std::student_t_distribution

template <class RealType = double> class student_t_distribution;

Student T-Distribution

Random number distribution that produces floating-point values according to a Student T-distribution, which is described by the following probability density function:

This distribution produces random numbers as the result of normalizing the values of a relatively small sample (n+1 values) of independent normally-distributed values. As the sample size increases, the distribution approaches a standard normal distribution.

The distribution parameter, n, is set on construction.

To produce a random value following this distribution, call its member function operator().

Template parameters

RealType: A floating-point type. Aliased as member type result_type.
By default, this is double.

Member types

The following aliases are member types of normal_distribution:

member type	definition	notes
`result_type`	The first template parameter (`RealType`)	The type of the numbers generated (defaults to `double`)
`param_type`	not specified	The type returned by member param.

Member functions

(constructor): Construct Student T-distribution (public member function)

operator(): Generate random number (public member function)

reset: Reset distribution (public member function)

param: Distribution parameters (public member function)

min: Minimum value (public member function)

max: Maximum value (public member function)

Distribution parameters:

student_t_distribution::n: Degrees of freedom (public member function)

Non-member functions

operator<<: Insert into output stream (function template)

operator>>: Extract from input stream (function template)

relational operators: Relational operators (function template)

Example

// student_t_distribution #include <iostream> #include <random> int main() { const int nrolls=10000; // number of experiments const int nstars=100; // maximum number of stars to distribute // intervals definitions: const int nintervals=12; const double first=-3.0; const double span=0.5; std::default_random_engine generator; std::student_t_distribution<double> distribution(10.0); int p[nintervals]={}; for (int i=0; i<nrolls; ++i) { double number = distribution(generator); if ((number>=first)&&(number<first+nintervals*span)) ++p[int((number-first)/span)]; } std::cout << "fisher_f_distribution (10.0):" << std::endl; std::cout << std::fixed; std::cout.precision(1); for (int i=0; i<nintervals; ++i) { std::cout.width(4); std::cout << (first+i*span) << ".."; std::cout.width(4); std::cout << (first+(i+1)*span) << ": "; std::cout << std::string(p[i]*nstars/nrolls,'*') << std::endl; } return 0; }

Possible output:

 student_t_distribution (10.0): -3.0..-2.5: -2.5..-2.0: ** -2.0..-1.5: **** -1.5..-1.0: ********* -1.0..-0.5: *************** -0.5.. 0.0: ******************** 0.0.. 0.5: ********************* 0.5.. 1.0: *************** 1.0.. 1.5: ********* 1.5.. 2.0: **** 2.0.. 2.5: ** 2.5.. 3.0: *

distributions

generators

other

member functions

non-member functions