Calculate the degrees of freedom for a given model from a cSEMResults object.

```
calculateDf(
.object = NULL,
.null_model = FALSE,
...
)
```

## Arguments

- .object
An R object of class cSEMResults resulting from a call to `csem()`

.

- .null_model
Logical. Should the degrees of freedom for the null model
be computed? Defaults to `FALSE`

.

- ...
Ignored.

## Value

A single numeric value.

## Details

Although, composite-based estimators always retrieve parameters of the
postulated models via the estimation of a composite model,
the computation of the degrees of freedom depends on the postulated model.

See: cSEM website
for details on how the degrees of freedom are calculated.

To compute the degrees of freedom of the null model use `.null_model = TRUE`

.
The degrees of freedom of the null model are identical to the number of
non-redundant off-diagonal elements of the empirical indicator correlation matrix.
This implicitly assumes a null model with model-implied indicator correlation
matrix equal to the identity matrix.