Как изменить содержимое zip-итератора - PullRequest
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Как изменить содержимое zip-итератора

0 голосов
/ 22 ноября 2018

У меня есть XYZ локации 1000 очков.Мне нужно преобразовать каждый из них с помощью матрицы.Чтобы начать с более простой задачи, я пытаюсь умножить каждую точку на постоянную.Также я беру только три очка к примеру.Я использую thrust :: zip_iterator для упаковки XYZ и использую функтор и операцию преобразования для изменения XYZ.

Мой код такой же, как показано ниже, однако он выдает ошибку компиляции.Функтор modify_tuple компилируется нормально.Но когда он используется в операции преобразования, я получаю много ошибок. Мой вопрос: как изменить содержимое zip-итератора?Или Как применить функтор к кортежу типа XYZ для всех точек, использующих тягу.Есть какой-нибудь другой алгоритм тяги, который я могу использовать? 

#include <thrust/transform.h>
#include <thrust/iterator/zip_iterator.h>
#include <thrust/execution_policy.h>

typedef thrust::tuple<float,float,float> Float3;

struct modify_tuple
{
    int _factor;
    modify_tuple(int factor) : _factor(factor) { }

    __host__ __device__ Float3 operator()(Float3&a) const
    {
        Float3 b=thrust::make_tuple(_factor*thrust::get<0>(a), _factor*thrust::get<1>(a), _factor*thrust::get<2>(a));      

        return b;
    }
};

int main(void)
{
    thrust::device_vector<float> X(3);
    thrust::device_vector<float> Y(3);
    thrust::device_vector<float> Z(3);

    X[0]=0,    X[0]=1,    X[0]=2;
    Y[0]=4,    Y[0]=5,    Y[0]=6;
    Z[0]=7,    Z[0]=8,    Z[0]=9;

    typedef thrust::device_vector<float>::iterator                     FloatIterator;
    typedef thrust::tuple<FloatIterator, FloatIterator, FloatIterator> FloatIteratorTuple;
    typedef thrust::zip_iterator<FloatIteratorTuple>                   Float3Iterator;

    Float3Iterator P_first = thrust::make_zip_iterator(make_tuple(X.begin(), Y.begin(), Z.begin()));
    Float3Iterator P_last  = thrust::make_zip_iterator(make_tuple(X.end(), Y.end(), Z.end()));

// This line gives errors
    thrust::transform(thrust::device, P_first, P_last, P_first, modify_tuple(2));  

    return 0;
}

Ошибки, найденные во время компиляции: 

