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pocketpy/3rd/numpy/include/xtensor/xoperation.hpp
Anurag Bhat 86b4fc623c
Merge numpy to pocketpy (#303) 
* Merge numpy to pocketpy

* Add CI

* Fix CI
2024-09-02 16:22:41 +08:00

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/***************************************************************************
* Copyright (c) Johan Mabille, Sylvain Corlay and Wolf Vollprecht *
* Copyright (c) QuantStack *
* *
* Distributed under the terms of the BSD 3-Clause License. *
* *
* The full license is in the file LICENSE, distributed with this software. *
****************************************************************************/
#ifndef XTENSOR_OPERATION_HPP
#define XTENSOR_OPERATION_HPP
#include <algorithm>
#include <functional>
#include <type_traits>
#include <xtl/xsequence.hpp>
#include "xfunction.hpp"
#include "xscalar.hpp"
#include "xstrided_view.hpp"
#include "xstrides.hpp"
namespace xt
{
/***********
* helpers *
***********/
#define UNARY_OPERATOR_FUNCTOR(NAME, OP) \
struct NAME \
{ \
template <class A1> \
constexpr auto operator()(const A1& arg) const \
{ \
return OP arg; \
} \
template <class B> \
constexpr auto simd_apply(const B& arg) const \
{ \
return OP arg; \
} \
}
#define DEFINE_COMPLEX_OVERLOAD(OP) \
template <class T1, class T2, XTL_REQUIRES(xtl::negation<std::is_same<T1, T2>>)> \
constexpr auto operator OP(const std::complex<T1>& arg1, const std::complex<T2>& arg2) \
{ \
using result_type = typename xtl::promote_type_t<std::complex<T1>, std::complex<T2>>; \
return (result_type(arg1) OP result_type(arg2)); \
} \
\
template <class T1, class T2, XTL_REQUIRES(xtl::negation<std::is_same<T1, T2>>)> \
constexpr auto operator OP(const T1& arg1, const std::complex<T2>& arg2) \
{ \
using result_type = typename xtl::promote_type_t<T1, std::complex<T2>>; \
return (result_type(arg1) OP result_type(arg2)); \
} \
\
template <class T1, class T2, XTL_REQUIRES(xtl::negation<std::is_same<T1, T2>>)> \
constexpr auto operator OP(const std::complex<T1>& arg1, const T2& arg2) \
{ \
using result_type = typename xtl::promote_type_t<std::complex<T1>, T2>; \
return (result_type(arg1) OP result_type(arg2)); \
}
#define BINARY_OPERATOR_FUNCTOR(NAME, OP) \
struct NAME \
{ \
template <class T1, class T2> \
constexpr auto operator()(T1&& arg1, T2&& arg2) const \
{ \
using xt::detail::operator OP; \
return (std::forward<T1>(arg1) OP std::forward<T2>(arg2)); \
} \
template <class B> \
constexpr auto simd_apply(const B& arg1, const B& arg2) const \
{ \
return (arg1 OP arg2); \
} \
}
namespace detail
{
DEFINE_COMPLEX_OVERLOAD(+);
DEFINE_COMPLEX_OVERLOAD(-);
DEFINE_COMPLEX_OVERLOAD(*);
DEFINE_COMPLEX_OVERLOAD(/);
DEFINE_COMPLEX_OVERLOAD(%);
DEFINE_COMPLEX_OVERLOAD(||);
DEFINE_COMPLEX_OVERLOAD(&&);
DEFINE_COMPLEX_OVERLOAD(|);
DEFINE_COMPLEX_OVERLOAD(&);
DEFINE_COMPLEX_OVERLOAD(^);
DEFINE_COMPLEX_OVERLOAD(<<);
DEFINE_COMPLEX_OVERLOAD(>>);
DEFINE_COMPLEX_OVERLOAD(<);
