std::ellint_3, std::ellint_3f, std::ellint_3l

Header: <cmath>

1-3) Computes the incomplete elliptic integral of the third kind of k, nu, and phi.The library provides overloads of std::ellint_3 for all cv-unqualified floating-point types as the type of the parameters k, nu and phi.(since C++23)

# Declarations

float ellint_3 ( float k, float nu, float phi );
double ellint_3 ( double k, double nu, double phi );
long double ellint_3 ( long double k, long double nu, long double phi );

(since C++17) (until C++23)

/* floating-point-type */ ellint_3( /* floating-point-type */ k,
/* floating-point-type */ nu,
/* floating-point-type */ phi );

(since C++23)

float ellint_3f( float k, float nu, float phi );

(since C++17)

long double ellint_3l( long double k, long double nu, long double phi );

(since C++17)

Additional overloads
template< class Arithmetic1, class Arithmetic2, class Arithmetic3 >
/* common-floating-point-type */
ellint_3( Arithmetic1 k, Arithmetic2 nu, Arithmetic3 phi );

(since C++17)

# Parameters

# Notes

Implementations that do not support C++17, but support ISO 29124:2010, provide this function if STDCPP_MATH_SPEC_FUNCS is defined by the implementation to a value at least 201003L and if the user defines STDCPP_WANT_MATH_SPEC_FUNCS before including any standard library headers.

Implementations that do not support ISO 29124:2010 but support TR 19768:2007 (TR1), provide this function in the header tr1/cmath and namespace std::tr1.

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

The additional overloads are not required to be provided exactly as (A). They only need to be sufficient to ensure that for their first argument num1, second argument num2 and third argument num3:

If num1, num2 and num3 have arithmetic types, then std::ellint_3(num1, num2, num3) has the same effect as std::ellint_3(static_cast</* common-floating-point-type />(num1),static_cast</ common-floating-point-type />(num2),static_cast</ common-floating-point-type />(num3)), where / common-floating-point-type */ is the floating-point type with the greatest floating-point conversion rank and greatest floating-point conversion subrank among the types of num1, num2 and num3, arguments of integer type are considered to have the same floating-point conversion rank as double.

If no such floating-point type with the greatest rank and subrank exists, then overload resolution does not result in a usable candidate from the overloads provided.

# Example

#include <cmath>
#include <iostream>
#include <numbers>
 
int main()
{
    const double hpi = std::numbers::pi / 2;
 
    std::cout << "Π(0,0,π/2) = " << std::ellint_3(0, 0, hpi) << '\n'
              << "π/2 = " << hpi << '\n';
}

# See also