std::beta, std::betaf, std::betal

  1. Computes the beta function of x and y.

# Declarations

double beta( double x, double y );
float betaf( float x, float y );
long double betal( long double x, long double y );

Promoted beta( Arithmetic x, Arithmetic y );

# Parameters

# Notes

Implementations that do not support TR 29124 but support TR 19768, provide this function in the header tr1/cmath and namespace std::tr1.

An implementation of this function is also available in boost.math.

beta(x, y) equals beta(y, x).

# Example

#define __STDCPP_WANT_MATH_SPEC_FUNCS__ 1
#include <cmath>
#include <iomanip>
#include <iostream>
#include <string>
 
double binom(int n, int k)
{
    return 1 / ((n + 1) * std::beta(n - k + 1, k + 1));
}
 
int main()
{
    std::cout << "Pascal's triangle:\n";
    for (int n = 1; n < 10; ++n)
    {
        std::cout << std::string(20 - n * 2, ' ');
        for (int k = 1; k < n; ++k)
            std::cout << std::setw(3) << binom(n, k) << ' ';
        std::cout << '\n';
    }
}

# See also