# tensorplay.functional.kron

Source: https://www.tensorplay.cn/docs/generated/tensorplay.functional.kron.html

```python
tensorplay.functional.kron(input, other, *, out=None) → Tensor
```

Computes the Kronecker product, denoted by $\otimes$, of input and other.

If input is a $(a_0 \times a_1 \times \dots \times a_n)$ tensor and other is a
$(b_0 \times b_1 \times \dots \times b_n)$ tensor, the result will be a
$(a_0*b_0 \times a_1*b_1 \times \dots \times a_n*b_n)$ tensor with the following entries:

$$(\text{input} \otimes \text{other})_{k_0, k_1, \dots, k_n} =
    \text{input}_{i_0, i_1, \dots, i_n} * \text{other}_{j_0, j_1, \dots, j_n},$$

where $k_t = i_t * b_t + j_t$ for $0 \leq t \leq n$.
If one tensor has fewer dimensions than the other it is unsqueezed until it has the same number of dimensions.

Supports real-valued and complex-valued inputs.

> **Note**
>
> This function generalizes the typical definition of the Kronecker product for two matrices to two tensors, as described above. When input is a $(m \times n)$ matrix and other is a $(p \times q)$ matrix, the result will be a $(p*m \times q*n)$ block matrix: @@TPBLOCK_2@@ where input is $\mathbf{A}$ and other is $\mathbf{B}$.

Parameters:

- input ([Tensor](/docs/generated/tensorplay.Tensor.html#tensorplay.Tensor))

- other ([Tensor](/docs/generated/tensorplay.Tensor.html#tensorplay.Tensor))

Keyword Arguments:

out ([Tensor](/docs/generated/tensorplay.Tensor.html#tensorplay.Tensor), optional) – The output tensor. Ignored if None. Default: None

Examples:

```
>>> mat1 = tensorplay.eye(2)
>>> mat2 = tensorplay.ones(2, 2)
>>> tensorplay.kron(mat1, mat2)
tensor([[1., 1., 0., 0.],
        [1., 1., 0., 0.],
        [0., 0., 1., 1.],
        [0., 0., 1., 1.]])

>>> mat1 = tensorplay.eye(2)
>>> mat2 = tensorplay.arange(1, 5).reshape(2, 2)
>>> tensorplay.kron(mat1, mat2)
tensor([[1., 2., 0., 0.],
        [3., 4., 0., 0.],
        [0., 0., 1., 2.],
        [0., 0., 3., 4.]])
```