diff options
-rw-r--r-- | Eigen/src/Core/MathFunctions.h | 12 | ||||
-rw-r--r-- | test/rand.cpp | 43 |
2 files changed, 42 insertions, 13 deletions
diff --git a/Eigen/src/Core/MathFunctions.h b/Eigen/src/Core/MathFunctions.h index 9934e5601..ac7ef6d23 100644 --- a/Eigen/src/Core/MathFunctions.h +++ b/Eigen/src/Core/MathFunctions.h @@ -615,16 +615,18 @@ struct random_default_impl<Scalar, false, true> typedef typename conditional<NumTraits<Scalar>::IsSigned,std::ptrdiff_t,std::size_t>::type ScalarX; if(y<x) return x; + // the following difference might overflow on a 32 bits system, + // but since y>=x the result converted to an unsigned long is still correct. 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); - + std::size_t divisor = 1; + std::size_t multiplier = 1; + if(range<RAND_MAX) divisor = (std::size_t(RAND_MAX)+1)/(range+1); + else multiplier = 1 + range/(std::size_t(RAND_MAX)+1); do { - offset = ( (std::size_t(std::rand()) * multiplier) / divisor ); + offset = (std::size_t(std::rand()) * multiplier) / divisor; } while (offset > range); - return Scalar(ScalarX(x) + offset); } diff --git a/test/rand.cpp b/test/rand.cpp index eeec34191..51cf01773 100644 --- a/test/rand.cpp +++ b/test/rand.cpp @@ -9,6 +9,8 @@ #include "main.h" +typedef long long int64; + template<typename Scalar> Scalar check_in_range(Scalar x, Scalar y) { Scalar r = internal::random<Scalar>(x,y); @@ -35,31 +37,49 @@ template<typename Scalar> void check_all_in_range(Scalar x, Scalar y) VERIFY( (mask>0).all() ); } +template<typename Scalar> void check_histogram(Scalar x, Scalar y, int bins) +{ + Array<int,1,Dynamic> hist(bins); + hist.fill(0); + int f = 100000; + int n = bins*f; + int64 range = int64(y)-int64(x); + int divisor = int((range+1)/bins); + assert(((range+1)%bins)==0); + for(int k=0; k<n; ++k) + { + Scalar r = check_in_range(x,y); + hist( int((int64(r)-int64(x))/divisor) )++; + } + VERIFY( (((hist.cast<double>()/double(f))-1.0).abs()<0.02).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++) { + + for(int i = 0; i < g_repeat*10000; 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<int>(-RAND_MAX+10,RAND_MAX-10)); 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)); @@ -67,25 +87,32 @@ void test_rand() 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)); + + CALL_SUBTEST(check_histogram<int>(-5,5,11)); + int bins = 100; + CALL_SUBTEST(check_histogram<int>(-3333,-3333+bins*(3333/bins)-1,bins)); + bins = 1000; + CALL_SUBTEST(check_histogram<int>(-RAND_MAX+10,-RAND_MAX+10+bins*(RAND_MAX/bins)-1,bins)); + CALL_SUBTEST(check_histogram<int>(-RAND_MAX+10,-int64(RAND_MAX)+10+bins*(2*int64(RAND_MAX)/bins)-1,bins)); } |