Page Menu
Home
c4science
Search
Configure Global Search
Log In
Files
F86108019
BetaDistribution.hpp
No One
Temporary
Actions
Download File
Edit File
Delete File
View Transforms
Subscribe
Mute Notifications
Award Token
Subscribers
None
File Metadata
Details
File Info
Storage
Attached
Created
Fri, Oct 4, 08:03
Size
3 KB
Mime Type
text/x-c++
Expires
Sun, Oct 6, 08:03 (2 d)
Engine
blob
Format
Raw Data
Handle
21350904
Attached To
R8820 scATAC-seq
BetaDistribution.hpp
View Options
#include <iostream>
#include <sstream>
#include <string>
#include <random>
template <typename RealType = double>
/*!
* \brief The beta_distribution class implements
* a beta distribution to sample from.
* The code has been taken
* from https://gist.github.com/sftrabbit/5068941
*/
class beta_distribution
{
public:
typedef RealType result_type;
class param_type
{
public:
typedef beta_distribution distribution_type;
explicit param_type(RealType a = 2.0, RealType b = 2.0)
: a_param(a), b_param(b) { }
RealType a() const { return a_param; }
RealType b() const { return b_param; }
bool operator==(const param_type& other) const
{
return (a_param == other.a_param &&
b_param == other.b_param);
}
bool operator!=(const param_type& other) const
{
return !(*this == other);
}
private:
RealType a_param, b_param;
};
explicit beta_distribution(RealType a = 2.0, RealType b = 2.0)
: a_gamma(a), b_gamma(b) { }
explicit beta_distribution(const param_type& param)
: a_gamma(param.a()), b_gamma(param.b()) { }
void reset() { }
param_type param() const
{
return param_type(a(), b());
}
void param(const param_type& param)
{
a_gamma = gamma_dist_type(param.a());
b_gamma = gamma_dist_type(param.b());
}
template <typename URNG>
result_type operator()(URNG& engine)
{
return generate(engine, a_gamma, b_gamma);
}
template <typename URNG>
result_type operator()(URNG& engine, const param_type& param)
{
gamma_dist_type a_param_gamma(param.a()),
b_param_gamma(param.b());
return generate(engine, a_param_gamma, b_param_gamma);
}
result_type min() const { return 0.0; }
result_type max() const { return 1.0; }
result_type a() const { return a_gamma.alpha(); }
result_type b() const { return b_gamma.alpha(); }
bool operator==(const beta_distribution<result_type>& other) const
{
return (param() == other.param() &&
a_gamma == other.a_gamma &&
b_gamma == other.b_gamma);
}
bool operator!=(const beta_distribution<result_type>& other) const
{
return !(*this == other);
}
private:
typedef std::gamma_distribution<result_type> gamma_dist_type;
gamma_dist_type a_gamma, b_gamma;
template <typename URNG>
result_type generate(URNG& engine,
gamma_dist_type& x_gamma,
gamma_dist_type& y_gamma)
{
result_type x = x_gamma(engine);
return x / (x + y_gamma(engine));
}
} ;
template <typename CharT, typename RealType>
std::basic_ostream<CharT>& operator<<(std::basic_ostream<CharT>& os,
const beta_distribution<RealType>& beta)
{
os << "~Beta(" << beta.a() << "," << beta.b() << ")";
return os;
}
template <typename CharT, typename RealType>
std::basic_istream<CharT>& operator>>(std::basic_istream<CharT>& is,
beta_distribution<RealType>& beta)
{
std::string str;
RealType a, b;
if (std::getline(is, str, '(') && str == "~Beta" &&
is >> a && is.get() == ',' && is >> b && is.get() == ')') {
beta = beta_distribution<RealType>(a, b);
} else {
is.setstate(std::ios::failbit);
}
return is;
}
Event Timeline
Log In to Comment