negative = base;
            int seriesCount = dataset.getRowCount();
            for (int series = 0; series < seriesCount; series++) {
                Number number = dataset.getValue(series, item);
                if (number != null) {
                    double value = number.doubleValue();
                    if (value > 0.0) {
                        positive = positive + value;
                    }
                    if (value < 0.0) {
                        negative = negative + value;  
                        // '+', remember value is negative
                    }
                }
            }
            minimum = Math.min(minimum, negative);
            maximum = Math.max(maximum, positive);
        }
        if (minimum <= maximum) {
            result = new Range(minimum, maximum);
        }
        return result;

    }

    /**
     * Returns the minimum and maximum values for the dataset's range 
     * (y-values), assuming that the series in one category are stacked.
     *
     * @param dataset  the dataset.
     * @param map  a structure that maps series to groups.
     *
     * @return The value range (<code>null</code> if the dataset contains no 
     *         values).
     */
    public static Range findStackedRangeBounds(CategoryDataset dataset,
                                               KeyToGroupMap map) {
    
        Range result = null;
        if (dataset != null) {
            
            // create an array holding the group indices...
            int[] groupIndex = new int[dataset.getRowCount()];
            for (int i = 0; i < dataset.getRowCount(); i++) {
                groupIndex[i] = map.getGroupIndex(
                    map.getGroup(dataset.getRowKey(i))
                );   
            }
            
            // minimum and maximum for each group...
            int groupCount = map.getGroupCount();
            double[] minimum = new double[groupCount];
            double[] maximum = new double[groupCount];
            
            int categoryCount = dataset.getColumnCount();
            for (int item = 0; item < categoryCount; item++) {
                double[] positive = new double[groupCount];
                double[] negative = new double[groupCount];
                int seriesCount = dataset.getRowCount();
                for (int series = 0; series < seriesCount; series++) {
                    Number number = dataset.getValue(series, item);
                    if (number != null) {
                        double value = number.doubleValue();
                        if (value > 0.0) {
                            positive[groupIndex[series]] 
                                 = positive[groupIndex[series]] + value;
                        }
                        if (value < 0.0) {
                            negative[groupIndex[series]] 
                                 = negative[groupIndex[series]] + value;
                                 // '+', remember value is negative
                        }
                    }
                }
                for (int g = 0; g < groupCount; g++) {
                    minimum[g] = Math.min(minimum[g], negative[g]);
                    maximum[g] = Math.max(maximum[g], positive[g]);
                }
            }
            for (int j = 0; j < groupCount; j++) {
                result = Range.combine(
                    result, new Range(minimum[j], maximum[j])
                );
            }
        }
        return result;

    }

    /**
     * Returns the minimum value in the dataset range, assuming that values in
     * each category are "stacked".
     *
     * @param dataset  the dataset.
     *
     * @return The minimum value.
     */
    public static Number findMinimumStackedRangeValue(CategoryDataset dataset) {

        Number result = null;
        if (dataset != null) {
            double minimum = 0.0;
            int categoryCount = dataset.getRowCount();
            for (int item = 0; item < categoryCount; item++) {
                double total = 0.0;

                int seriesCount = dataset.getColumnCount();
                for (int series = 0; series < seriesCount; series++) {
                    Number number = dataset.getValue(series, item);
                    if (number != null) {
                        double value = number.doubleValue();
                        if (value < 0.0) {
                            total = total + value;  
                            // '+', remember value is negative
                        }
                    }
                }
                minimum = Math.min(minimum, total);

            }
            result = new Double(minimum);
        }
        return result;

    }

    /**
     * Returns the maximum value in the dataset range, assuming that values in
     * each category are "stacked".
     *
     * @param dataset  the dataset (<code>null</code> permitted).
     *
     * @return The maximum value (possibly <code>null</code>).
     */
    public static Number findMaximumStackedRangeValue(CategoryDataset dataset) {

