nlpsolver/ThirdParty/EvolutionarySolver/src/net/adaptivebox/global/RandomGenerator.java

   1 /**
   2  * Description: For generating random numbers.
   3  *
   4  * @ Author        Create/Modi     Note
   5  * Xiaofeng Xie    Feb 22, 2001
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * Please acknowledge the author(s) if you use this code in any way.
  18  *
  19  * @version 1.0
  20  * @Since MAOS1.0
  21  */
  22
  23 package net.adaptivebox.global;
  24
  25 public class RandomGenerator {
  26
  27 /**This function returns a random integer number between the lowLimit and upLimit.
  28  * @param lowLimit lower limits
  29  *        upLimit The upper limits (between which the random number is to be generated)
  30  * @return int return value
  31  * Example: for find [0,1,2]
  32 */
  33 public static int intRangeRandom(int lowLimit,int upLimit){
  34 //  int num = (int)Math.rint(doubleRangeRandom(lowLimit,upLimit));
  35   int num = (int)Math.floor(doubleRangeRandom(lowLimit,upLimit+1)-1E-10);
  36   return(num);
  37 }
  38
  39 /**This function returns a random float number between the lowLimit and upLimit.
  40  * @param lowLimit lower limits
  41  *        upLimit The upper limits (between which the random number is to be generated)
  42  * @return double return value
  43 */
  44 public static double doubleRangeRandom(double lowLimit,double upLimit){
  45   double num = lowLimit + Math.random()*(upLimit-lowLimit);
  46   return(num);
  47 }
  48
  49 /**This function returns true or false with a random probability.
  50  * @return int return value
  51   */
  52   public static boolean booleanRandom(){
  53     boolean value = true;
  54     double temp=Math.random();
  55     if (temp<0.5) value=false;
  56     return value;
  57   }
  58
  59   public static int[] randomSelection(boolean[] types, int times) {
  60     int validNum = 0;
  61     for(int i=0; i<types.length; i++) {
  62       if(!types[i]) {
  63         validNum++;
  64       }
  65     }
  66     int[] totalIndices = new int[validNum];
  67     validNum = 0;
  68     for(int i=0; i<types.length; i++) {
  69       if(!types[i]) {
  70         totalIndices[validNum] = i;
  71         validNum++;
  72         if(validNum==totalIndices.length) break;
  73       }
  74     }
  75     return randomSelection(totalIndices, times);
  76   }
  77
  78 //  public static int[] randomSelection(boolean[] types, int times) {
  79 //    int realTimes = times;
  80 //    if(realTimes>types.length) realTimes = types.length;
  81 //    boolean[] internalTypes = (boolean[])types.clone();
  82 //    int upper = types.length-1;
  83 //    int[] indices = new int[realTimes];
  84 //    if(realTimes==types.length) {
  85 //      for(int i=0; i<indices.length; i++) {
  86 //        indices[i] = i;
  87 //      }
  88 //      return indices;
  89 //    }
  90 //    int i = 0;
  91 //    while(i<realTimes) {
  92 //      indices[i] = intRangeRandom(0, upper);
  93 //      if(!internalTypes[indices[i]]) {
  94 //        internalTypes[indices[i]] = true;
  95 //        i++;
  96 //      }
  97 //    }
  98 //    return indices;
  99 //  }
 100
 101   public static int[] randomSelection(int low, int up, int times){
 102     int[] totalIndices = new int[up-low];
 103     for (int i=low; i<up; i++) {
 104       totalIndices[i] = i;
 105     }
 106     return randomSelection(totalIndices, times);
 107   }
 108
 109   public static int getRealV(double randTypeV) {
 110     if(randTypeV<=0) return 0;
 111     int realV = (int)Math.ceil(randTypeV);
 112     if(Math.random()<(randTypeV-realV)) realV++;
 113     return realV;
 114   }
 115
 116   public static int[] randomSelection(int[] totalIndices, int times) {
 117     if (times>=totalIndices.length) {
 118       return totalIndices;
 119     }
 120     int[] indices = randomSelection(totalIndices.length, times);
 121     for(int i=0; i<indices.length; i++) {
 122       indices[i] = totalIndices[indices[i]];
 123     }
 124     return indices;
 125   }
 126
 127   public static int[] randomSelection(int maxNum, int times) {
 128     if(times<=0) return new int[0];
 129     int realTimes = Math.min(maxNum, times);
 130     boolean[] flags = new boolean[maxNum];
 131 //    Arrays.fill(flags, false);
 132     boolean isBelowHalf = times<maxNum*0.5;
 133     int virtualTimes = realTimes;
 134     if(!isBelowHalf) {
 135       virtualTimes = maxNum-realTimes;
 136     }
 137     int i = 0;
 138     int upper = maxNum-1;
 139     int[] indices = new int[realTimes];
 140
 141     while(i<virtualTimes) {
 142       indices[i] = intRangeRandom(0, upper);
 143       if(!flags[indices[i]]) {
 144         flags[indices[i]] = true;
 145         i++;
 146       }
 147     }
 148     if(!isBelowHalf) {
 149       int j=0;
 150       for(i=0; i<maxNum; i++) {
 151         if(flags[i]==isBelowHalf) {
 152           indices[j] = i;
 153           j++;
 154           if(j==realTimes) break;
 155         }
 156       }
 157     }
 158     return indices;
 159   }
 160 }