mirror of
https://github.com/bolero-MURAKAMI/Sprout.git
synced 2024-12-25 21:35:41 +00:00
103 lines
4.2 KiB
C++
103 lines
4.2 KiB
C++
#ifndef SPROUT_NUMERIC_DFT_DETAIL_DFT_ELEMENT_GEN_HPP
|
|
#define SPROUT_NUMERIC_DFT_DETAIL_DFT_ELEMENT_GEN_HPP
|
|
|
|
#include <iterator>
|
|
#include <type_traits>
|
|
#include <sprout/config.hpp>
|
|
#include <sprout/iterator/operation.hpp>
|
|
#include <sprout/math/sin.hpp>
|
|
#include <sprout/math/cos.hpp>
|
|
#include HDR_ITERATOR_SSCRISK_CEL_OR_SPROUT
|
|
|
|
namespace sprout {
|
|
namespace detail {
|
|
template<typename RandomAccessIterator>
|
|
inline SPROUT_CONSTEXPR typename std::iterator_traits<RandomAccessIterator>::value_type
|
|
dft_element_gen_impl_ra(
|
|
RandomAccessIterator first, RandomAccessIterator last,
|
|
typename std::iterator_traits<RandomAccessIterator>::value_type::value_type arg,
|
|
typename std::iterator_traits<RandomAccessIterator>::difference_type pivot,
|
|
typename std::iterator_traits<RandomAccessIterator>::difference_type k = 0
|
|
)
|
|
{
|
|
typedef typename std::iterator_traits<RandomAccessIterator>::value_type value_type;
|
|
using sprout::cos;
|
|
using sprout::sin;
|
|
return pivot == 0 ? *first * value_type(cos(arg * k), sin(arg * k))
|
|
: sprout::detail::dft_element_gen_impl_ra(
|
|
first, sprout::next(first, pivot), arg, pivot / 2, k
|
|
)
|
|
+ sprout::detail::dft_element_gen_impl_ra(
|
|
sprout::next(first, pivot), last, arg, (NS_SSCRISK_CEL_OR_SPROUT::distance(first, last) - pivot) / 2, k + pivot
|
|
)
|
|
;
|
|
}
|
|
template<typename RandomAccessIterator>
|
|
inline SPROUT_CONSTEXPR typename std::iterator_traits<RandomAccessIterator>::value_type
|
|
dft_element_gen_impl(
|
|
RandomAccessIterator first, RandomAccessIterator last,
|
|
typename std::iterator_traits<RandomAccessIterator>::value_type::value_type arg,
|
|
std::random_access_iterator_tag*
|
|
)
|
|
{
|
|
typedef typename std::iterator_traits<RandomAccessIterator>::value_type value_type;
|
|
return first == last ? value_type()
|
|
: sprout::detail::dft_element_gen_impl_ra(first, last, arg, NS_SSCRISK_CEL_OR_SPROUT::distance(first, last) / 2)
|
|
;
|
|
}
|
|
|
|
template<typename InputIterator>
|
|
inline SPROUT_CONSTEXPR typename std::iterator_traits<InputIterator>::value_type
|
|
dft_element_gen_impl_1(
|
|
InputIterator first, InputIterator last,
|
|
typename std::iterator_traits<InputIterator>::value_type::value_type arg,
|
|
typename std::iterator_traits<InputIterator>::difference_type k = 0,
|
|
typename std::iterator_traits<InputIterator>::value_type value
|
|
= typename std::iterator_traits<InputIterator>::value_type(),
|
|
typename std::iterator_traits<InputIterator>::value_type::value_type theta
|
|
= typename std::iterator_traits<InputIterator>::value_type::value_type()
|
|
)
|
|
{
|
|
typedef typename std::iterator_traits<InputIterator>::value_type value_type;
|
|
using sprout::cos;
|
|
using sprout::sin;
|
|
return first == last ? value
|
|
: value + sprout::detail::dft_element_gen_impl_1(
|
|
sprout::next(first), last,
|
|
arg,
|
|
k + 1,
|
|
*first * value_type(cos(theta), sin(theta)),
|
|
arg * (k + 1)
|
|
)
|
|
;
|
|
}
|
|
template<typename InputIterator>
|
|
inline SPROUT_CONSTEXPR typename std::iterator_traits<InputIterator>::value_type
|
|
dft_element_gen_impl(
|
|
InputIterator first, InputIterator last,
|
|
typename std::iterator_traits<InputIterator>::value_type::value_type arg,
|
|
void*
|
|
)
|
|
{
|
|
return sprout::detail::dft_element_gen_impl_1(first, last, arg);
|
|
}
|
|
|
|
template<typename InputIterator>
|
|
inline SPROUT_CONSTEXPR typename std::iterator_traits<InputIterator>::value_type
|
|
dft_element_gen(
|
|
InputIterator first, InputIterator last,
|
|
typename std::iterator_traits<InputIterator>::value_type::value_type arg,
|
|
typename std::iterator_traits<InputIterator>::difference_type k = 0,
|
|
typename std::iterator_traits<InputIterator>::value_type value
|
|
= typename std::iterator_traits<InputIterator>::value_type(),
|
|
typename std::iterator_traits<InputIterator>::value_type::value_type theta
|
|
= typename std::iterator_traits<InputIterator>::value_type::value_type()
|
|
)
|
|
{
|
|
typedef typename std::iterator_traits<InputIterator>::iterator_category* category;
|
|
return sprout::detail::dft_element_gen_impl(first, last, arg, category());
|
|
}
|
|
} // namespace detail
|
|
} // namespace sprout
|
|
|
|
#endif // #ifndef SPROUT_NUMERIC_DFT_DETAIL_DFT_ELEMENT_GEN_HPP
|