Howard Hinnant 551d8e4ddb [rand.dist.samp.discrete]
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@104103 91177308-0d34-0410-b5e6-96231b3b80d8
2010-05-19 01:53:57 +00:00

61 lines
1.5 KiB
C++

//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// <random>
// template<class IntType = int>
// class discrete_distribution
// template<class UnaryOperation>
// discrete_distribution(size_t nw, double xmin, double xmax,
// UnaryOperation fw);
#include <random>
#include <cassert>
double fw(double x)
{
return x+1;
}
int main()
{
{
typedef std::discrete_distribution<> D;
D d(0, 0, 1, fw);
std::vector<double> p = d.probabilities();
assert(p.size() == 1);
assert(p[0] == 1);
}
{
typedef std::discrete_distribution<> D;
D d(1, 0, 1, fw);
std::vector<double> p = d.probabilities();
assert(p.size() == 1);
assert(p[0] == 1);
}
{
typedef std::discrete_distribution<> D;
D d(2, 0.5, 1.5, fw);
std::vector<double> p = d.probabilities();
assert(p.size() == 2);
assert(p[0] == .4375);
assert(p[1] == .5625);
}
{
typedef std::discrete_distribution<> D;
D d(4, 0, 2, fw);
std::vector<double> p = d.probabilities();
assert(p.size() == 4);
assert(p[0] == .15625);
assert(p[1] == .21875);
assert(p[2] == .28125);
}
}