A method for the generic function
selfStart for formula objects.
USAGE:
selfStart(model, initial, parameters, template)
REQUIRED ARGUMENTS:
model
a function object defining a nonlinear model.
initial
a function object, taking three arguments:
mCall,
data, and
LHS, representing, respectively, a matched call to the function
model, a data frame in which to interpret the variables in
mCall,
and the expression from the left hand side of the model formula in
the call to
nls. This function should return initial values for the
parameters in
model.
OPTIONAL ARGUMENTS:
parameters, template
these arguments are included for
consistency with the call to the generic function, but are not used
in the
default method. See the documentation on
selfStart.formula.
VALUE:
a function object of class
selfStart, corresponding to a
self-starting nonlinear model function. An
initial attribute
(defined by the
initial argument) is added to the function to
calculate starting estimates for the parameters in the model
automatically.
SEE ALSO:
EXAMPLES:
# `first.order.log.model' is a function object defining a first order
# compartment model
# `first.order.log.initial' is a function object which calculates initial
# values for the parameters in `first.order.log.model'
# self-starting first order compartment model
SSfol <- selfStart(first.order.log.model, first.order.log.initial)