datasetutilities.java

java图形利器

     * Creates a {@link CategoryDataset} that contains a copy of the data in 
     * an array (instances of <code>Double</code> are created to represent the 
     * data items).
     * <p>
     * Row and column keys are taken from the supplied arrays.
     *
     * @param rowKeys  the row keys (<code>null</code> not permitted).
     * @param columnKeys  the column keys (<code>null</code> not permitted).
     * @param data  the data.
     *
     * @return The dataset.
     */
    public static CategoryDataset createCategoryDataset(Comparable[] rowKeys,
                                                        Comparable[] columnKeys,
                                                        double[][] data) {

        // check arguments...
        if (rowKeys == null) {
            throw new IllegalArgumentException("Null 'rowKeys' argument.");
        }
        if (columnKeys == null) {
            throw new IllegalArgumentException("Null 'columnKeys' argument.");
        }
        if (ArrayUtilities.hasDuplicateItems(rowKeys)) {
            throw new IllegalArgumentException("Duplicate items in 'rowKeys'.");
        }
        if (ArrayUtilities.hasDuplicateItems(columnKeys)) {
            throw new IllegalArgumentException(
                "Duplicate items in 'columnKeys'."
            );
        }
        if (rowKeys.length != data.length) {
            throw new IllegalArgumentException(
                "The number of row keys does not match the number of rows in "
                + "the data array."
            );
        }
        int columnCount = 0;
        for (int r = 0; r < data.length; r++) {
            columnCount = Math.max(columnCount, data[r].length);
        }
        if (columnKeys.length != columnCount) {
            throw new IllegalArgumentException(
                "The number of column keys does not match the number of "
                + "columns in the data array."
            );
        }
        
        // now do the work...
        DefaultCategoryDataset result = new DefaultCategoryDataset();
        for (int r = 0; r < data.length; r++) {
            Comparable rowKey = rowKeys[r];
            for (int c = 0; c < data[r].length; c++) {
                Comparable columnKey = columnKeys[c];
                result.addValue(new Double(data[r][c]), rowKey, columnKey);
            }
        }
        return result;

    }

    /**
     * Creates a {@link CategoryDataset} by copying the data from the supplied 
     * {@link KeyedValues} instance.
     *
     * @param rowKey  the row key (<code>null</code> not permitted).
     * @param rowData  the row data (<code>null</code> not permitted).
     *
     * @return A dataset.
     */
    public static CategoryDataset createCategoryDataset(Comparable rowKey, 
                                                        KeyedValues rowData) {

        if (rowKey == null) {
            throw new IllegalArgumentException("Null 'rowKey' argument.");
        }
        if (rowData == null) {
            throw new IllegalArgumentException("Null 'rowData' argument.");
        }
        DefaultCategoryDataset result = new DefaultCategoryDataset();
        for (int i = 0; i < rowData.getItemCount(); i++) {
            result.addValue(rowData.getValue(i), rowKey, rowData.getKey(i));
        }
        return result;

    }

    /**
     * Creates an {@link XYDataset} by sampling the specified function over a 
     * fixed range.
     *
     * @param f  the function (<code>null</code> not permitted).
     * @param start  the start value for the range.
     * @param end  the end value for the range.
     * @param samples  the number of sample points (must be > 1).
     * @param seriesKey  the key to give the resulting series 
     *                   (<code>null</code> not permitted).
     *
     * @return A dataset.
     */
    public static XYDataset sampleFunction2D(Function2D f, 
                                             double start, 
                                             double end, 
                                             int samples,
                                             Comparable seriesKey) {

        if (f == null) {
            throw new IllegalArgumentException("Null 'f' argument.");   
        }
        if (seriesKey == null) {
            throw new IllegalArgumentException("Null 'seriesKey' argument.");
        }
        if (start >= end) {
            throw new IllegalArgumentException("Requires 'start' < 'end'.");
        }
        if (samples < 2) {
            throw new IllegalArgumentException("Requires 'samples' > 1");
        }

