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.
NAs. 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
NAs 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)