thrust::inner_product

Overloads

inner_product(exec, first1, last1, first2, init)

template<typename DerivedPolicy, typename InputIterator1, typename InputIterator2, typename OutputType>
OutputType thrust::inner_product(

const thrust::detail::execution_policy_base<DerivedPolicy> &exec,

InputIterator1 first1,

InputIterator1 last1,

InputIterator2 first2,

OutputType init

)

inner_product calculates an inner product of the ranges [first1, last1) and [first2, first2 + (last1 - first1)).

Specifically, this version of inner_product computes the sum init + (*first1 * *first2) + (*(first1+1) * *(first2+1)) + ...

The algorithm’s execution is parallelized as determined by exec.

The following code demonstrates how to use inner_product to compute the dot product of two vectors using the thrust::host execution policy for parallelization.

#include <thrust/inner_product.h>
#include <thrust/execution_policy.h>
...
float vec1[3] = {1.0f, 2.0f, 5.0f};
float vec2[3] = {4.0f, 1.0f, 5.0f};

float result = thrust::inner_product(thrust::host, vec1, vec1 + 3, vec2, 0.0f);

// result == 31.0f

See also

https://en.cppreference.com/w/cpp/algorithm/inner_product

Parameters:

• exec – The execution policy to use for parallelization.

• first1 – The beginning of the first sequence.

• last1 – The end of the first sequence.

• first2 – The beginning of the second sequence.

• init – Initial value of the result.

Template Parameters:

• DerivedPolicy – The name of the derived execution policy.

• InputIterator1 – is a model of Input Iterator,

• InputIterator2 – is a model of Input Iterator,

• OutputType – is a model of Assignable, and if x is an object of type OutputType, and y is an object of InputIterator1's value_type, and z is an object of InputIterator2's value_type, then x + y * z is defined and is convertible to OutputType.

Returns:

The inner product of sequences [first1, last1) and [first2, last2) plus init.

inner_product(first1, last1, first2, init)

template<typename InputIterator1, typename InputIterator2, typename OutputType>
OutputType thrust::inner_product(

InputIterator1 first1,

InputIterator1 last1,

InputIterator2 first2,

OutputType init

)

inner_product calculates an inner product of the ranges [first1, last1) and [first2, first2 + (last1 - first1)).

Specifically, this version of inner_product computes the sum init + (*first1 * *first2) + (*(first1+1) * *(first2+1)) + ...

Unlike the C++ Standard Template Library function std::inner_product, this version offers no guarantee on order of execution.

The following code demonstrates how to use inner_product to compute the dot product of two vectors.

#include <thrust/inner_product.h>
...
float vec1[3] = {1.0f, 2.0f, 5.0f};
float vec2[3] = {4.0f, 1.0f, 5.0f};

float result = thrust::inner_product(vec1, vec1 + 3, vec2, 0.0f);

// result == 31.0f

See also

https://en.cppreference.com/w/cpp/algorithm/inner_product

Parameters:

• first1 – The beginning of the first sequence.

• last1 – The end of the first sequence.

• first2 – The beginning of the second sequence.

• init – Initial value of the result.

Template Parameters:

• InputIterator1 – is a model of Input Iterator,

• InputIterator2 – is a model of Input Iterator,

• OutputType – is a model of Assignable, and if x is an object of type OutputType, and y is an object of InputIterator1's value_type, and z is an object of InputIterator2's value_type, then x + y * z is defined and is convertible to OutputType.

Returns:

The inner product of sequences [first1, last1) and [first2, last2) plus init.

inner_product(exec, first1, last1, first2, init, binary_op1, binary_op2)

template<typename DerivedPolicy, typename InputIterator1, typename InputIterator2, typename OutputType, typename BinaryFunction1, typename BinaryFunction2>
OutputType thrust::inner_product(

const thrust::detail::execution_policy_base<DerivedPolicy> &exec,

InputIterator1 first1,

InputIterator1 last1,

InputIterator2 first2,

OutputType init,

BinaryFunction1 binary_op1,

BinaryFunction2 binary_op2

)

inner_product calculates an inner product of the ranges [first1, last1) and [first2, first2 + (last1 - first1)).

