accuracy

auto xt = tensor!([0, 1])([0.1, 0.9, 0.8, 0.2]);
auto y0 = tensor!([0, 1])([1.0, 0.0, 0.0, 1.0]); // true: 0
auto y1 = tensor!([0, 1])([1.0, 0.0, 1.0, 1.0]); // true: 1
auto y2 = tensor!([0, 1])([1.0, 1.0, 1.0, 1.0]); // true: 2
auto y3 = tensor!([0, 1])([1.0, 1.0, 1.0, 0.0]); // true: 3
auto y4 = tensor!([0, 1])([0.0, 1.0, 1.0, 0.0]); // true: 4

assert(accuracy(xt, y0) == 0.0f);
assert(accuracy(xt, y1) == 0.25f);
assert(accuracy(xt, y2) == 0.5f);
assert(accuracy(xt, y3) == 0.75f);
assert(accuracy(xt, y4) == 1.0f);