| bread.drc {drc} | R Documentation |
Bread and meat for the sandwich estimator of the variance-covariance.
bread.drc(x, ...) estfun.drc(x, ...)
x |
object of class drc |
... |
additional arguments. At the moment none are supported. |
More explanations are found in Zeileis (2006).
The unscaled hessian is returned by bread.drc, whereas estfun.drc
returns the estimating function evaluated at the data and the parameter estimates.
Christian Ritz
Zeileis, A. (2006) Object-oriented Computation of Sandwich Estimators, J. Statist. Software, 16, Issue 9.
For other applications see sandwich.
## The lines below requires that the packages ## 'lmtest' and 'sandwich' are installed #library(lmtest) #library(sandwich) #ryegrass.m1<-drm(rootl~conc, data=ryegrass, fct=LL.4()) #coeftest(ryegrass.m1) #coeftest(ryegrass.m1, vcov=sandwich)