thrust::adjacent_difference

Defined in thrust/adjacent_difference.h

template<typename DerivedPolicy, typename InputIterator, typename OutputIterator> OutputIterator thrust::adjacent_difference(const thrust::detail::execution_policy_base<DerivedPolicy> &exec, InputIterator first, InputIterator last, OutputIterator result)

adjacent_difference calculates the differences of adjacent elements in the range [first, last). That is, *first is assigned to *result, and, for each iterator i in the range [first + 1, last), the difference of *i and *(i - 1) is assigned to *(result + (i - first)).

This version of adjacent_difference uses operator- to calculate differences.

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

The following code snippet demonstrates how to use adjacent_difference to compute the difference between adjacent elements of a range using the thrust::device execution policy:

Remark

Note that result is permitted to be the same iterator as first. This is useful for computing differences “in place”.

#include <thrust/adjacent_difference.h>
#include <thrust/device_vector.h>
#include <thrust/execution_policy.h>
...
int h_data[8] = {1, 2, 1, 2, 1, 2, 1, 2};
thrust::device_vector<int> d_data(h_data, h_data + 8);
thrust::device_vector<int> d_result(8);

thrust::adjacent_difference(thrust::device, d_data.begin(), d_data.end(), d_result.begin());

// d_result is now [1, 1, -1, 1, -1, 1, -1, 1]