std::hermite, std::hermitef, std::hermitel

 

C++

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Symbols index

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Mathematical special functions

assoc_laguerreassoc_laguerrefassoc_laguerrel   assoc_legendreassoc_legendrefassoc_legendrel betabetafbetal comp_ellint_1comp_ellint_1fcomp_ellint_1l comp_ellint_2comp_ellint_2fcomp_ellint_2l comp_ellint_3comp_ellint_3fcomp_ellint_3l cyl_bessel_icyl_bessel_ifcyl_bessel_il

cyl_bessel_jcyl_bessel_jfcyl_bessel_jl   cyl_bessel_kcyl_bessel_kfcyl_bessel_kl cyl_neumanncyl_neumannfcyl_neumannl ellint_1ellint_1fellint_1l ellint_2ellint_2fellint_2l ellint_3ellint_3fellint_3l expintexpintfexpintl

hermitehermitefhermitel laguerrelaguerreflaguerrel legendrelegendreflegendrel riemann_zetariemann_zetafriemann_zetal sph_besselsph_besselfsph_bessell sph_legendresph_legendrefsph_legendrel sph_neumannsph_neumannfsph_neumannl

 

Defined in header <cmath>
double      hermite ( unsigned int n, double x ); float       hermite ( unsigned int n, float x ); long double hermite ( unsigned int n, long double x ); float       hermitef( unsigned int n, float x ); long double hermitel( unsigned int n, long double x );	(1)	(since C++17)
double      hermite ( unsigned int n, IntegralType x );	(2)	(since C++17)

1) Computes the (physicist's) Hermite polynomials of the degree n and argument x.

2) A set of overloads or a function template accepting an argument of any integral type. Equivalent to (1) after casting the argument to double.

Parameters

n	-	the degree of the polynomial
x	-	the argument, a value of a floating-point or integral type

Return value

If no errors occur, value of the order-n Hermite polynomial of x, that is (-1)n
e^x2

dn

dxn

e^-x2
, is returned.

Error handling

Errors may be reported as specified in math_errhandling.

• If the argument is NaN, NaN is returned and domain error is not reported.
• If n is greater or equal than 128, the behavior is implementation-defined.

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 Hermite polynomials are the polynomial solutions of the equation u,,
-2xu,
= -2nu

The first few are:

• hermite(0, x) = 1
• hermite(1, x) = 2x
• hermite(2, x) = 4x2
  -2
• hermite(3, x) = 8x3
  -12x
• hermite(4, x) = 16x4
  -48x2
  +12

Example

Run this code

#include <cmath>
#include <iostream>
 
double H3(double x) { return 8 * std::pow(x, 3) - 12 * x; }
double H4(double x) { return 16 * std::pow(x, 4) - 48 * x * x + 12; }
 
int main()
{
    // spot-checks
    std::cout << std::hermite(3, 10) << '=' << H3(10) << '\n'
              << std::hermite(4, 10) << '=' << H4(10) << '\n';
}

Output:

7880=7880
155212=155212

See also

laguerrelaguerreflaguerrel (C++17)(C++17)(C++17)	Laguerre polynomials (function)
legendrelegendreflegendrel (C++17)(C++17)(C++17)	Legendre polynomials (function)

External links

Weisstein, Eric W. "Hermite Polynomial." From MathWorld — A Wolfram Web Resource.