E.V.E  0.1-beta

◆ zeta

eve::zeta = {}
inlineconstexpr

Callable object computing the the Riemann \(\zeta\) function: \(\displaystyle \zeta(s)=\sum_{n=0}^\infty \frac1{n^s}\).

Required header: #include <eve/function/zeta.hpp>

Members Functions

Member Effect
operator() the zeta operation
operator[] Construct a conditional version of current function object

auto operator()( floating_real_value auto s) const noexcept;
Definition: value.hpp:103

Parameters

x: floating_value.

Return value

Returns elementwise \(\displaystyle \zeta(s)=\sum_{n=0}^\infty \frac1{n^s}\)

For negative entries the computation is made using the reflection formula.

The result type is of the same type as the parameter.


auto operator[]( conditional_expression auto cond ) const noexcept;

Higher-order function generating a masked version of eve::zeta

Parameters

cond : conditional expression

Return value

A Callable object so that the expression zeta[cond](x, ...) is equivalent to if_else(cond,zeta(x, ...),x)


Supported decorators

no decorators are supported

Example

See it live on Compiler Explorer

#include <eve/function/zeta.hpp>
#include <eve/wide.hpp>
#include <eve/constant/eps.hpp>
#include <eve/constant/inf.hpp>
#include <eve/constant/minf.hpp>
#include <eve/constant/nan.hpp>
#include <iostream>
int main()
{
wide_ft pf = {0.0f, -1.0f, 1.0f, -1.5f, 1.5f, -2.0f, 2.0f, -12.0f};
std::cout << "---- simd" << '\n'
<< "<- pf = " << pf << '\n'
<< "-> zeta(pf) = " << eve::zeta(pf) << '\n';
float xf = 2.0f;
std::cout << "---- scalar" << '\n'
<< "<- xf = " << xf << '\n'
<< "-> zeta(xf) = " << eve::zeta(xf) << '\n';
return 0;
}
constexpr pedantic_type const pedantic
Higher-order Callable Object imbuing more standard semantic onto other Callable Objects.
Definition: pedantic.hpp:56
constexpr callable_zeta_ zeta
Callable object computing the the Riemann function: .
Definition: zeta.hpp:76
Wrapper for SIMD registers.
Definition: wide.hpp:65