DEFINE_COMPLEX_OVERLOAD(<=);
DEFINE_COMPLEX_OVERLOAD(>);
DEFINE_COMPLEX_OVERLOAD(>=);
DEFINE_COMPLEX_OVERLOAD(==);
DEFINE_COMPLEX_OVERLOAD(!=);
UNARY_OPERATOR_FUNCTOR(identity, +);
UNARY_OPERATOR_FUNCTOR(negate, -);
BINARY_OPERATOR_FUNCTOR(plus, +);
BINARY_OPERATOR_FUNCTOR(minus, -);
BINARY_OPERATOR_FUNCTOR(multiplies, *);
BINARY_OPERATOR_FUNCTOR(divides, /);
BINARY_OPERATOR_FUNCTOR(modulus, %);
BINARY_OPERATOR_FUNCTOR(logical_or, ||);
BINARY_OPERATOR_FUNCTOR(logical_and, &&);
UNARY_OPERATOR_FUNCTOR(logical_not, !);
BINARY_OPERATOR_FUNCTOR(bitwise_or, |);
BINARY_OPERATOR_FUNCTOR(bitwise_and, &);
BINARY_OPERATOR_FUNCTOR(bitwise_xor, ^);
UNARY_OPERATOR_FUNCTOR(bitwise_not, ~);
BINARY_OPERATOR_FUNCTOR(left_shift, <<);
BINARY_OPERATOR_FUNCTOR(right_shift, >>);
BINARY_OPERATOR_FUNCTOR(less, <);
BINARY_OPERATOR_FUNCTOR(less_equal, <=);
BINARY_OPERATOR_FUNCTOR(greater, >);
BINARY_OPERATOR_FUNCTOR(greater_equal, >=);
BINARY_OPERATOR_FUNCTOR(equal_to, ==);
BINARY_OPERATOR_FUNCTOR(not_equal_to, !=);
struct conditional_ternary
{
template <class B>
using get_batch_bool = typename xt_simd::simd_traits<typename xt_simd::revert_simd_traits<B>::type>::bool_type;
template <class B, class A1, class A2>
constexpr auto operator()(const B& cond, const A1& v1, const A2& v2) const noexcept
{
return xtl::select(cond, v1, v2);
}
template <class B>
constexpr B simd_apply(const get_batch_bool<B>& t1, const B& t2, const B& t3) const noexcept
{
return xt_simd::select(t1, t2, t3);
}
};
template <class R>
struct cast
{
struct functor
{
using result_type = R;
template <class A1>
constexpr result_type operator()(const A1& arg) const
{
return static_cast<R>(arg);
}
// SIMD conversion disabled for now since it does not make sense
// in most of the cases
/*constexpr simd_result_type simd_apply(const simd_value_type& arg) const
{
return static_cast<R>(arg);
}*/
};
};
template <class Tag, class F, class... E>
struct select_xfunction_expression;
template <class F, class... E>
struct select_xfunction_expression<xtensor_expression_tag, F, E...>
{
using type = xfunction<F, E...>;
};
template <class F, class... E>
struct select_xfunction_expression<xoptional_expression_tag, F, E...>
{
using type = xfunction<F, E...>;
};
template <class Tag, class F, class... E>
using select_xfunction_expression_t = typename select_xfunction_expression<Tag, F, E...>::type;
template <class F, class... E>
struct xfunction_type
{
using expression_tag = xexpression_tag_t<E...>;
using functor_type = F;
using type = select_xfunction_expression_t<expression_tag, functor_type, const_xclosure_t<E>...>;
};
template <class F, class... E>
inline auto make_xfunction(E&&... e) noexcept
{
using function_type = xfunction_type<F, E...>;
using functor_type = typename function_type::functor_type;
using type = typename function_type::type;
return type(functor_type(), std::forward<E>(e)...);
}
// On MSVC, the second argument of enable_if_t is always evaluated, even if the condition is false.
