vcov.DRMod: Calculate the (asymptotic) variance covariance matrix of a DRMod object
Description
Calculate (asymptotic) confidence intervals for parameters in a DRMod object,
based on standard asymptotic theory for nonlinear models, see Seber and Wild (2003).
Usage
## S3 method for class 'DRMod':
vcov(object, data = getData(object), uGrad = NULL, ...)
Arguments
object
A DRMod object.
data
Data frame containing the variables on which the DRMod object was
fitted (this needs to be handed over if DRMod object does not
contain the data on which is was fitted).
uGrad
Function to return the gradient of a user defined model, see
Examples of the fitDRModel function.
...
Additional arguments
Value
The covariance matrix
References
Seber, G.A.F and Wild, C.F. (2003). Nonlinear Regression, Wiley & Sons