1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
|
\name{parm}
\alias{parm}
\title{ Model Parameters }
\description{
Directly specify estimated model parameters and their covariance matrix.
}
\usage{
parm(coef, vcov, df = 0)
}
\arguments{
\item{coef}{ estimated coefficients.}
\item{vcov}{ estimated covariance matrix of the coefficients.}
\item{df}{ an optional specification of the degrees of freedom to be used in
subsequent computations. }
}
\details{
When only estimated model parameters and the corresponding
covariance matrix is available for simultaneous inference
using \code{\link{glht}} (for example, when only the results
but not the original data are available or, even worse, when the model
has been fitted outside R), function \code{parm} sets up an
object \code{\link{glht}} is able to compute on (mainly
by offering \code{coef} and \code{vcov} methods).
Note that the linear function in \code{\link{glht}} can't
be specified via \code{\link{mcp}} since the model terms
are missing.
}
\value{
An object of class \code{parm} with elements
\item{coef}{model parameters}
\item{vcov}{covariance matrix of model parameters}
\item{df}{degrees of freedom}
}
\examples{
## example from
## Bretz, Hothorn, and Westfall (2002).
## On multiple comparisons in R. R News, 2(3):14-17.
beta <- c(V1 = 14.8, V2 = 12.6667, V3 = 7.3333, V4 = 13.1333)
Sigma <- 6.7099 * (diag(1 / c(20, 3, 3, 15)))
confint(glht(model = parm(beta, Sigma, 37),
linfct = c("V2 - V1 >= 0",
"V3 - V1 >= 0",
"V4 - V1 >= 0")),
level = 0.9)
}
\keyword{misc}
|