        Number result = null;

        if (dataset != null) {
            double maximum = 0.0;
            int categoryCount = dataset.getColumnCount();
            for (int item = 0; item < categoryCount; item++) {
                double total = 0.0;
                int seriesCount = dataset.getRowCount();
                for (int series = 0; series < seriesCount; series++) {
                    Number number = dataset.getValue(series, item);
                    if (number != null) {
                        double value = number.doubleValue();
                        if (value > 0.0) {
                            total = total + value;
                        }
                    }
                }
                maximum = Math.max(maximum, total);
            }
            result = new Double(maximum);
        }

        return result;

    }

    /**
     * Returns the minimum and maximum values for the dataset's range,
     * assuming that the series are stacked.
     *
     * @param dataset  the dataset (<code>null</code> not permitted).
     * 
     * @return The range ([0.0, 0.0] if the dataset contains no values).
     */
    public static Range findStackedRangeBounds(TableXYDataset dataset) {
        return findStackedRangeBounds(dataset, 0.0);
    }
    
    /**
     * Returns the minimum and maximum values for the dataset's range,
     * assuming that the series are stacked, using the specified base value.
     *
     * @param dataset  the dataset (<code>null</code> not permitted).
     * @param base  the base value.
     * 
     * @return The range (<code>null</code> if the dataset contains no values).
     */
    public static Range findStackedRangeBounds(TableXYDataset dataset, 
                                               double base) {
        if (dataset == null) {
            throw new IllegalArgumentException("Null 'dataset' argument.");
        }
        double minimum = base;
        double maximum = base;
        for (int itemNo = 0; itemNo < dataset.getItemCount(); itemNo++) {
            double positive = base;
            double negative = base;
            int seriesCount = dataset.getSeriesCount();
            for (int seriesNo = 0; seriesNo < seriesCount; seriesNo++) {
                double y = dataset.getYValue(seriesNo, itemNo);
                if (!Double.isNaN(y)) {
                    if (y > 0.0) {
                        positive += y;
                    }
                    else {
                        negative += y;
                    }
                }
            }
            if (positive > maximum) {
                maximum = positive;
            } 
            if (negative < minimum) {
                minimum = negative;
            } 
        }
        if (minimum <= maximum) {
            return new Range(minimum, maximum);
        }
        else {
            return null;   
        }
    }
    
    /**
     * Calculates the total for the y-values in all series for a given item
     * index.
     * 
     * @param dataset  the dataset.
     * @param item  the item index.
     * 
     * @return The total.
     * 
     * @since 1.0.5
     */
    public static double calculateStackTotal(TableXYDataset dataset, int item) {
        double total = 0.0;
        int seriesCount = dataset.getSeriesCount();
        for (int s = 0; s < seriesCount; s++) {
            double value = dataset.getYValue(s, item);
            if (!Double.isNaN(value)) {
                total = total + value;
            }
        }
        return total;
    }

    /**
     * Calculates the range of values for a dataset where each item is the 
     * running total of the items for the current series.
     * 
     * @param dataset  the dataset (<code>null</code> not permitted).
     * 
     * @return The range.
     * 
     * @see #findRangeBounds(CategoryDataset)
     */
    public static Range findCumulativeRangeBounds(CategoryDataset dataset) {
        
        if (dataset == null) {
            throw new IllegalArgumentException("Null 'dataset' argument.");
        }
        
        boolean allItemsNull = true; // we'll set this to false if there is at 
                                     // least one non-null data item... 
        double minimum = 0.0;
        double maximum = 0.0;
        for (int row = 0; row < dataset.getRowCount(); row++) {
            double runningTotal = 0.0;
            for (int column = 0; column < dataset.getColumnCount() - 1; 
                 column++) {
                Number n = dataset.getValue(row, column);
                if (n != null) {
                    allItemsNull = false;
                    double value = n.doubleValue();
                    runningTotal = runningTotal + value;
                    minimum = Math.min(minimum, runningTotal);
                    maximum = Math.max(maximum, runningTotal);
                }
            }    
        }
        if (!allItemsNull) {
            return new Range(minimum, maximum);
        }
        else {
            return null;
        }
        
    }

}