\Header{confint}{Confidence Intervals for Model Parameters}
\keyword{models}{confint}
\begin{Description}\relax
Computes confidence intervals for one or more parameters in a fitted
model.  Base has a method for objects inheriting from class
\code{"lm"}.
\end{Description}
\begin{Usage}
\begin{verbatim}
confint(object, parm, level = 0.95, ...)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{object}] a fitted model object.

\item[\code{parm}] a specification of which parameters are to be given confidence
intervals, either a vector of numbers or a vector of names. If
missing, all parameters are considered.

\item[\code{level}] the confidence level required.

\item[\code{...}] additional argument(s) for methods

\end{ldescription}
\end{Arguments}
\begin{Details}\relax
\code{confint} is a generic function with no default method.
For objects of class \code{"lm"} the direct formulae based on t values
are used.

Package \pkg{MASS} contains methods for \code{"glm"} and \code{"nls"}
objects.
\end{Details}
\begin{Value}
A matrix (or vector) with columns giving lower and upper confidence
limits for each parameter. These will be labelled as (1-level)/2 and
1 - (1-level)/2 in \% (by default 2.5\% and 97.5\%).
\end{Value}
\begin{SeeAlso}\relax
\code{\Link{confint.nls}}
\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
data(mtcars)
fit <- lm(100/mpg ~ disp + hp + wt + am, data=mtcars)
confint(fit)
confint(fit, "wt")
\end{ExampleCode}
\end{Examples}

