Tensor<double,2,3> mat = {{1,2,3},
                          {4,5,6}};

Tensor<double,2,2,3> array_3d = {{{1,2,3},
                                  {4,5,6}},
                                  {{8,9,10},
                                  {11,12,13}}};

Tensor<int,4,4> a(5);
Tensor<float,2,2> b(0.f);

double c_array[4] = {1,2,3,4};
Tensor<double,4> a(c_array); // construct a vector from c_array
Tensor<double,2,2> a(c_array); // construct a matrix from c_array

std::array<double,4> std_array = {1,2,3,4};
Tensor<double,2,2> a(std_array); // construct a matrix from std::array
std::vector<double> std_vec = {1,2,3,4};
Tensor<double,2,2> a(std_vec); // construct a matrix from std::vector

Tensor<float,3,4,5> a;
a.zeros(); // fill all the elements with zero
a.ones(); // fill all the elements with one
a.fill(2.5); // fill all the elements with 2.5
a.random(); // fill all the elements with random numbers
a.iota(3); // fill all the elements with sequentially ascending number starting from 3
a.arange(3); // fill all the elements with sequentially ascending number starting from 3. Same as above