1 /* 2 * [The "BSD licence"] 3 * Copyright (c) 2005-2008 Terence Parr 4 * All rights reserved. 5 * 6 * Conversion to C#: 7 * Copyright (c) 2008-2009 Sam Harwell, Pixel Mine, Inc. 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 namespace Antlr.Runtime.Misc { 34 using System.Collections.Generic; 35 using Antlr.Runtime.JavaExtensions; 36 37 using Math = System.Math; 38 39 /** <summary>Stats routines needed by profiler etc...</summary> 40 * 41 * <remarks> 42 * note that these routines return 0.0 if no values exist in the X[] 43 * which is not "correct", but it is useful so I don't generate NaN 44 * in my output 45 * </remarks> 46 */ 47 public class Stats { 48 public const string ANTLRWORKS_DIR = "antlrworks"; 49 50 /** <summary>Compute the sample (unbiased estimator) standard deviation following:</summary> 51 * 52 * <remarks> 53 * Computing Deviations: Standard Accuracy 54 * Tony F. Chan and John Gregg Lewis 55 * Stanford University 56 * Communications of ACM September 1979 of Volume 22 the ACM Number 9 57 * 58 * The "two-pass" method from the paper; supposed to have better 59 * numerical properties than the textbook summation/sqrt. To me 60 * this looks like the textbook method, but I ain't no numerical 61 * methods guy. 62 * </remarks> 63 */ Stddev(int[] X)64 public static double Stddev(int[] X) { 65 int m = X.Length; 66 if (m <= 1) { 67 return 0; 68 } 69 double xbar = EnumerableExtensions.Average(X); 70 double s2 = 0.0; 71 for (int i = 0; i < m; i++) { 72 s2 += (X[i] - xbar) * (X[i] - xbar); 73 } 74 s2 = s2 / (m - 1); 75 return Math.Sqrt(s2); 76 } Stddev(List<int> X)77 public static double Stddev(List<int> X) { 78 int m = X.Count; 79 if (m <= 1) { 80 return 0; 81 } 82 double xbar = EnumerableExtensions.Average(X); 83 double s2 = 0.0; 84 for (int i = 0; i < m; i++) { 85 s2 += (X[i] - xbar) * (X[i] - xbar); 86 } 87 s2 = s2 / (m - 1); 88 return Math.Sqrt(s2); 89 } 90 91 #if DEBUG 92 /** <summary>Compute the sample mean</summary> */ 93 [System.Obsolete] avg(int[] X)94 public static double avg(int[] X) { 95 return EnumerableExtensions.Average(EnumerableExtensions.DefaultIfEmpty(X, 0)); 96 } 97 98 [System.Obsolete] min(int[] X)99 public static int min(int[] X) { 100 return EnumerableExtensions.Min(EnumerableExtensions.DefaultIfEmpty(X, int.MaxValue)); 101 } 102 103 [System.Obsolete] max(int[] X)104 public static int max(int[] X) { 105 return EnumerableExtensions.Max(EnumerableExtensions.DefaultIfEmpty(X, int.MinValue)); 106 } 107 108 [System.Obsolete] sum(int[] X)109 public static int sum(int[] X) { 110 return EnumerableExtensions.Sum(X); 111 } 112 #endif 113 WriteReport(string filename, string data)114 public static void WriteReport(string filename, string data) { 115 string absoluteFilename = GetAbsoluteFileName(filename); 116 117 System.IO.Directory.CreateDirectory(System.IO.Path.GetDirectoryName(absoluteFilename)); 118 System.IO.File.AppendAllText(absoluteFilename, data); 119 } 120 GetAbsoluteFileName(string filename)121 public static string GetAbsoluteFileName(string filename) { 122 string personalFolder = System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal); 123 return personalFolder + System.IO.Path.DirectorySeparatorChar + 124 ANTLRWORKS_DIR + System.IO.Path.DirectorySeparatorChar + 125 filename; 126 } 127 } 128 } 129