MATLAB Function Reference |

**Syntax**

**Description**

```
K = kron(X,Y)
```

returns the Kronecker tensor product of `X`

and `Y`

. The result is a large array formed by taking all possible products between the elements of `X`

and those of `Y`

. If `X`

is `m`

-by-`n`

and `Y`

is `p`

-by-`q`

, then `kron(X,Y)`

is `m*p`

-by-`n*q`

.

**Examples**

If `X`

is 2-by-3, then `kron(X,Y)`

is

The matrix representation of the discrete Laplacian operator on a two-dimensional, `n`

-by-`n`

grid is a `n^2`

-by-`n^2`

sparse matrix. There are at most five nonzero elements in each row or column. The matrix can be generated as the Kronecker product of one-dimensional difference operators with these statements:

Plotting this with the `spy`

function for `n = 5`

yields:

keyboard | lasterr |