1 files changed, 108 insertions, 0 deletions
diff --git a/nlpsolver/ThirdParty/EvolutionarySolver/src/net/adaptivebox/global/RandomGenerator.java b/nlpsolver/ThirdParty/EvolutionarySolver/src/net/adaptivebox/global/RandomGenerator.java
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index 000000000..245149e87
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+++ b/nlpsolver/ThirdParty/EvolutionarySolver/src/net/adaptivebox/global/RandomGenerator.java
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+/**
+ * Description: For generating random numbers.
+ *
+ * Author          Create/Modi     Note
+ * Xiaofeng Xie    Feb 22, 2001
+ *
+ * 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.
+ *
+ * Please acknowledge the author(s) if you use this code in any way.
+ *
+ * @version 1.0
+ * @Since MAOS1.0
+ */
+
+package net.adaptivebox.global;
+
+import java.util.Random;
+import java.security.SecureRandom;
+
+public class RandomGenerator {
+  /**
+   * Pseudo-random number generator instance.
+   */
+  private static Random PRNG = new Random();
+
+  /**
+   * Switch between weaker, but faster pseudo-random number generator and
+   * stronger, but slower.
+   *
+   * @param stronger activation of secure pseudo random generator flag
+   */
+  public static void useStrongerGenerator(boolean stronger) {
+    if(stronger == true) {
+      PRNG = new SecureRandom();
+    } else {
+      PRNG = new Random();
+    }
+  }
+
+  /**
+   * This function returns a random integer number between the lowLimit and
+   * upLimit.
+   *
+   * @param lowLimit lower limits upLimit The upper limits (between which the
+   *                 random number is to be generated)
+   * @return int return value Example: for find [0,1,2]
+   */
+  public static int intRangeRandom(int lowLimit, int upLimit) {
+    int num = lowLimit + PRNG.nextInt(upLimit - lowLimit + 1);
+    return num;
+  }
+
+  /**
+   * This function returns a random float number between the lowLimit and upLimit.
+   *
+   * @param lowLimit lower limits upLimit The upper limits (between which the
+   *                 random number is to be generated)
+   * @return double return value
+   */
+  public static double doubleRangeRandom(double lowLimit, double upLimit) {
+    double num = lowLimit + PRNG.nextDouble() * (upLimit - lowLimit);
+    return num;
+  }
+
+  /**
+   * This function returns a random float number between the zero (inclusive) and one (exclusive).
+   *
+   * @return double value in the range [0, 1)
+   */
+  public static double doubleZeroOneRandom() {
+    return PRNG.nextDouble();
+  }
+
+  public static int[] randomSelection(int maxNum, int times) {
+    if (maxNum < 0) {
+      maxNum = 0;
+    }
+
+    if (times < 0) {
+      times = 0;
+    }
+
+    int[] all = new int[maxNum];
+    for (int i = 0; i < all.length; i++) {
+      all[i] = i;
+    }
+
+    /* https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle */
+    int[] indices = new int[Math.min(maxNum, times)];
+    for (int i = 0, j, value; i < indices.length; i++) {
+      j = intRangeRandom(i, all.length - 1);
+
+      value = all[j];
+      all[j] = all[i];
+      indices[i] = all[i] = value;
+    }
+
+    return indices;
+  }
+}