Java tutorial
/* =========================================================== * JFreeChart : a free chart library for the Java(tm) platform * =========================================================== * * (C) Copyright 2000-2017, by Object Refinery Limited and Contributors. * * Project Info: http://www.jfree.org/jfreechart/index.html * * This library is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation; either version 2.1 of the License, or * (at your option) any later version. * * This library is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public * License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, * USA. * * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. * Other names may be trademarks of their respective owners.] * * -------------- * DataUtils.java * -------------- * (C) Copyright 2003-2017, by Object Refinery Limited and contributors. * * Original Author: David Gilbert (for Object Refinery Limited); * Contributor(s): Peter Kolb (patch 2511330); * * Changes * ------- * 05-Mar-2003 : Version 1 (DG); * 03-Mar-2005 : Moved createNumberArray() and createNumberArray2D() methods * from the DatasetUtilities class (DG); * 17-May-2005 : Added calculateColumnTotal() and calculateRowTotal() * methods (DG); * 28-Jan-2009 : Added equal(double[][], double[][]) method (DG); * 28-Jan-2009 : Added clone(double[][]) method (DG); * 04-Feb-2009 : Added calculateColumnTotal/RowTotal variants (PK); * 03-Jul-2013 : Use ParamChecks (DG); * */ package org.jfree.data; import java.util.Arrays; import org.jfree.chart.util.Args; import org.jfree.data.general.DatasetUtils; /** * Utility methods for use with some of the data classes (but not the datasets, * see {@link DatasetUtils}). */ public abstract class DataUtils { /** * Tests two arrays for equality. To be considered equal, the arrays must * have exactly the same dimensions, and the values in each array must also * match (two values that qre both NaN or both INF are considered equal * in this test). * * @param a the first array ({@code null} permitted). * @param b the second array ({@code null} permitted). * * @return A boolean. * * @since 1.0.13 */ public static boolean equal(double[][] a, double[][] b) { if (a == null) { return (b == null); } if (b == null) { return false; // already know 'a' isn't null } if (a.length != b.length) { return false; } for (int i = 0; i < a.length; i++) { if (!Arrays.equals(a[i], b[i])) { return false; } } return true; } /** * Returns a clone of the specified array. * * @param source the source array ({@code null} not permitted). * * @return A clone of the array. * * @since 1.0.13 */ public static double[][] clone(double[][] source) { Args.nullNotPermitted(source, "source"); double[][] clone = new double[source.length][]; for (int i = 0; i < source.length; i++) { if (source[i] != null) { double[] row = new double[source[i].length]; System.arraycopy(source[i], 0, row, 0, source[i].length); clone[i] = row; } } return clone; } /** * Returns the total of the values in one column of the supplied data * table. * * @param data the table of values ({@code null} not permitted). * @param column the column index (zero-based). * * @return The total of the values in the specified column. */ public static double calculateColumnTotal(Values2D data, int column) { Args.nullNotPermitted(data, "data"); double total = 0.0; int rowCount = data.getRowCount(); for (int r = 0; r < rowCount; r++) { Number n = data.getValue(r, column); if (n != null) { total += n.doubleValue(); } } return total; } /** * Returns the total of the values in one column of the supplied data * table by taking only the row numbers in the array into account. * * @param data the table of values ({@code null} not permitted). * @param column the column index (zero-based). * @param validRows the array with valid rows (zero-based). * * @return The total of the valid values in the specified column. * * @since 1.0.13 */ public static double calculateColumnTotal(Values2D data, int column, int[] validRows) { Args.nullNotPermitted(data, "data"); double total = 0.0; int rowCount = data.getRowCount(); for (int v = 0; v < validRows.length; v++) { int row = validRows[v]; if (row < rowCount) { Number n = data.getValue(row, column); if (n != null) { total += n.doubleValue(); } } } return total; } /** * Returns the total of the values in one row of the supplied data * table. * * @param data the table of values ({@code null} not permitted). * @param row the row index (zero-based). * * @return The total of the values in the specified row. */ public static double calculateRowTotal(Values2D data, int row) { Args.nullNotPermitted(data, "data"); double total = 0.0; int columnCount = data.getColumnCount(); for (int c = 0; c < columnCount; c++) { Number n = data.getValue(row, c); if (n != null) { total += n.doubleValue(); } } return total; } /** * Returns the total of the values in one row of the supplied data * table by taking only the column numbers in the array into account. * * @param data the table of values ({@code null} not permitted). * @param row the row index (zero-based). * @param validCols the array with valid cols (zero-based). * * @return The total of the valid values in the specified row. * * @since 1.0.13 */ public static double calculateRowTotal(Values2D data, int row, int[] validCols) { Args.nullNotPermitted(data, "data"); double total = 0.0; int colCount = data.getColumnCount(); for (int v = 0; v < validCols.length; v++) { int col = validCols[v]; if (col < colCount) { Number n = data.getValue(row, col); if (n != null) { total += n.doubleValue(); } } } return total; } /** * Constructs an array of {@code Number} objects from an array of * {@code double} primitives. * * @param data the data ({@code null} not permitted). * * @return An array of {@code double}. */ public static Number[] createNumberArray(double[] data) { Args.nullNotPermitted(data, "data"); Number[] result = new Number[data.length]; for (int i = 0; i < data.length; i++) { result[i] = new Double(data[i]); } return result; } /** * Constructs an array of arrays of {@code Number} objects from a * corresponding structure containing {@code double} primitives. * * @param data the data ({@code null} not permitted). * * @return An array of {@code double}. */ public static Number[][] createNumberArray2D(double[][] data) { Args.nullNotPermitted(data, "data"); int l1 = data.length; Number[][] result = new Number[l1][]; for (int i = 0; i < l1; i++) { result[i] = createNumberArray(data[i]); } return result; } /** * Returns a {@link KeyedValues} instance that contains the cumulative * percentage values for the data in another {@link KeyedValues} instance. * <p> * The percentages are values between 0.0 and 1.0 (where 1.0 = 100%). * * @param data the data ({@code null} not permitted). * * @return The cumulative percentages. */ public static KeyedValues getCumulativePercentages(KeyedValues data) { Args.nullNotPermitted(data, "data"); DefaultKeyedValues result = new DefaultKeyedValues(); double total = 0.0; for (int i = 0; i < data.getItemCount(); i++) { Number v = data.getValue(i); if (v != null) { total = total + v.doubleValue(); } } double runningTotal = 0.0; for (int i = 0; i < data.getItemCount(); i++) { Number v = data.getValue(i); if (v != null) { runningTotal = runningTotal + v.doubleValue(); } result.addValue(data.getKey(i), new Double(runningTotal / total)); } return result; } }