src/xbt/random_test.cpp

   1 /* Copyright (c) 2019-2021. The SimGrid Team. All rights reserved.               */
   2
   3 /* This program is free software; you can redistribute it and/or modify it
   4  * under the terms of the license (GNU LGPL) which comes with this package. */
   5
   6 #include "src/include/catch.hpp"
   7 #include "xbt/log.h"
   8 #include "xbt/random.hpp"
   9 #include <random>
  10 #include <cmath>
  11
  12 #define EpsilonApprox(a) Catch::Matchers::WithinAbs((a), 100 * std::numeric_limits<double>::epsilon())
  13
  14 TEST_CASE("xbt::random: Random Number Generation")
  15 {
  16   SECTION("Using XBT_RNG_xbt")
  17   {
  18     simgrid::xbt::random::set_implem_xbt();
  19     simgrid::xbt::random::set_mersenne_seed(12345);
  20     REQUIRE_THAT(simgrid::xbt::random::exponential(25), EpsilonApprox(0.00291934351538427348));
  21     REQUIRE(simgrid::xbt::random::uniform_int(1, 6) == 4);
  22     REQUIRE_THAT(simgrid::xbt::random::uniform_real(0, 1), EpsilonApprox(0.31637556043369124970));
  23     REQUIRE_THAT(simgrid::xbt::random::normal(0, 2), EpsilonApprox(1.62746784745133976635));
  24   }
  25
  26   SECTION("Using XBT_RNG_std")
  27   {
  28     std::mt19937 gen;
  29     gen.seed(12345);
  30
  31     simgrid::xbt::random::set_implem_std();
  32     simgrid::xbt::random::set_mersenne_seed(12345);
  33
  34     std::exponential_distribution<> distA(25);
  35     std::uniform_int_distribution<> distB(1, 6);
  36     std::uniform_real_distribution<> distC(0, 1);
  37     std::normal_distribution<> distD(0, 2);
  38
  39     REQUIRE_THAT(simgrid::xbt::random::exponential(25), EpsilonApprox(distA(gen)));
  40     REQUIRE(simgrid::xbt::random::uniform_int(1, 6) == distB(gen));
  41     REQUIRE_THAT(simgrid::xbt::random::uniform_real(0, 1), EpsilonApprox(distC(gen)));
  42     REQUIRE_THAT(simgrid::xbt::random::normal(0, 2), EpsilonApprox(distD(gen)));
  43   }
  44
  45   SECTION("XBT_RNG_std write to a file")
  46   {
  47     simgrid::xbt::random::set_implem_std();
  48     simgrid::xbt::random::set_mersenne_seed(12345);
  49
  50     simgrid::xbt::random::exponential(25);
  51     bool writtenA = simgrid::xbt::random::write_mersenne_state("rdm_state_tmp.txt");
  52     double resB = simgrid::xbt::random::uniform_real(10, 20);
  53     double resC = simgrid::xbt::random::normal(0, 2);
  54     bool writtenB = simgrid::xbt::random::read_mersenne_state("rdm_state_tmp.txt");
  55     REQUIRE(writtenA);
  56     REQUIRE(writtenB);
  57     REQUIRE_THAT(simgrid::xbt::random::uniform_real(10, 20), EpsilonApprox(resB));
  58     REQUIRE_THAT(simgrid::xbt::random::normal(0, 2), EpsilonApprox(resC));
  59     if (writtenB) {
  60       std::remove("rdm_state_tmp.txt");
  61     }
  62   }
  63 }