Reputation: 3144
I would like to know if in C++ standard libraries there is any gaussian distribution number generator, or if you have any code snippet to pass.
Thanks in advance.
Upvotes: 8
Views: 14369
Reputation: 158459
The answer to this question changes with C++11 which has the random header which includes std::normal_distribution. Walter Brown's paper N3551, Random Number Generation in C++11 is probably one of the better introductions to this library.
The following code demonstrates how to use this header (see it live):
#include <iostream>
#include <iomanip>
#include <map>
#include <random>
int main()
{
std::random_device rd;
std::mt19937 e2(rd());
std::normal_distribution<> dist(2, 2);
std::map<int, int> hist;
for (int n = 0; n < 10000; ++n) {
++hist[std::floor(dist(e2))];
}
for (auto p : hist) {
std::cout << std::fixed << std::setprecision(1) << std::setw(2)
<< p.first << ' ' << std::string(p.second/200, '*') << '\n';
}
}
I provide a more general set of examples to random number generation in C++11 in my answer to C++ random float number generation with an example in Boost and using rand()
as well.
Upvotes: 4
Reputation:
C++ Technical Report 1 adds support for random number generation. So if you're using a relatively recent compiler (visual c++ 2008 GCC 4.3), chances are that it is available out of the box.
See here for sample usage of std::tr1::normal_distribution
(and many more).
Upvotes: 13
Reputation: 45345
The GNU Scientific Libraries has this feature. GSL - Gaussian Distribution
Upvotes: 6
Reputation: 247909
The standard library does not. Boost.Random does, however. I'd use that if I were you.
Upvotes: 15