R likes it when these things have documentation.

```
update(object, ...)
# S3 method for dpm
update(object, formula., ..., evaluate = TRUE)
# S4 method for dpm
update(object, formula., ..., evaluate = TRUE)
# S4 method for dpm
show(object)
coef(object, ...)
# S3 method for dpm
coef(object)
# S4 method for dpm
coef(object)
# S4 method for dpm
formula(x)
```

## Arguments

- object
A `dpm`

object

- ...
Other arguments to update.

- formula.
An updated formula (optional)

- evaluate
If updating, should the updated model be updated or just
return the call? Default is TRUE, re-run the model.

- x
A `dpm`

object

## Value

`update.dpm()`

: Returns an updated `dpm`

object.

`coef.dpm()`

: Returns a numeric vector of coefficients. If the model
was fit with `x.free = TRUE`

and/or `y.free = TRUE`

, the coefficient
names will be formatted with an underscore and the wave corresponding to
which time period the coefficient is estimated for.

`formula.dpm()`

: Returns the formula used to fit the model as a
`Formula`

object. The formula is the input to `dpm()`

, not the `lavaan`

syntax.

`show.dpm()`

: Returns an invisible "NULL" while printing model info
to console.

## Examples

```
data("WageData", package = "panelr")
wages <- panel_data(WageData, id = id, wave = t)
fit <- dpm(wks ~ pre(lag(union)) + lag(lwage), data = wages)
# Re-run model without `lag(lwage)` term
update(fit, . ~ . - lag(lwage))
#> Error in eval(call, parent.frame()): object 'wages' not found
```