Diff: random.cpp

Revision:

0:b47c2a7920c2

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/random.cpp	Fri Mar 16 16:34:18 2018 +0000
@@ -0,0 +1,353 @@
+///\file
+
+/******************************************************************************
+The MIT License(MIT)
+
+Embedded Template Library.
+https://github.com/ETLCPP/etl
+http://www.etlcpp.com
+
+Copyright(c) 2017 jwellbelove
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files(the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions :
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+******************************************************************************/
+
+#include "platform.h"
+#include "random.h"
+
+namespace etl
+{
+  //***************************************************************************
+  // XOR Shift
+  //***************************************************************************
+
+  //***************************************************************************
+  /// Default constructor.
+  /// Attempts to come up with a unique non-zero seed.
+  //***************************************************************************
+  random_xorshift::random_xorshift()
+  {
+    // An attempt to come up with a unique non-zero seed,
+    // based on the address of the instance.
+    uintptr_t n    = reinterpret_cast<uintptr_t>(this);
+    uint32_t  seed = static_cast<uint32_t>(n);
+    initialise(seed);
+  }
+
+  //***************************************************************************
+  /// Constructor with seed value.
+  ///\param seed The new seed value.
+  //***************************************************************************
+  random_xorshift::random_xorshift(uint32_t seed)
+  {
+    initialise(seed);
+  }
+
+  //***************************************************************************
+  /// Initialises the sequence with a new seed value.
+  ///\param seed The new seed value.
+  //***************************************************************************
+  void random_xorshift::initialise(uint32_t seed)
+  {
+    // Add the first four primes to ensure that the seed isn't zero.
+    state[0] = seed + 3;
+    state[1] = seed + 5;
+    state[2] = seed + 7;
+    state[3] = seed + 11;
+  }
+
+  //***************************************************************************
+  /// Get the next random_xorshift number.
+  //***************************************************************************
+  uint32_t random_xorshift::operator()()
+  {
+    uint32_t n = state[3];
+    n ^= n << 11;
+    n ^= n >> 8;
+    state[3] = state[2];
+    state[2] = state[1];
+    state[1] = state[0];
+    n ^= state[0];
+    n ^= state[0] >> 19;
+    state[0] = n;
+
+    return n;
+  }
+
+  //***************************************************************************
+  /// Get the next random_xorshift number in a specified inclusive range.
+  //***************************************************************************
+  uint32_t random_xorshift::range(uint32_t low, uint32_t high)
+  {
+    uint32_t r = high - low + 1;
+    uint32_t n = operator()();
+    n %= r;
+    n += low;
+
+    return n;
+  }
+
+  //***************************************************************************
+  // Linear Congruential Generator
+  //***************************************************************************
+
+  //***************************************************************************
+  /// Default constructor.
+  /// Attempts to come up with a unique non-zero seed.
+  //***************************************************************************
+  random_lcg::random_lcg()
+  {
+    // An attempt to come up with a unique non-zero seed,
+    // based on the address of the instance.
+    uintptr_t n    = reinterpret_cast<uintptr_t>(this);
+    uint32_t  seed = static_cast<uint32_t>(n);
+    initialise(seed);
+  }
+
+  //***************************************************************************
+  /// Constructor with seed value.
+  ///\param seed The new seed value.
+  //***************************************************************************
+  random_lcg::random_lcg(uint32_t seed)
+  {
+    initialise(seed);
+  }
+
+  //***************************************************************************
+  /// Initialises the sequence with a new seed value.
+  ///\param seed The new seed value.
+  //***************************************************************************
+  void random_lcg::initialise(uint32_t seed)
+  {
+    seed = (seed == 0) ? 1 : seed;
+    value = (seed > m) ? m : seed;
+  }
+
+  //***************************************************************************
+  /// Get the next random_clcg number.
+  //***************************************************************************
+  uint32_t random_lcg::operator()()
+  {
+    value = (a * value) % m;
+
+    return value;
+  }
+
+  //***************************************************************************
+  /// Get the next random_clcg number in a specified inclusive range.
+  //***************************************************************************
+  uint32_t random_lcg::range(uint32_t low, uint32_t high)
+  {
+    uint32_t r = high - low + 1;
+    uint32_t n = operator()();
+    n %= r;
+    n += low;
+
+    return n;
+  }
+
+  //***************************************************************************
+  // Combined Linear Congruential Generator
+  //***************************************************************************
+
+  //***************************************************************************
+  /// Default constructor.
+  /// Attempts to come up with a unique non-zero seed.
+  //***************************************************************************
+  random_clcg::random_clcg()
+  {
+    // An attempt to come up with a unique non-zero seed,
+    // based on the address of the instance.
+    uintptr_t n = reinterpret_cast<uintptr_t>(this);
+    uint32_t  seed = static_cast<uint32_t>(n);
+    initialise(seed);
