% File src/library/datasets/man/attenu.Rd
% Part of the R package, http://www.R-project.org
% Copyright 1995-2007 R Core Development Team
% Distributed under GPL 2 or later

\name{attenu}
\docType{data}
\alias{attenu}
\title{The Joyner--Boore Attenuation Data}
\description{
  This data gives peak accelerations measured at various observation
  stations for 23 earthquakes in California.  The data have been used
  by various workers to estimate the attenuating affect of distance
  on ground acceleration.
}
\usage{attenu}
\format{
  A data frame with 182 observations on 5 variables.
  \tabular{rlll}{
    [,1] \tab event   \tab numeric \tab Event Number\cr
    [,2] \tab mag     \tab numeric \tab Moment Magnitude\cr
    [,3] \tab station \tab factor  \tab Station Number\cr
    [,4] \tab dist    \tab numeric \tab Station-hypocenter distance (km)\cr
    [,5] \tab accel   \tab numeric \tab Peak acceleration (g)}
}
\source{
  Joyner, W.B., D.M. Boore and R.D. Porcella (1981).  Peak horizontal
  acceleration and velocity from strong-motion records including
  records from the 1979 Imperial Valley, California earthquake.  USGS
  Open File report 81-365. Menlo Park, Ca.
}
\references{
  Boore, D. M. and Joyner, W.B.(1982)
  The empirical prediction of ground motion,
  \emph{Bull. Seism. Soc. Am.}, \bold{72}, S269--S268.

  Bolt, B. A. and Abrahamson, N. A. (1982)
  New attenuation relations for peak and expected accelerations of
  strong ground motion,
  \emph{Bull. Seism. Soc. Am.}, \bold{72}, 2307--2321.

  Bolt B. A. and Abrahamson, N. A. (1983)
  Reply to W. B. Joyner & D. M. Boore's \dQuote{Comments on: New
    attenuation relations for peak and expected accelerations for peak
    and expected accelerations of strong ground motion},
  \emph{Bull. Seism. Soc. Am.}, \bold{73}, 1481--1483. 

  Brillinger, D. R. and Preisler, H. K. (1984)
  An exploratory analysis of the Joyner-Boore attenuation data,
  \emph{Bull. Seism. Soc. Am.}, \bold{74}, 1441--1449.

  Brillinger, D. R. and Preisler, H. K. (1984)
  \emph{Further analysis of the Joyner-Boore attenuation data}.
  Manuscript.
}
\examples{
require(graphics)
## check the data class of the variables
sapply(attenu, data.class)
summary(attenu)
pairs(attenu, main = "attenu data")
coplot(accel ~ dist | as.factor(event), data = attenu, show.given = FALSE)
coplot(log(accel) ~ log(dist) | as.factor(event),
       data = attenu, panel = panel.smooth, show.given = FALSE)
}
\keyword{datasets}