// Wrapping the xfunction type in the xfunction_type metafunction avoids this evaluation when
// the condition is false, since it leads to a tricky bug preventing from using operator+ and
// operator- on vector and arrays iterators.
template <class F, class... E>
using xfunction_type_t = typename std::
enable_if_t<has_xexpression<std::decay_t<E>...>::value, xfunction_type<F, E...>>::type;
}
#undef UNARY_OPERATOR_FUNCTOR
#undef BINARY_OPERATOR_FUNCTOR
/*************
* operators *
*************/
/**
* @defgroup arithmetic_operators Arithmetic operators
*/
/**
* @ingroup arithmetic_operators
* @brief Identity
*
* Returns an \ref xfunction for the element-wise identity
* of \a e.
* @param e an \ref xexpression
* @return an \ref xfunction
*/
template <class E>
inline auto operator+(E&& e) noexcept -> detail::xfunction_type_t<detail::identity, E>
{
return detail::make_xfunction<detail::identity>(std::forward<E>(e));
}
/**
* @ingroup arithmetic_operators
* @brief Opposite
*
* Returns an \ref xfunction for the element-wise opposite
* of \a e.
* @param e an \ref xexpression
* @return an \ref xfunction
*/
template <class E>
inline auto operator-(E&& e) noexcept -> detail::xfunction_type_t<detail::negate, E>
{
return detail::make_xfunction<detail::negate>(std::forward<E>(e));
}
/**
* @ingroup arithmetic_operators
* @brief Addition
*
* Returns an \ref xfunction for the element-wise addition
* of \a e1 and \a e2.
* @param e1 an \ref xexpression or a scalar
* @param e2 an \ref xexpression or a scalar
* @return an \ref xfunction
*/
template <class E1, class E2>
inline auto operator+(E1&& e1, E2&& e2) noexcept -> detail::xfunction_type_t<detail::plus, E1, E2>
{
return detail::make_xfunction<detail::plus>(std::forward<E1>(e1), std::forward<E2>(e2));
}
/**
* @ingroup arithmetic_operators
* @brief Substraction
*
* Returns an \ref xfunction for the element-wise substraction
* of \a e2 to \a e1.
* @param e1 an \ref xexpression or a scalar
* @param e2 an \ref xexpression or a scalar
* @return an \ref xfunction
*/
template <class E1, class E2>
inline auto operator-(E1&& e1, E2&& e2) noexcept -> detail::xfunction_type_t<detail::minus, E1, E2>
{
return detail::make_xfunction<detail::minus>(std::forward<E1>(e1), std::forward<E2>(e2));
}
/**
* @ingroup arithmetic_operators
* @brief Multiplication
*
* Returns an \ref xfunction for the element-wise multiplication
* of \a e1 by \a e2.
* @param e1 an \ref xexpression or a scalar
* @param e2 an \ref xexpression or a scalar
* @return an \ref xfunction
*/
template <class E1, class E2>
inline auto operator*(E1&& e1, E2&& e2) noexcept -> detail::xfunction_type_t<detail::multiplies, E1, E2>
{
return detail::make_xfunction<detail::multiplies>(std::forward<E1>(e1), std::forward<E2>(e2));
}
/**
* @ingroup arithmetic_operators
* @brief Division
*
* Returns an \ref xfunction for the element-wise division
* of \a e1 by \a e2.
* @param e1 an \ref xexpression or a scalar
* @param e2 an \ref xexpression or a scalar
* @return an \ref xfunction
*/
template <class E1, class E2>
inline auto operator/(E1&& e1, E2&& e2) noexcept -> detail::xfunction_type_t<detail::divides, E1, E2>
{
return detail::make_xfunction<detail::divides>(std::forward<E1>(e1), std::forward<E2>(e2));
}
/**
* @ingroup arithmetic_operators
* @brief Modulus
*
* Returns an \ref xfunction for the element-wise modulus
* of \a e1 by \a e2.
* @param e1 an \ref xexpression or a scalar
* @param e2 an \ref xexpression or a scalar
* @return an \ref xfunction
*/
template <class E1, class E2>
inline auto operator%(E1&& e1, E2&& e2) noexcept -> detail::xfunction_type_t<detail::modulus, E1, E2>
{
return detail::make_xfunction<detail::modulus>(std::forward<E1>(e1), std::forward<E2>(e2));
}
/**
* @defgroup logical_operators Logical operators
*/
/**
* @ingroup logical_operators
* @brief Or
*
* Returns an \ref xfunction for the element-wise or
* of \a e1 and \a e2.
