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bug #1275: Copied improved random<> implementation from devel-branch (originally introduced in f329d0908af35fd17bdc4dfeb87046dcaa6e6937

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This commit is contained in:
Christoph Hertzberg 2016-08-15 15:04:53 +02:00
parent c40006d0b9
commit ab2a3e3c1c
3 changed files with 106 additions and 3 deletions
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17
Eigen/src/Core/MathFunctions.h
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@ -507,11 +507,22 @@ struct floor_log2<n, lower, upper, floor_log2_bogus>
template<typename Scalar>
struct random_default_impl<Scalar, false, true>
{
typedef typename NumTraits<Scalar>::NonInteger NonInteger;
static inline Scalar run(const Scalar& x, const Scalar& y)
{
return x + Scalar((NonInteger(y)-x+1) * std::rand() / (RAND_MAX + NonInteger(1)));
typedef typename conditional<NumTraits<Scalar>::IsSigned,std::ptrdiff_t,std::size_t>::type ScalarX;
if(y<x)
return x;
std::size_t range = ScalarX(y)-ScalarX(x);
std::size_t offset = 0;
// rejection sampling
std::size_t divisor = (range+RAND_MAX-1)/(range+1);
std::size_t multiplier = (range+RAND_MAX-1)/std::size_t(RAND_MAX);
do {
offset = ( (std::size_t(std::rand()) * multiplier) / divisor );
} while (offset > range);
return Scalar(ScalarX(x) + offset);
}
static inline Scalar run()

1
test/CMakeLists.txt
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@ -125,6 +125,7 @@ endif(TEST_LIB)
set_property(GLOBAL PROPERTY EIGEN_CURRENT_SUBPROJECT "Official")
add_custom_target(BuildOfficial)
ei_add_test(rand)
ei_add_test(meta)
ei_add_test(sizeof)
ei_add_test(dynalloc)

91
test/rand.cpp Normal file
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@ -0,0 +1,91 @@
// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2015 Gael Guennebaud <gael.guennebaud@inria.fr>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
#include "main.h"
template<typename Scalar> Scalar check_in_range(Scalar x, Scalar y)
{
Scalar r = internal::random<Scalar>(x,y);
VERIFY(r>=x);
if(y>=x)
{
VERIFY(r<=y);
}
return r;
}
template<typename Scalar> void check_all_in_range(Scalar x, Scalar y)
{
Array<int,1,Dynamic> mask(y-x+1);
mask.fill(0);
long n = (y-x+1)*32;
for(long k=0; k<n; ++k)
{
mask( check_in_range(x,y)-x )++;
}
for(DenseIndex i=0; i<mask.size(); ++i)
if(mask(i)==0)
std::cout << "WARNING: value " << x+i << " not reached." << std::endl;
VERIFY( (mask>0).all() );
}
void test_rand()
{
long long_ref = NumTraits<long>::highest()/10;
signed char char_offset = (std::min)(g_repeat,64);
signed char short_offset = (std::min)(g_repeat,16000);
for(int i = 0; i < g_repeat*10; i++) {
CALL_SUBTEST(check_in_range<float>(10,11));
CALL_SUBTEST(check_in_range<float>(1.24234523,1.24234523));
CALL_SUBTEST(check_in_range<float>(-1,1));
CALL_SUBTEST(check_in_range<float>(-1432.2352,-1432.2352));
CALL_SUBTEST(check_in_range<double>(10,11));
CALL_SUBTEST(check_in_range<double>(1.24234523,1.24234523));
CALL_SUBTEST(check_in_range<double>(-1,1));
CALL_SUBTEST(check_in_range<double>(-1432.2352,-1432.2352));
CALL_SUBTEST(check_in_range<int>(0,-1));
CALL_SUBTEST(check_in_range<short>(0,-1));
CALL_SUBTEST(check_in_range<long>(0,-1));
CALL_SUBTEST(check_in_range<int>(-673456,673456));
CALL_SUBTEST(check_in_range<short>(-24345,24345));
CALL_SUBTEST(check_in_range<long>(-long_ref,long_ref));
}
CALL_SUBTEST(check_all_in_range<signed char>(11,11));
CALL_SUBTEST(check_all_in_range<signed char>(11,11+char_offset));
CALL_SUBTEST(check_all_in_range<signed char>(-5,5));
CALL_SUBTEST(check_all_in_range<signed char>(-11-char_offset,-11));
CALL_SUBTEST(check_all_in_range<signed char>(-126,-126+char_offset));
CALL_SUBTEST(check_all_in_range<signed char>(126-char_offset,126));
CALL_SUBTEST(check_all_in_range<signed char>(-126,126));
CALL_SUBTEST(check_all_in_range<short>(11,11));
CALL_SUBTEST(check_all_in_range<short>(11,11+short_offset));
CALL_SUBTEST(check_all_in_range<short>(-5,5));
CALL_SUBTEST(check_all_in_range<short>(-11-short_offset,-11));
CALL_SUBTEST(check_all_in_range<short>(-24345,-24345+short_offset));
CALL_SUBTEST(check_all_in_range<short>(24345,24345+short_offset));
CALL_SUBTEST(check_all_in_range<int>(11,11));
CALL_SUBTEST(check_all_in_range<int>(11,11+g_repeat));
CALL_SUBTEST(check_all_in_range<int>(-5,5));
CALL_SUBTEST(check_all_in_range<int>(-11-g_repeat,-11));
CALL_SUBTEST(check_all_in_range<int>(-673456,-673456+g_repeat));
CALL_SUBTEST(check_all_in_range<int>(673456,673456+g_repeat));
CALL_SUBTEST(check_all_in_range<long>(11,11));
CALL_SUBTEST(check_all_in_range<long>(11,11+g_repeat));
CALL_SUBTEST(check_all_in_range<long>(-5,5));
CALL_SUBTEST(check_all_in_range<long>(-11-g_repeat,-11));
CALL_SUBTEST(check_all_in_range<long>(-long_ref,-long_ref+g_repeat));
CALL_SUBTEST(check_all_in_range<long>( long_ref, long_ref+g_repeat));
}