如何计算特征::张量中的非零数<T,2>

Question

If I use the sum of bool tensor, the reuslt is 1 forever

Eigen::Tensor<int,2> my_rankx (3,3);
my_rankx.setValues(
{
    {1, 2, 3},
    {0, 0, 0},
    {11, 12, 0}
});

auto number_matrix = (my_rankx.constant(static_cast<int>(0))==my_rankx);
cout<<number_matrix.sum()<<endl; // result of cout is 1

Answer 1

(my_rankx.constant(0) == my_rankx) is a tensor of bool s, and adding bool s together results in either false or true , which are converted to 0 and 1 respectively. (Incidentally, the static_cast<int>(0) in the question is redundant because 0 is of type int .)

You can use std::count along with data() instead:

std::cout << std::count(my_rankx.data(), my_rankx.data() + my_rankx.size(), 0)
          << "\n";