* @param e1 an \ref xexpression or a scalar
* @param e2 an \ref xexpression or a scalar
* @return an \ref xfunction
*/
template <class E1, class E2>
inline auto operator||(E1&& e1, E2&& e2) noexcept -> detail::xfunction_type_t<detail::logical_or, E1, E2>
{
return detail::make_xfunction<detail::logical_or>(std::forward<E1>(e1), std::forward<E2>(e2));
}
/**
* @ingroup logical_operators
* @brief And
*
* Returns an \ref xfunction for the element-wise and
* of \a e1 and \a e2.
* @param e1 an \ref xexpression or a scalar
* @param e2 an \ref xexpression or a scalar
* @return an \ref xfunction
*/
template <class E1, class E2>
inline auto operator&&(E1&& e1, E2&& e2) noexcept -> detail::xfunction_type_t<detail::logical_and, E1, E2>
{
return detail::make_xfunction<detail::logical_and>(std::forward<E1>(e1), std::forward<E2>(e2));
}
/**
* @ingroup logical_operators
* @brief Not
*
* Returns an \ref xfunction for the element-wise not
* of \a e.
* @param e an \ref xexpression
* @return an \ref xfunction
*/
template <class E>
inline auto operator!(E&& e) noexcept -> detail::xfunction_type_t<detail::logical_not, E>
{
return detail::make_xfunction<detail::logical_not>(std::forward<E>(e));
}
/**
* @defgroup bitwise_operators Bitwise operators
*/
/**
* @ingroup bitwise_operators
* @brief Bitwise and
*
* Returns an \ref xfunction for the element-wise bitwise and
* of \a e1 and \a e2.
* @param e1 an \ref xexpression or a scalar
* @param e2 an \ref xexpression or a scalar
* @return an \ref xfunction
*/
template <class E1, class E2>
inline auto operator&(E1&& e1, E2&& e2) noexcept -> detail::xfunction_type_t<detail::bitwise_and, E1, E2>
{
return detail::make_xfunction<detail::bitwise_and>(std::forward<E1>(e1), std::forward<E2>(e2));
}
/**
* @ingroup bitwise_operators
* @brief Bitwise or
*
* Returns an \ref xfunction for the element-wise bitwise or
* of \a e1 and \a e2.
* @param e1 an \ref xexpression or a scalar
* @param e2 an \ref xexpression or a scalar
* @return an \ref xfunction
*/
template <class E1, class E2>
inline auto operator|(E1&& e1, E2&& e2) noexcept -> detail::xfunction_type_t<detail::bitwise_or, E1, E2>
{
return detail::make_xfunction<detail::bitwise_or>(std::forward<E1>(e1), std::forward<E2>(e2));
}
/**
* @ingroup bitwise_operators
* @brief Bitwise xor
*
* Returns an \ref xfunction for the element-wise bitwise xor
* of \a e1 and \a e2.
* @param e1 an \ref xexpression or a scalar
* @param e2 an \ref xexpression or a scalar
* @return an \ref xfunction
*/
template <class E1, class E2>
inline auto operator^(E1&& e1, E2&& e2) noexcept -> detail::xfunction_type_t<detail::bitwise_xor, E1, E2>
{
return detail::make_xfunction<detail::bitwise_xor>(std::forward<E1>(e1), std::forward<E2>(e2));
}
/**
* @ingroup bitwise_operators
* @brief Bitwise not
*
* Returns an \ref xfunction for the element-wise bitwise not
* of \a e.
* @param e an \ref xexpression
* @return an \ref xfunction
*/
template <class E>
inline auto operator~(E&& e) noexcept -> detail::xfunction_type_t<detail::bitwise_not, E>
{
return detail::make_xfunction<detail::bitwise_not>(std::forward<E>(e));
}
/**
* @ingroup bitwise_operators
* @brief Bitwise left shift
*
* Returns an \ref xfunction for the element-wise bitwise left shift of e1
* by e2.
