% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/conf.int.R
\name{conf.int}
\alias{conf.int}
\title{Demonstration of the concept of confidence intervals}
\usage{
conf.int(level = 0.95, size = 50, cl = c("red", "gray"), ...)
}
\arguments{
\item{level}{the confidence level \eqn{(1 - \alpha)}, e.g. 0.95}

\item{size}{the sample size for drawing samples from N(0, 1)}

\item{cl}{two different colors to annotate whether the confidence intervals
cover the true mean (\code{cl[1]}: no; \code{cl[2]}: yes)}

\item{\dots}{other arguments passed to \code{\link{plot.default}}}
}
\value{
A list containing \item{level }{confidence level} \item{size }{sample
  size} \item{CI}{a matrix of confidence intervals for each sample}
  \item{CR}{coverage rate}
}
\description{
This function gives a demonstration of the concept of confidence intervals in
mathematical statistics.
}
\details{
Keep on drawing samples from the Normal distribution N(0, 1), computing the
intervals based on a given confidence level and plotting them as segments in
a graph. In the end, we may check the coverage rate against the given
confidence level.

Intervals that cover the true parameter are denoted in color \code{cl[2]},
otherwise in color \code{cl[1]}. Each time we draw a sample, we can compute
the corresponding confidence interval. As the process of drawing samples goes
on, there will be a legend indicating the numbers of the two kinds of
intervals respectively and the coverage rate is also denoted in the top-left
of the plot.

The argument \code{nmax} in \code{\link{ani.options}} controls the maximum
times of drawing samples.
}
\references{
George Casella and Roger L. Berger. \emph{Statistical Inference}.
  Duxbury Press, 2th edition, 2001.
}
\author{
Yihui Xie
}
