double sph_neumann ( unsigned n, double x );
/* floating-point-type */ sph_neumann( unsigned n,
/* floating-point-type */ x );
float sph_neumannf( unsigned n, float x );
(2) (since C++17)long double sph_neumannl( unsigned n, long double x );
(3) (since C++17)template< class Integer >
double sph_neumann ( unsigned n, Integer x );
Computes the
spherical Bessel function of the second kind, also known as the spherical Neumann function, of
nand
x.
The library provides overloads ofstd::sph_neumann
for all cv-unqualified floating-point types as the type of the parameter x.(since C++23)
A) Additional overloads are provided for all integer types, which are treated as double.
[edit] Parameters n - the order of the function x - the argument of the function [edit] Return valueIf no errors occur, returns the value of the spherical Bessel function of the second kind (spherical Neumann function) of n and x, that is nn(x) = (Ï/2x)1/2
Nn+1/2(x) where Nn(x) is std::cyl_neumann(n, x) and xâ¥0.
Errors may be reported as specified in math_errhandling
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 argument num of integer type, std::sph_neumann(int_num, num) has the same effect as std::sph_neumann(int_num, static_cast<double>(num)).
[edit] Example#include <cmath> #include <iostream> int main() { // spot check for n == 1 double x = 1.2345; std::cout << "n_1(" << x << ") = " << std::sph_neumann(1, x) << '\n'; // exact solution for n_1 std::cout << "-cos(x)/x² - sin(x)/x = " << -std::cos(x) / (x * x) - std::sin(x) / x << '\n'; }
Output:
n_1(1.2345) = -0.981201 -cos(x)/x² - sin(x)/x = -0.981201[edit] See also [edit] External links
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4