Data
is partitioned according to the levels of the grouping
factor defined in
model
and individual
nls
fits are
obtained for each
data
partition, using the model defined in
model
.
nlsList(model, data, start, control, level, na.action, pool)
selfStart
function. The
method function
nlsList.selfStart
is documented separately.
model
.
model
. It is passed as the
start
argument to each
nls
call and is required when
the nonlinear function in
model
does not inherit from class
selfStart
.
control
argument to
nls
. Defaults to an empty list.
NA
s. The default action (
na.fail
) causes
nlsList
to print an error message and terminate if there are any
incomplete observations.
pool
in
calculations of standard deviations or standard errors for summaries.
nls
objects with as many components as the number of
groups defined by the grouping factor. Generic functions such as
coef
,
fixed.effects
,
lme
,
pairs
,
plot
,
predict
,
random.effects
,
summary
,
and
update
have methods that can be applied to an
nlsList
object.
If one of the individual
nls
fits fails, an ERROR message will appear.
The remainder models will still be fitted assigning
NA
s to the coefficients
of the model for the group whose fit failed.
The computational method used to accomplish the recursive fitting of
the individual models to the groups regardless of one of them failing,
will sometimes result on multiple errors
if a mistake is made on model specification, for example.
A pervasive error of this type will
appear as many times as there are groups in the data frame.
fm1 <- nlsList(weight ~ SSlogis(Time, Asym, xmid, scal) | Plot, Soybean)