+  }
+
+  //***************************************************************************
+  /// Constructor with seed value.
+  ///\param seed The new seed value.
+  //***************************************************************************
+  random_clcg::random_clcg(uint32_t seed)
+  {
+    initialise(seed);
+  }
+
+  //***************************************************************************
+  /// Initialises the sequence with a new seed value.
+  ///\param seed The new seed value.
+  //***************************************************************************
+  void random_clcg::initialise(uint32_t seed)
+  {
+    seed = (seed == 0) ? 1 : seed;
+    value1 = (seed > m1) ? m1 : seed;
+    value2 = (seed > m1) ? m1 : seed;
+  }
+
+  //***************************************************************************
+  /// Get the next random_clcg number.
+  //***************************************************************************
+  uint32_t random_clcg::operator()()
+  {
+    static const uint32_t m = ((m1 > m2) ? m1 : m2);
+
+    value1 = (a1 * value1) % m1;
+    value2 = (a2 * value2) % m2;
+
+    return (value1 + value2) % m;
+  }
+
+  //***************************************************************************
+  /// Get the next random_clcg number in a specified inclusive range.
+  //***************************************************************************
+  uint32_t random_clcg::range(uint32_t low, uint32_t high)
+  {
+    uint32_t r = high - low + 1;
+    uint32_t n = operator()();
+    n %= r;
+    n += low;
+
+    return n;
+  }
+
+  //***************************************************************************
+  // Linear Shift Feedback Register
+  //***************************************************************************
+
+  //***************************************************************************
+  /// Default constructor.
+  /// Attempts to come up with a unique non-zero seed.
+  //***************************************************************************
+  random_lsfr::random_lsfr()
+  {
+    // An attempt to come up with a unique non-zero seed,
+    // based on the address of the instance.
+    uintptr_t n    = reinterpret_cast<uintptr_t>(this);
+    uint32_t  seed = static_cast<uint32_t>(n);
+    initialise(seed);
+  }
+
+  //***************************************************************************
+  /// Constructor with seed value.
+  ///\param seed The new seed value.
+  //***************************************************************************
+  random_lsfr::random_lsfr(uint32_t seed)
+  {
+    initialise(seed);
+  }
+
+  //***************************************************************************
+  /// Initialises the sequence with a new seed value.
+  ///\param seed The new seed value.
+  //***************************************************************************
+  void random_lsfr::initialise(uint32_t seed)
+  {
+    value = seed;
+  }
+
+  //***************************************************************************
+  /// Get the next random_lsfr number.
+  //***************************************************************************
+  uint32_t random_lsfr::operator()()
+  {
+    static const uint32_t polynomial = 0x80200003;
+
+    value >>= 1;
+
+    if ((value & 1) == 1)
+    {
+      value ^= polynomial;
+    }
+
+    return value;
+  }
+
+  //***************************************************************************
+  /// Get the next random_lsfr number in a specified inclusive range.
+  //***************************************************************************
+  uint32_t random_lsfr::range(uint32_t low, uint32_t high)
+  {
+    uint32_t r = high - low + 1;
+    uint32_t n = operator()();
+    n %= r;
+    n += low;
+
+    return n;
+  }
+
+  //***************************************************************************
+  // Multiply with carry random number generator.
+  //***************************************************************************
+
+  //***************************************************************************
+  /// Default constructor.
+  /// Attempts to come up with a unique non-zero seed.
+  //***************************************************************************
+  random_mwc::random_mwc()
+  {
+    // An attempt to come up with a unique non-zero seed,
+    // based on the address of the instance.
+    uintptr_t n = reinterpret_cast<uintptr_t>(this);
+    uint32_t  seed = static_cast<uint32_t>(n);
+    initialise(seed);
+  }
+
+  //***************************************************************************
+  /// Constructor with seed value.
+  ///\param seed The new seed value.
+  //***************************************************************************
+  random_mwc::random_mwc(uint32_t seed)
+  {
+    initialise(seed);
+  }
+
+  //***************************************************************************
+  /// Initialises the sequence with a new seed value.
+  ///\param seed The new seed value.
+  //***************************************************************************
+  void random_mwc::initialise(uint32_t seed)
+  {
+    value1 = seed;
+    value2 = seed;
+  }
+
+  //***************************************************************************
+  /// Get the next random_lsfr number.
+  //***************************************************************************
+  uint32_t random_mwc::operator()()
+  {
+    value1 = 36969 * (value1 & 0xFFFF) + (value1 >> 16);
+    value2 = 18000 * (value2 & 0xFFFF) + (value2 >> 16);
+
+    return (value1 << 16) + value2;
+  }
+
+  //***************************************************************************
+  /// Get the next random_lsfr number in a specified inclusive range.
+  //***************************************************************************
+  uint32_t random_mwc::range(uint32_t low, uint32_t high)
+  {
+    uint32_t r = high - low + 1;
+    uint32_t n = operator()();
+    n %= r;
+    n += low;
+
+    return n;
+  }
+}
+