* @param e1 an \ref xexpression
* @param e2 an \ref xexpression
* @return an \ref xfunction
*/
template <class E1, class E2>
inline auto left_shift(E1&& e1, E2&& e2) noexcept -> detail::xfunction_type_t<detail::left_shift, E1, E2>
{
return detail::make_xfunction<detail::left_shift>(std::forward<E1>(e1), std::forward<E2>(e2));
}
/**
* @ingroup bitwise_operators
* @brief Bitwise left shift
*
* Returns an \ref xfunction for the element-wise bitwise left shift of e1
* by e2.
* @param e1 an \ref xexpression
* @param e2 an \ref xexpression
* @return an \ref xfunction
*/
template <class E1, class E2>
inline auto right_shift(E1&& e1, E2&& e2) noexcept -> detail::xfunction_type_t<detail::right_shift, E1, E2>
{
return detail::make_xfunction<detail::right_shift>(std::forward<E1>(e1), std::forward<E2>(e2));
}
namespace detail
{
// Shift operator is not available for all the types, so the xfunction type instantiation
// has to be delayed, enable_if_t is not sufficient
template <class F, class E1, class E2>
struct shift_function_getter
{
using type = xfunction_type_t<F, E1, E2>;
};
template <bool B, class T>
struct eval_enable_if
{
using type = typename T::type;
};
template <class T>
struct eval_enable_if<false, T>
{
};
template <bool B, class T>
using eval_enable_if_t = typename eval_enable_if<B, T>::type;
template <class F, class E1, class E2>
using shift_return_type_t = eval_enable_if_t<
is_xexpression<std::decay_t<E1>>::value,
shift_function_getter<F, E1, E2>>;
}
/**
* @ingroup bitwise_operators
* @brief Bitwise left shift
*
* Returns an \ref xfunction for the element-wise bitwise left shift of e1
* by e2.
* @param e1 an \ref xexpression
* @param e2 an \ref xexpression
* @return an \ref xfunction
* @sa left_shift
*/
template <class E1, class E2>
inline auto operator<<(E1&& e1, E2&& e2) noexcept
-> detail::shift_return_type_t<detail::left_shift, E1, E2>
{
return left_shift(std::forward<E1>(e1), std::forward<E2>(e2));
}
/**
* @ingroup bitwise_operators
* @brief Bitwise right shift
*
* Returns an \ref xfunction for the element-wise bitwise right shift of e1
* by e2.
* @param e1 an \ref xexpression
* @param e2 an \ref xexpression
* @return an \ref xfunction
* @sa right_shift
*/
template <class E1, class E2>
inline auto operator>>(E1&& e1, E2&& e2) -> detail::shift_return_type_t<detail::right_shift, E1, E2>
{
return right_shift(std::forward<E1>(e1), std::forward<E2>(e2));
}
/**
* @defgroup comparison_operators Comparison operators
*/
/**
* @ingroup comparison_operators
* @brief Lesser than
*
* Returns an \ref xfunction for the element-wise
* lesser than comparison of \a e1 and \a e2.
* @param e1 an \ref xexpression or a scalar
* @param e2 an \ref xexpression or a scalar
* @return an \ref xfunction
*/
template <class E1, class E2>
inline auto operator<(E1&& e1, E2&& e2) noexcept -> detail::xfunction_type_t<detail::less, E1, E2>
{
return detail::make_xfunction<detail::less>(std::forward<E1>(e1), std::forward<E2>(e2));
}
/**
* @ingroup comparison_operators
* @brief Lesser or equal
*
* Returns an \ref xfunction for the element-wise
* lesser or equal comparison of \a e1 and \a e2.
