update.model {base} | R Documentation |
Model Updating
Description
update.model
is used to update model formulae.
This typically involves adding or dropping terms,
but updates can be more general.
The function works by first identifying the left-hand side
and right-hand side of the old
formula.
It then examines the new
formula and substitutes
the lhs of the old
formula for any occurence
of ".
" on the left of new
, and substitutes
the rhs of the old
formula for any occurence
of ".
" on the right of new
.
The updated formula is returned.
Usage
update.model(old, new)
Arguments
old |
a model formula to be updated. |
new |
a formula giving a template which specifies how to update. |
See Also
terms
, model.matrix
.