This function evaluates initial parameter estimates for a nonlinear
regression model. If
data is a parameterized data frame or
pframe
object, its
parameters attribute is returned.
Otherwise the object is examined to see if it contains a call to a
selfStart
object whose
initial attribute can be
evaluated.
USAGE:
getInitial(object, data, ...)
REQUIRED ARGUMENTS:
object
a formula or a
selfStart model that defines a
nonlinear regression model
data
a data frame in which the expressions in the formula or
arguments to the
selfStart model can be evaluated
...
optional additional arguments
VALUE:
A named numeric vector or list of starting estimates for the
parameters. The construction of many
selfStart models is such
that these "starting" estimates are, in fact, the converged parameter
estimates.
SEE ALSO:
,
,
,
,
EXAMPLES:
PurTrt <- Puromycin[ Puromycin$state == "treated", ]
getInitial( vel ~ SSmicmen( conc, Vm, K ), PurTrt )