* @param e1 an \ref xexpression or a scalar
* @param e2 an \ref xexpression or a scalar
* @return an \ref xfunction
*/
template <class E1, class E2>
inline auto operator<=(E1&& e1, E2&& e2) noexcept -> detail::xfunction_type_t<detail::less_equal, E1, E2>
{
return detail::make_xfunction<detail::less_equal>(std::forward<E1>(e1), std::forward<E2>(e2));
}
/**
* @ingroup comparison_operators
* @brief Greater than
*
* Returns an \ref xfunction for the element-wise
* greater than comparison of \a e1 and \a e2.
* @param e1 an \ref xexpression or a scalar
* @param e2 an \ref xexpression or a scalar
* @return an \ref xfunction
*/
template <class E1, class E2>
inline auto operator>(E1&& e1, E2&& e2) noexcept -> detail::xfunction_type_t<detail::greater, E1, E2>
{
return detail::make_xfunction<detail::greater>(std::forward<E1>(e1), std::forward<E2>(e2));
}
/**
* @ingroup comparison_operators
* @brief Greater or equal
*
* Returns an \ref xfunction for the element-wise
* greater or equal comparison of \a e1 and \a e2.
* @param e1 an \ref xexpression or a scalar
* @param e2 an \ref xexpression or a scalar
* @return an \ref xfunction
*/
template <class E1, class E2>
inline auto operator>=(E1&& e1, E2&& e2) noexcept
-> detail::xfunction_type_t<detail::greater_equal, E1, E2>
{
return detail::make_xfunction<detail::greater_equal>(std::forward<E1>(e1), std::forward<E2>(e2));
}
/**
* @ingroup comparison_operators
* @brief Equality
*
* Returns true if \a e1 and \a e2 have the same shape
* and hold the same values. Unlike other comparison
* operators, this does not return an \ref xfunction.
* @param e1 an \ref xexpression or a scalar
* @param e2 an \ref xexpression or a scalar
* @return a boolean
*/
template <class E1, class E2>
inline std::enable_if_t<xoptional_comparable<E1, E2>::value, bool>
operator==(const xexpression<E1>& e1, const xexpression<E2>& e2)
{
const E1& de1 = e1.derived_cast();
const E2& de2 = e2.derived_cast();
bool res = de1.dimension() == de2.dimension()
&& std::equal(de1.shape().begin(), de1.shape().end(), de2.shape().begin());
auto iter1 = de1.begin();
auto iter2 = de2.begin();
auto iter_end = de1.end();
while (res && iter1 != iter_end)
{
res = (*iter1++ == *iter2++);
}
return res;
}
/**
* @ingroup comparison_operators
* @brief Inequality
*
* Returns true if \a e1 and \a e2 have different shapes
* or hold the different values. Unlike other comparison
* operators, this does not return an \ref xfunction.
* @param e1 an \ref xexpression or a scalar
* @param e2 an \ref xexpression or a scalar
* @return a boolean
*/
template <class E1, class E2>
inline bool operator!=(const xexpression<E1>& e1, const xexpression<E2>& e2)
{
return !(e1 == e2);
}
/**
* @ingroup comparison_operators
* @brief Element-wise equality
*
* Returns an \ref xfunction for the element-wise
* equality of \a e1 and \a e2.
* @param e1 an \ref xexpression or a scalar
* @param e2 an \ref xexpression or a scalar
* @return an \ref xfunction
*/
template <class E1, class E2>
inline auto equal(E1&& e1, E2&& e2) noexcept -> detail::xfunction_type_t<detail::equal_to, E1, E2>
{
return detail::make_xfunction<detail::equal_to>(std::forward<E1>(e1), std::forward<E2>(e2));
}
/**
* @ingroup comparison_operators
* @brief Element-wise inequality
*
* Returns an \ref xfunction for the element-wise
* inequality of \a e1 and \a e2.
* @param e1 an \ref xexpression or a scalar
* @param e2 an \ref xexpression or a scalar
* @return an \ref xfunction
*/
template <class E1, class E2>
inline auto not_equal(E1&& e1, E2&& e2) noexcept -> detail::xfunction_type_t<detail::not_equal_to, E1, E2>
{
return detail::make_xfunction<detail::not_equal_to>(std::forward<E1>(e1), std::forward<E2>(e2));
}
/**
* @ingroup comparison_operators
* @brief Lesser than
*
* Returns an \ref xfunction for the element-wise
* lesser than comparison of \a e1 and \a e2. This
* function is equivalent to operator<(E1&&, E2&&).
