| /* |
| * [The "BSD licence"] |
| * Copyright (c) 2005-2008 Terence Parr |
| * All rights reserved. |
| * |
| * Conversion to C#: |
| * Copyright (c) 2008-2009 Sam Harwell, Pixel Mine, Inc. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| namespace Antlr.Runtime.Misc |
| { |
| using System.Collections.Generic; |
| |
| using Directory = System.IO.Directory; |
| using Environment = System.Environment; |
| using File = System.IO.File; |
| using Math = System.Math; |
| using Path = System.IO.Path; |
| |
| /** <summary>Stats routines needed by profiler etc...</summary> |
| * |
| * <remarks> |
| * note that these routines return 0.0 if no values exist in the X[] |
| * which is not "correct", but it is useful so I don't generate NaN |
| * in my output |
| * </remarks> |
| */ |
| public class Stats |
| { |
| public const string ANTLRWORKS_DIR = "antlrworks"; |
| |
| /** <summary>Compute the sample (unbiased estimator) standard deviation following:</summary> |
| * |
| * <remarks> |
| * Computing Deviations: Standard Accuracy |
| * Tony F. Chan and John Gregg Lewis |
| * Stanford University |
| * Communications of ACM September 1979 of Volume 22 the ACM Number 9 |
| * |
| * The "two-pass" method from the paper; supposed to have better |
| * numerical properties than the textbook summation/sqrt. To me |
| * this looks like the textbook method, but I ain't no numerical |
| * methods guy. |
| * </remarks> |
| */ |
| public static double Stddev( int[] X ) |
| { |
| int m = X.Length; |
| if ( m <= 1 ) |
| { |
| return 0; |
| } |
| double xbar = Average(X); |
| double s2 = 0.0; |
| for ( int i = 0; i < m; i++ ) |
| { |
| s2 += ( X[i] - xbar ) * ( X[i] - xbar ); |
| } |
| s2 = s2 / ( m - 1 ); |
| return Math.Sqrt( s2 ); |
| } |
| public static double Stddev( List<int> X ) |
| { |
| int m = X.Count; |
| if ( m <= 1 ) |
| { |
| return 0; |
| } |
| double xbar = Average(X); |
| double s2 = 0.0; |
| for ( int i = 0; i < m; i++ ) |
| { |
| s2 += ( X[i] - xbar ) * ( X[i] - xbar ); |
| } |
| s2 = s2 / ( m - 1 ); |
| return Math.Sqrt( s2 ); |
| } |
| |
| /** <summary>Compute the sample mean</summary> */ |
| public static double Average(ICollection<int> X) |
| { |
| if (X.Count == 0) |
| return 0.0; |
| |
| double sum = 0.0; |
| foreach (int i in X) |
| sum += i; |
| |
| return sum / X.Count; |
| } |
| |
| public static void WriteReport( string filename, string data ) |
| { |
| string absoluteFilename = GetAbsoluteFileName( filename ); |
| |
| Directory.CreateDirectory( Path.GetDirectoryName( absoluteFilename ) ); |
| File.AppendAllText( absoluteFilename, data ); |
| } |
| |
| public static string GetAbsoluteFileName( string filename ) |
| { |
| string personalFolder = Environment.GetFolderPath( Environment.SpecialFolder.Personal ); |
| return personalFolder + Path.DirectorySeparatorChar + |
| ANTLRWORKS_DIR + Path.DirectorySeparatorChar + |
| filename; |
| } |
| } |
| } |