/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/detail/internal_functional.h(322): error: function "modify_tuple::operator()" cannot be called with the given argument list
            argument types are: (thrust::detail::tuple_of_iterator_references<float &, float &, float &, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>)
            object type is: modify_tuple
          detected during:
            instantiation of "thrust::detail::enable_if_non_const_reference_or_tuple_of_iterator_references<thrust::tuple_element<1, Tuple>::type>::type thrust::detail::unary_transform_functor<UnaryFunction>::operator()(Tuple) [with UnaryFunction=modify_tuple, Tuple=thrust::detail::tuple_of_iterator_references<thrust::detail::tuple_of_iterator_references<float &, float &, float &, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>, thrust::detail::tuple_of_iterator_references<float &, float &, float &, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>]" 
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/detail/function.h(60): here
            instantiation of "Result thrust::detail::wrapped_function<Function, Result>::operator()(const Argument &) const [with Function=thrust::detail::unary_transform_functor<modify_tuple>, Result=void, Argument=thrust::detail::tuple_of_iterator_references<thrust::detail::tuple_of_iterator_references<thrust::device_reference<float>, thrust::device_reference<float>, thrust::device_reference<float>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>, thrust::detail::tuple_of_iterator_references<thrust::device_reference<float>, thrust::device_reference<float>, thrust::device_reference<float>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>]" 
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/system/cuda/detail/for_each.inl(57): here
            instantiation of "void thrust::system::cuda::detail::for_each_n_detail::for_each_kernel::operator()(thrust::system::cuda::detail::bulk_::parallel_group<thrust::system::cuda::detail::bulk_::concurrent_group<thrust::system::cuda::detail::bulk_::agent<1UL>, 0UL>, 0UL> &, Iterator, Function, Size) [with Iterator=thrust::zip_iterator<thrust::tuple<thrust::zip_iterator<thrust::tuple<thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, thrust::zip_iterator<thrust::tuple<thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, Function=thrust::detail::wrapped_function<thrust::detail::unary_transform_functor<modify_tuple>, void>, Size=unsigned int]" 
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/system/cuda/detail/bulk/detail/apply_from_tuple.hpp(71): here
            instantiation of "void thrust::system::cuda::detail::bulk_::detail::apply_from_tuple(Function, const thrust::tuple<Arg1, Arg2, Arg3, Arg4, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type> &) [with Function=thrust::system::cuda::detail::for_each_n_detail::for_each_kernel, Arg1=thrust::system::cuda::detail::bulk_::parallel_group<thrust::system::cuda::detail::bulk_::concurrent_group<thrust::system::cuda::detail::bulk_::agent<1UL>, 0UL>, 0UL> &, Arg2=thrust::zip_iterator<thrust::tuple<thrust::zip_iterator<thrust::tuple<thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, thrust::zip_iterator<thrust::tuple<thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, Arg3=thrust::detail::wrapped_function<thrust::detail::unary_transform_functor<modify_tuple>, void>, Arg4=unsigned int]" 
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/system/cuda/detail/bulk/detail/closure.hpp(50): here
            instantiation of "void thrust::system::cuda::detail::bulk_::detail::closure<Function, Tuple>::operator()() [with Function=thrust::system::cuda::detail::for_each_n_detail::for_each_kernel, Tuple=thrust::tuple<thrust::system::cuda::detail::bulk_::parallel_group<thrust::system::cuda::detail::bulk_::concurrent_group<thrust::system::cuda::detail::bulk_::agent<1UL>, 0UL>, 0UL> &, thrust::zip_iterator<thrust::tuple<thrust::zip_iterator<thrust::tuple<thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, thrust::zip_iterator<thrust::tuple<thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, thrust::detail::wrapped_function<thrust::detail::unary_transform_functor<modify_tuple>, void>, unsigned int, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>]" 
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/system/cuda/detail/bulk/detail/cuda_task.hpp(58): here
            [ 8 instantiation contexts not shown ]
            instantiation of "RandomAccessIterator thrust::system::cuda::detail::for_each_n(thrust::system::cuda::detail::execution_policy<DerivedPolicy> &, RandomAccessIterator, Size, UnaryFunction) [with DerivedPolicy=thrust::system::cuda::detail::par_t, RandomAccessIterator=thrust::zip_iterator<thrust::tuple<thrust::zip_iterator<thrust::tuple<thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, thrust::zip_iterator<thrust::tuple<thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, Size=signed long, UnaryFunction=thrust::detail::unary_transform_functor<modify_tuple>]" 
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/system/cuda/detail/for_each.inl(173): here
            instantiation of "RandomAccessIterator thrust::system::cuda::detail::for_each(thrust::system::cuda::detail::execution_policy<DerivedPolicy> &, RandomAccessIterator, RandomAccessIterator, UnaryFunction) [with DerivedPolicy=thrust::system::cuda::detail::par_t, RandomAccessIterator=thrust::zip_iterator<thrust::tuple<thrust::zip_iterator<thrust::tuple<thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, thrust::zip_iterator<thrust::tuple<thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, UnaryFunction=thrust::detail::unary_transform_functor<modify_tuple>]" 
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/detail/for_each.inl(44): here
            instantiation of "InputIterator thrust::for_each(const thrust::detail::execution_policy_base<DerivedPolicy> &, InputIterator, InputIterator, UnaryFunction) [with DerivedPolicy=thrust::system::cuda::detail::par_t, InputIterator=thrust::zip_iterator<thrust::tuple<thrust::zip_iterator<thrust::tuple<thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, thrust::zip_iterator<thrust::tuple<thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, UnaryFunction=thrust::detail::unary_transform_functor<modify_tuple>]" 
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/system/detail/generic/transform.inl(57): here
            instantiation of "OutputIterator thrust::system::detail::generic::transform(thrust::execution_policy<DerivedPolicy> &, InputIterator, InputIterator, OutputIterator, UnaryFunction) [with DerivedPolicy=thrust::system::cuda::detail::par_t, InputIterator=thrust::zip_iterator<thrust::tuple<thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, OutputIterator=thrust::zip_iterator<thrust::tuple<thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, UnaryFunction=modify_tuple]" 
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/detail/transform.inl(44): here
            instantiation of "OutputIterator thrust::transform(const thrust::detail::execution_policy_base<DerivedPolicy> &, InputIterator, InputIterator, OutputIterator, UnaryFunction) [with DerivedPolicy=thrust::system::cuda::detail::par_t, InputIterator=thrust::zip_iterator<thrust::tuple<thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, OutputIterator=thrust::zip_iterator<thrust::tuple<thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, UnaryFunction=modify_tuple]" 
modify_zip_iterator.cu(38): here