        XYSeries series = new XYSeries(seriesKey);
        double step = (end - start) / samples;
        for (int i = 0; i <= samples; i++) {
            double x = start + (step * i);
            series.add(x, f.getValue(x));
        }
        XYSeriesCollection collection = new XYSeriesCollection(series);
        return collection;

    }

    /**
     * Returns <code>true</code> if the dataset is empty (or <code>null</code>),
     * and <code>false</code> otherwise.
     *
     * @param dataset  the dataset (<code>null</code> permitted).
     *
     * @return A boolean.
     */
    public static boolean isEmptyOrNull(PieDataset dataset) {

        if (dataset == null) {
            return true;
        }

        int itemCount = dataset.getItemCount();
        if (itemCount == 0) {
            return true;
        }

        for (int item = 0; item < itemCount; item++) {
            Number y = dataset.getValue(item);
            if (y != null) {
                double yy = y.doubleValue();
                if (yy > 0.0) {
                    return false;
                }
            }
        }

        return true;

    }

    /**
     * Returns <code>true</code> if the dataset is empty (or <code>null</code>),
     * and <code>false</code> otherwise.
     *
     * @param dataset  the dataset (<code>null</code> permitted).
     *
     * @return A boolean.
     */
    public static boolean isEmptyOrNull(CategoryDataset dataset) {

        if (dataset == null) {
            return true;
        }

        int rowCount = dataset.getRowCount();
        int columnCount = dataset.getColumnCount();
        if (rowCount == 0 || columnCount == 0) {
            return true;
        }

        for (int r = 0; r < rowCount; r++) {
            for (int c = 0; c < columnCount; c++) {
                if (dataset.getValue(r, c) != null) {
                    return false;
                }

            }
        }

        return true;

    }

    /**
     * Returns <code>true</code> if the dataset is empty (or <code>null</code>),
     * and <code>false</code> otherwise.
     *
     * @param dataset  the dataset (<code>null</code> permitted).
     *
     * @return A boolean.
     */
    public static boolean isEmptyOrNull(XYDataset dataset) {

        boolean result = true;

        if (dataset != null) {
            for (int s = 0; s < dataset.getSeriesCount(); s++) {
                if (dataset.getItemCount(s) > 0) {
                    result = false;
                    continue;
                }
            }
        }

        return result;

    }

    /**
     * Returns the range of values in the domain (x-values) of a dataset.
     *
     * @param dataset  the dataset (<code>null</code> not permitted).
     *
     * @return The range of values (possibly <code>null</code>).
     */
    public static Range findDomainBounds(XYDataset dataset) {
        return findDomainBounds(dataset, true);
    }

    /**
     * Returns the range of values in the domain (x-values) of a dataset.
     *
     * @param dataset  the dataset (<code>null</code> not permitted).
     * @param includeInterval  determines whether or not the x-interval is taken
     *                         into account (only applies if the dataset is an
     *                         {@link IntervalXYDataset}).
     *
     * @return The range of values (possibly <code>null</code>).
     */
    public static Range findDomainBounds(XYDataset dataset, 
                                         boolean includeInterval) {

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

        Range result = null;
        // if the dataset implements DomainInfo, life is easier
        if (dataset instanceof DomainInfo) {
            DomainInfo info = (DomainInfo) dataset;
            result = info.getDomainBounds(includeInterval);
        }
        else {
            result = iterateDomainBounds(dataset, includeInterval);
        }
        return result;
        
    }

    /**
     * Iterates over the items in an {@link XYDataset} to find
     * the range of x-values. 
     *  
     * @param dataset  the dataset (<code>null</code> not permitted).
     * 
     * @return The range (possibly <code>null</code>).
     */
    public static Range iterateDomainBounds(XYDataset dataset) {
        return iterateDomainBounds(dataset, true);
    }

