Automatic Differentiation
 
Loading...
Searching...
No Matches
inv_sqrt.hpp
Go to the documentation of this file.
1#ifndef STAN_MATH_PRIM_FUN_INV_SQRT_HPP
2#define STAN_MATH_PRIM_FUN_INV_SQRT_HPP
3
10#include <cmath>
11
12namespace stan {
13namespace math {
14
15template <typename T, require_stan_scalar_t<T>* = nullptr>
16inline auto inv_sqrt(T x) {
17 using std::sqrt;
18 return inv(sqrt(x));
19}
28 template <typename T>
29 static inline auto fun(const T& x) {
30 return inv_sqrt(x);
31 }
32};
33
42template <typename Container,
47 Container>* = nullptr>
48inline auto inv_sqrt(const Container& x) {
50}
51
60template <typename Container, require_not_var_matrix_t<Container>* = nullptr,
61 require_container_st<std::is_arithmetic, Container>* = nullptr>
62inline auto inv_sqrt(const Container& x) {
63// Eigen 3.4.0 has precision issues on ARM64 with vectorised rsqrt
64// Resolved in current master branch, below can be removed on next release
65#ifdef __aarch64__
67#else
69 x, [](const auto& v) { return v.array().rsqrt(); });
70#endif
71}
72
73} // namespace math
74} // namespace stan
75
76#endif
require_not_t< container_type_check_base< is_container, scalar_type_t, TypeCheck, Check... > > require_not_container_st
Require type does not satisfy is_container.
require_all_not_t< is_nonscalar_prim_or_rev_kernel_expression< std::decay_t< Types > >... > require_all_not_nonscalar_prim_or_rev_kernel_expression_t
Require none of the types satisfy is_nonscalar_prim_or_rev_kernel_expression.
rsqrt_< as_operation_cl_t< T > > rsqrt(T &&a)
require_not_t< is_stan_scalar< std::decay_t< T > > > require_not_stan_scalar_t
Require type does not satisfy is_stan_scalar.
require_not_t< is_var_matrix< std::decay_t< T > > > require_not_var_matrix_t
Require type does not satisfy is_var_matrix.
fvar< T > sqrt(const fvar< T > &x)
Definition sqrt.hpp:17
fvar< T > inv_sqrt(const fvar< T > &x)
Definition inv_sqrt.hpp:12
fvar< T > inv(const fvar< T > &x)
Definition inv.hpp:12
The lgamma implementation in stan-math is based on either the reentrant safe lgamma_r implementation ...
Base template class for vectorization of unary scalar functions defined by a template class F to a sc...
static auto fun(const T &x)
Definition inv_sqrt.hpp:29
Structure to wrap 1 / sqrt(x) so that it can be vectorized.
Definition inv_sqrt.hpp:27