getInitial {stats} | R Documentation |
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.
getInitial(object, data, ...)
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 |
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.
Jose Pinheiro and Douglas Bates
nls
,
selfStart
,
selfStart.default
, selfStart.formula
PurTrt <- Puromycin[ Puromycin$state == "treated", ] getInitial( rate ~ SSmicmen( conc, Vm, K ), PurTrt )