This version of inner_product is identical to the first, except that is uses two user-supplied function objects instead of operator+ and operator*.

Specifically, this version of inner_product computes the sum binary_op1( init, binary_op2(*first1, *first2) ), ...

The algorithm’s execution is parallelized as determined by exec.

#include <thrust/inner_product.h>
#include <thrust/execution_policy.h>
...
float vec1[3] = {1.0f, 2.0f, 5.0f};
float vec2[3] = {4.0f, 1.0f, 5.0f};

float init = 0.0f;
::cuda::std::plus<float>       binary_op1;
::cuda::std::multiplies<float> binary_op2;

float result = thrust::inner_product(thrust::host, vec1, vec1 + 3, vec2, init, binary_op1, binary_op2);

// result == 31.0f

See also

https://en.cppreference.com/w/cpp/algorithm/inner_product

Parameters:

• exec – The execution policy to use for parallelization.

• first1 – The beginning of the first sequence.

• last1 – The end of the first sequence.

• first2 – The beginning of the second sequence.

• init – Initial value of the result.

• binary_op1 – Generalized addition operation.

• binary_op2 – Generalized multiplication operation.

Template Parameters:

• DerivedPolicy – The name of the derived execution policy.

• InputIterator1 – is a model of Input Iterator, and InputIterator1's value_type is convertible to BinaryFunction2's first argument type.

• InputIterator2 – is a model of Input Iterator. and InputIterator2's value_type is convertible to BinaryFunction2's second argument type.

• OutputType – is a model of Assignable, and OutputType is convertible to BinaryFunction1's first argument type.

• BinaryFunction1 – The function’s return type must be convertible to OutputType.

• BinaryFunction2 – The function’s return type must be convertible to BinaryFunction1's second argument type.

Returns:

The inner product of sequences [first1, last1) and [first2, last2).

inner_product(first1, last1, first2, init, binary_op1, binary_op2)

template<typename InputIterator1, typename InputIterator2, typename OutputType, typename BinaryFunction1, typename BinaryFunction2>
OutputType thrust::inner_product(

InputIterator1 first1,

InputIterator1 last1,

InputIterator2 first2,

OutputType init,

BinaryFunction1 binary_op1,

BinaryFunction2 binary_op2

)

inner_product calculates an inner product of the ranges [first1, last1) and [first2, first2 + (last1 - first1)).

This version of inner_product is identical to the first, except that is uses two user-supplied function objects instead of operator+ and operator*.

Specifically, this version of inner_product computes the sum binary_op1( init, binary_op2(*first1, *first2) ), ...

Unlike the C++ Standard Template Library function std::inner_product, this version offers no guarantee on order of execution.

#include <thrust/inner_product.h>
...
float vec1[3] = {1.0f, 2.0f, 5.0f};
float vec2[3] = {4.0f, 1.0f, 5.0f};

float init = 0.0f;
::cuda::std::plus<float>       binary_op1;
::cuda::std::multiplies<float> binary_op2;

float result = thrust::inner_product(vec1, vec1 + 3, vec2, init, binary_op1, binary_op2);

// result == 31.0f

See also

https://en.cppreference.com/w/cpp/algorithm/inner_product

Parameters:

• first1 – The beginning of the first sequence.

• last1 – The end of the first sequence.

• first2 – The beginning of the second sequence.

• init – Initial value of the result.

• binary_op1 – Generalized addition operation.

• binary_op2 – Generalized multiplication operation.

Template Parameters:

• InputIterator1 – is a model of Input Iterator, and InputIterator1's value_type is convertible to BinaryFunction2's first argument type.

• InputIterator2 – is a model of Input Iterator. and InputIterator2's value_type is convertible to BinaryFunction2's second argument type.

• OutputType – is a model of Assignable, and OutputType is convertible to BinaryFunction1's first argument type.

• BinaryFunction1 – The function’s return type must be convertible to OutputType.

• BinaryFunction2 – The function’s return type must be convertible to BinaryFunction1's second argument type.

Returns:

The inner product of sequences [first1, last1) and [first2, last2).