1 Ответ

0 голосов
/ 23 ноября 2018

Получение типов функторов, соответствующих типам, передаваемым и требующимся для толчка, иногда может быть сложным.Вот один из возможных подходов с использованием шаблонов, позволяющих компилятору определять точный необходимый тип: 

$ cat t334.cu
#include <thrust/transform.h>
#include <thrust/iterator/zip_iterator.h>
#include <thrust/execution_policy.h>
#include <iostream>
#include <thrust/copy.h>

struct modify_tuple
{
    int _factor;
    modify_tuple(int factor) : _factor(factor) { }
template <typename T>
    __host__ __device__ thrust::tuple<float,float,float> operator()(const T a) const
    {
        thrust::tuple<float,float,float>  res = a;
        thrust::get<0>(res) *= _factor;
        thrust::get<1>(res) *= _factor;
        thrust::get<2>(res) *= _factor;
        return res;
    }
};

int main(void)
{
    thrust::device_vector<float> X(3);
    thrust::device_vector<float> Y(3);
    thrust::device_vector<float> Z(3);
    thrust::device_vector<float> RX(3);
    thrust::device_vector<float> RY(3);
    thrust::device_vector<float> RZ(3);

    X[0]=0,    X[1]=1,    X[2]=2;
    Y[0]=4,    Y[1]=5,    Y[2]=6;
    Z[0]=7,    Z[1]=8,    Z[2]=9;

    thrust::copy_n(X.begin(), 3, std::ostream_iterator<float>(std::cout, ","));
    std::cout << std::endl;
    thrust::copy_n(Y.begin(), 3, std::ostream_iterator<float>(std::cout, ","));
    std::cout << std::endl;
    thrust::copy_n(Z.begin(), 3, std::ostream_iterator<float>(std::cout, ","));
    std::cout << std::endl;
    thrust::transform(thrust::device, thrust::make_zip_iterator(thrust::make_tuple(X.begin(), Y.begin(), Z.begin())),thrust::make_zip_iterator(thrust::make_tuple(X.end(), Y.end(), Z.end())), thrust::make_zip_iterator(thrust::make_tuple(RX.begin(), RY.begin(), RZ.begin())), modify_tuple(2));
    thrust::copy_n(X.begin(), 3, std::ostream_iterator<float>(std::cout, ","));
    std::cout << std::endl;
    thrust::copy_n(Y.begin(), 3, std::ostream_iterator<float>(std::cout, ","));
    std::cout << std::endl;
    thrust::copy_n(Z.begin(), 3, std::ostream_iterator<float>(std::cout, ","));
    std::cout << std::endl;
    thrust::copy_n(RX.begin(), 3, std::ostream_iterator<float>(std::cout, ","));
    std::cout << std::endl;
    thrust::copy_n(RY.begin(), 3, std::ostream_iterator<float>(std::cout, ","));
    std::cout << std::endl;
    thrust::copy_n(RZ.begin(), 3, std::ostream_iterator<float>(std::cout, ","));
    std::cout << std::endl;

    return 0;
}
$ nvcc -o t334 t334.cu
$ ./t334
0,1,2,
4,5,6,
7,8,9,
0,1,2,
4,5,6,
7,8,9,
0,2,4,
8,10,12,
14,16,18,
$

Точный базовый тип, передаваемый функтору, выглядит как ссылка на кортеж итератора, тогда как возвращаемый типявляется обычным кортежем float значений.

Обратите внимание, что можно изменить a непосредственно в функторе.Обычно кажется, что a передается по значению функтору, но в этом случае thrust использует ссылки на кортеж итератора, и поэтому побочный эффект изменения a в функторе заключается в том, что он изменитфактические значения вектора тяги, передаваемые функтору (т. е. исходный вектор (ы)).Поэтому в вышеприведенном коде я выбрал реализацию, которая этого избегает, однако в случае вашего исходного кода очевидно, что вы намеревались выполнить модификацию исходных векторов на месте.Следовательно, функтор может быть упрощен для непосредственного изменения a, если это необходимо.

...