Model Diagnostics page after model fitting page

[NoonanM]

After the model fitting step it would be useful to have a model diagnostic page that use the residuals() and correlogram() functions.

The code would go something like this:

`?residuals
RES <- residuals(DATA,FIT)

plot(RES)

?correlogram
ACF <- correlogram(RES)

plot(ACF)`

[chfleming]

zoom(ACF)