# compute the difference between the full sample covariance and its separable approximation

### Description

compute the difference between the full sample covariance and its separable approximation

### Usage

1 | ```
difference_fullcov(Data)
``` |

### Arguments

`Data` |
a (non-empty) |

### Value

A `d1 x d2 x d1 x d2`

array, where `d1 = nrow(Data)`

and
`d2 = ncol(Data)`

.

### Details

This is an internal function.