\name{coronary}
\docType{data}
\alias{coronary}
\title{Coronary heart disease data set}
\description{

  Probable risk factors for coronary thrombosis, comprising data from 1841 men.

}
\usage{
data(coronary)
}
\format{

  The \code{coronary} data set contains the following 6 variables:
  \itemize{

    \item \code{Smoking} (\emph{smoking}): a two-level factor with levels
      \code{no} and \code{yes}.
    \item \code{M. Work} (\emph{strenuous mental work}): a two-level factor
      with levels \code{no} and \code{yes}.
    \item \code{P. Work} (\emph{strenuous physical work}): a two-level factor
      with levels \code{no} and \code{yes}.
    \item \code{Pressure} (\emph{systolic blood pressure}): a two-level factor
      with levels \code{<140} and \code{>140}.
    \item \code{Proteins} (\emph{ratio of beta and alpha lipoproteins}): a
      two-level factor with levels \code{<3} and \code{>3}.
    \item \code{Family} (\emph{family anamnesis of coronary heart disease}): a
      two-level factor with levels \code{neg} and \code{pos}.

  }

}
\source{

  Edwards DI (2000). \emph{Introduction to Graphical Modelling}. Springer, 2nd
    edition.

  Reinis Z, Pokorny J, Basika V, Tiserova J, Gorican K, Horakova D, Stuchlikova
    E, Havranek T, Hrabovsky F (1981). "Prognostic Significance of the Risk
    Profile in the Prevention of Coronary Heart Disease." \emph{Bratisl Lek
    Listy}, \strong{76}:137--150. Published in Bratislava Medical Journal,
    in Czech.

  Whittaker J (1990). \emph{Graphical Models in Applied Multivariate
    Statistics}. Wiley.

}
\examples{

# This is the undirected graphical model from Whittaker (1990).
data(coronary)
ug = empty.graph(names(coronary))
arcs(ug, check.cycles = FALSE) = matrix(
  c("Family", "M. Work", "M. Work", "Family",
    "M. Work", "P. Work", "P. Work", "M. Work",
    "M. Work", "Proteins", "Proteins", "M. Work",
    "M. Work", "Smoking", "Smoking", "M. Work",
    "P. Work", "Smoking", "Smoking", "P. Work",
    "P. Work", "Proteins", "Proteins", "P. Work",
    "Smoking", "Proteins", "Proteins", "Smoking",
    "Smoking", "Pressure", "Pressure", "Smoking",
    "Pressure", "Proteins", "Proteins", "Pressure"),
  ncol = 2, byrow = TRUE,
  dimnames = list(c(), c("from", "to")))
\dontrun{graphviz.plot(ug, shape = "ellipse")}
}
\keyword{datasets}