* @param e1 an \ref xexpression or a scalar
* @param e2 an \ref xexpression or a scalar
* @return an \ref xfunction
*/
template <class E1, class E2>
inline auto less(E1&& e1, E2&& e2) noexcept -> decltype(std::forward<E1>(e1) < std::forward<E2>(e2))
{
return std::forward<E1>(e1) < std::forward<E2>(e2);
}
/**
* @ingroup comparison_operators
* @brief Lesser or equal
*
* Returns an \ref xfunction for the element-wise
* lesser or equal comparison of \a e1 and \a e2. This
* function is equivalent to operator<=(E1&&, E2&&).
* @param e1 an \ref xexpression or a scalar
* @param e2 an \ref xexpression or a scalar
* @return an \ref xfunction
*/
template <class E1, class E2>
inline auto less_equal(E1&& e1, E2&& e2) noexcept -> decltype(std::forward<E1>(e1) <= std::forward<E2>(e2))
{
return std::forward<E1>(e1) <= std::forward<E2>(e2);
}
/**
* @ingroup comparison_operators
* @brief Greater than
*
* Returns an \ref xfunction for the element-wise
* greater than comparison of \a e1 and \a e2. This
* function is equivalent to operator>(E1&&, E2&&).
* @param e1 an \ref xexpression or a scalar
* @param e2 an \ref xexpression or a scalar
* @return an \ref xfunction
*/
template <class E1, class E2>
inline auto greater(E1&& e1, E2&& e2) noexcept -> decltype(std::forward<E1>(e1) > std::forward<E2>(e2))
{
return std::forward<E1>(e1) > std::forward<E2>(e2);
}
/**
* @ingroup comparison_operators
* @brief Greater or equal
*
* Returns an \ref xfunction for the element-wise
* greater or equal comparison of \a e1 and \a e2.
* This function is equivalent to operator>=(E1&&, E2&&).
* @param e1 an \ref xexpression or a scalar
* @param e2 an \ref xexpression or a scalar
* @return an \ref xfunction
*/
template <class E1, class E2>
inline auto greater_equal(E1&& e1, E2&& e2) noexcept
-> decltype(std::forward<E1>(e1) >= std::forward<E2>(e2))
{
return std::forward<E1>(e1) >= std::forward<E2>(e2);
}
/**
* @ingroup logical_operators
* @brief Ternary selection
*
* Returns an \ref xfunction for the element-wise
* ternary selection (i.e. operator ? :) of \a e1,
* \a e2 and \a e3.
* @param e1 a boolean \ref xexpression
* @param e2 an \ref xexpression or a scalar
* @param e3 an \ref xexpression or a scalar
* @return an \ref xfunction
*/
template <class E1, class E2, class E3>
inline auto where(E1&& e1, E2&& e2, E3&& e3) noexcept
-> detail::xfunction_type_t<detail::conditional_ternary, E1, E2, E3>
{
return detail::make_xfunction<detail::conditional_ternary>(
std::forward<E1>(e1),
std::forward<E2>(e2),
std::forward<E3>(e3)
);
}
namespace detail
{
template <layout_type L>
struct next_idx_impl;
template <>
struct next_idx_impl<layout_type::row_major>
{
template <class S, class I>
inline auto operator()(const S& shape, I& idx)
{
for (std::size_t j = shape.size(); j > 0; --j)
{
std::size_t i = j - 1;
if (idx[i] >= shape[i] - 1)
{
idx[i] = 0;
}
else
{
idx[i]++;
return idx;
}
}
// return empty index, happens at last iteration step, but remains unused
return I();
}
};
template <>
struct next_idx_impl<layout_type::column_major>
{
template <class S, class I>
inline auto operator()(const S& shape, I& idx)
{
for (std::size_t i = 0; i < shape.size(); ++i)
{
if (idx[i] >= shape[i] - 1)
{
idx[i] = 0;
}
else
{
idx[i]++;
return idx;
}
}
// return empty index, happens at last iteration step, but remains unused
return I();
}
};
template <layout_type L = XTENSOR_DEFAULT_TRAVERSAL, class S, class I>