    /**
     * Iterates over the items in an {@link XYDataset} to find
     * the range of x-values. 
     *  
     * @param dataset  the dataset (<code>null</code> not permitted).
     * @param includeInterval  a flag that determines, for an IntervalXYDataset,
     *                         whether the x-interval or just the x-value is 
     *                         used to determine the overall range.
     *   
     * @return The range (possibly <code>null</code>).
     */
    public static Range iterateDomainBounds(XYDataset dataset, 
                                            boolean includeInterval) {
        if (dataset == null) {
            throw new IllegalArgumentException("Null 'dataset' argument.");   
        }
        double minimum = Double.POSITIVE_INFINITY;
        double maximum = Double.NEGATIVE_INFINITY;
        int seriesCount = dataset.getSeriesCount();
        double lvalue;
        double uvalue;
        if (includeInterval && dataset instanceof IntervalXYDataset) {
            IntervalXYDataset intervalXYData = (IntervalXYDataset) dataset;
            for (int series = 0; series < seriesCount; series++) {
                int itemCount = dataset.getItemCount(series);
                for (int item = 0; item < itemCount; item++) {
                    lvalue = intervalXYData.getStartXValue(series, item);
                    uvalue = intervalXYData.getEndXValue(series, item);
                    minimum = Math.min(minimum, lvalue);
                    maximum = Math.max(maximum, uvalue);
                }
            }
        }
        else {
            for (int series = 0; series < seriesCount; series++) {
                int itemCount = dataset.getItemCount(series);
                for (int item = 0; item < itemCount; item++) {
                    lvalue = dataset.getXValue(series, item);
                    uvalue = lvalue;
                    minimum = Math.min(minimum, lvalue);
                    maximum = Math.max(maximum, uvalue);
                }
            }
        }
        if (minimum > maximum) {
            return null;
        }
        else {
            return new Range(minimum, maximum);
        }
    }
    
    /**
     * Returns the range of values in the range for the dataset.
     *
     * @param dataset  the dataset (<code>null</code> not permitted).
     *
     * @return The range (possibly <code>null</code>).
     */
    public static Range findRangeBounds(CategoryDataset dataset) {
        return findRangeBounds(dataset, true);
    }
    
    /**
     * Returns the range of values in the range for the dataset.
     *
     * @param dataset  the dataset (<code>null</code> not permitted).
     * @param includeInterval  a flag that determines whether or not the
     *                         y-interval is taken into account.
     * 
     * @return The range (possibly <code>null</code>).
     */
    public static Range findRangeBounds(CategoryDataset dataset, 
                                        boolean includeInterval) {
        if (dataset == null) {
            throw new IllegalArgumentException("Null 'dataset' argument.");
        }
        Range result = null;
        if (dataset instanceof RangeInfo) {
            RangeInfo info = (RangeInfo) dataset;
            result = info.getRangeBounds(includeInterval);
        }
        else {
            result = iterateCategoryRangeBounds(dataset, includeInterval);
        }
        return result;
    }
    
    /**
     * Returns the range of values in the range for the dataset.  This method
     * is the partner for the {@link #findDomainBounds(XYDataset)} method.
     *
     * @param dataset  the dataset (<code>null</code> not permitted).
     *
     * @return The range (possibly <code>null</code>).
     */
    public static Range findRangeBounds(XYDataset dataset) {
        return findRangeBounds(dataset, true);
    }
    
    /**
     * Returns the range of values in the range for the dataset.  This method
     * is the partner for the {@link #findDomainBounds(XYDataset)} method.
     *
     * @param dataset  the dataset (<code>null</code> not permitted).
     * @param includeInterval  a flag that determines whether or not the
     *                         y-interval is taken into account.
     * 
     *
     * @return The range (possibly <code>null</code>).
     */
    public static Range findRangeBounds(XYDataset dataset, 
                                        boolean includeInterval) {
        if (dataset == null) {
            throw new IllegalArgumentException("Null 'dataset' argument.");