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#include <thrust/device_vector.h>
#include <thrust/functional.h>
#include <thrust/inner_product.h>
#include <cmath>
#include <iostream>
#include "include/host_device.h"
// this example computes the maximum absolute difference
// between the elements of two vectors
template <typename T>
struct abs_diff : public thrust::binary_function<T, T, T>
{
__host__ __device__ T operator()(const T& a, const T& b)
{
return fabsf(b - a);
}
};
int main()
{
thrust::device_vector<float> d_a(4);
thrust::device_vector<float> d_b(4);
// clang-format off
d_a[0] = 1.0; d_b[0] = 2.0;
d_a[1] = 2.0; d_b[1] = 4.0;
d_a[2] = 3.0; d_b[2] = 3.0;
d_a[3] = 4.0; d_b[3] = 0.0;
// clang-format on
// initial value of the reduction
float init = 0;
// binary operations
thrust::maximum<float> binary_op1;
abs_diff<float> binary_op2;
float max_abs_diff = thrust::inner_product(d_a.begin(), d_a.end(), d_b.begin(), init, binary_op1, binary_op2);
std::cout << "maximum absolute difference: " << max_abs_diff << std::endl;
return 0;
}
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