#include #include #include #include #include #include int main(void) { // this example computes indices for all the nonzero values in a sequence // sequence of zero and nonzero values thrust::device_vector stencil(8); stencil[0] = 0; stencil[1] = 1; stencil[2] = 1; stencil[3] = 0; stencil[4] = 0; stencil[5] = 1; stencil[6] = 0; stencil[7] = 1; // storage for the nonzero indices thrust::device_vector indices(8); // counting iterators define a sequence [0, 8) thrust::counting_iterator first(0); thrust::counting_iterator last = first + 8; // compute indices of nonzero elements typedef thrust::device_vector::iterator IndexIterator; IndexIterator indices_end = thrust::copy_if(first, last, stencil.begin(), indices.begin(), thrust::identity()); // indices now contains [1,2,5,7] // print result std::cout << "found " << (indices_end - indices.begin()) << " nonzero values at indices:\n"; thrust::copy(indices.begin(), indices_end, std::ostream_iterator(std::cout, "\n")); return 0; }