inline auto next_idx(const S& shape, I& idx)
{
next_idx_impl<L> nii;
return nii(shape, idx);
}
}
/**
* @ingroup logical_operators
* @brief return vector of indices where T is not zero
*
* @param arr input array
* @return vector of vectors, one for each dimension of arr, containing
* the indices of the non-zero elements in that dimension
*/
template <class T>
inline auto nonzero(const T& arr)
{
auto shape = arr.shape();
using index_type = xindex_type_t<typename T::shape_type>;
using size_type = typename T::size_type;
auto idx = xtl::make_sequence<index_type>(arr.dimension(), 0);
std::vector<std::vector<size_type>> indices(arr.dimension());
size_type total_size = compute_size(shape);
for (size_type i = 0; i < total_size; i++, detail::next_idx(shape, idx))
{
if (arr.element(std::begin(idx), std::end(idx)))
{
for (std::size_t n = 0; n < indices.size(); ++n)
{
indices.at(n).push_back(idx[n]);
}
}
}
return indices;
}
/**
* @ingroup logical_operators
* @brief return vector of indices where condition is true
* (equivalent to \a nonzero(condition))
*
* @param condition input array
* @return vector of \a index_types where condition is not equal to zero
*/
template <class T>
inline auto where(const T& condition)
{
return nonzero(condition);
}
/**
* @ingroup logical_operators
* @brief return vector of indices where arr is not zero
*
* @tparam L the traversal order
* @param arr input array
* @return vector of index_types where arr is not equal to zero (use `xt::from_indices` to convert)
*
* @sa xt::from_indices
*/
template <layout_type L = XTENSOR_DEFAULT_TRAVERSAL, class T>
inline auto argwhere(const T& arr)
{
auto shape = arr.shape();
using index_type = xindex_type_t<typename T::shape_type>;
using size_type = typename T::size_type;
auto idx = xtl::make_sequence<index_type>(arr.dimension(), 0);
std::vector<index_type> indices;
size_type total_size = compute_size(shape);
for (size_type i = 0; i < total_size; i++, detail::next_idx<L>(shape, idx))
{
if (arr.element(std::begin(idx), std::end(idx)))
{
indices.push_back(idx);
}
}
return indices;
}
/**
* @ingroup logical_operators
* @brief Any
*
* Returns true if any of the values of \a e is truthy,
* false otherwise.
* @param e an \ref xexpression
* @return a boolean
*/
template <class E>
inline bool any(E&& e)
{
using xtype = std::decay_t<E>;
using value_type = typename xtype::value_type;
return std::any_of(
e.cbegin(),
e.cend(),
[](const value_type& el)
{
return el;
}
);
}
/**
* @ingroup logical_operators
* @brief Any
*
* Returns true if all of the values of \a e are truthy,
* false otherwise.
* @param e an \ref xexpression
* @return a boolean
*/
template <class E>
inline bool all(E&& e)
{
using xtype = std::decay_t<E>;
using value_type = typename xtype::value_type;
return std::all_of(
e.cbegin(),
e.cend(),
[](const value_type& el)
{
return el;
}
);
}
/**
* @defgroup casting_operators Casting operators
*/
/**
* @ingroup casting_operators
* @brief Element-wise ``static_cast``.
*
* Returns an \ref xfunction for the element-wise
* static_cast of \a e to type R.
*
* @param e an \ref xexpression or a scalar
* @return an \ref xfunction
*/
template <class R, class E>
inline auto cast(E&& e) noexcept -> detail::xfunction_type_t<typename detail::cast<R>::functor, E>
{
return detail::make_xfunction<typename detail::cast<R>::functor>(std::forward<E>(e));
}
}
#endif
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