

_B_o_x _P_l_o_t_s

     boxplot(x, ..., range = 1.5, width = NULL, varwidth = FALSE,
             notch = FALSE, names.x, data = sys.frame(sys.parent()),
             plot = TRUE, border = par("fg"), col = NULL, log = "",
             pars = NULL)

_A_r_g_u_m_e_n_t_s:

     ...: the data from which the boxplots are to be pro-
          duced.  The data can be specified as separate vec-
          tors, each corresponding to a component boxplot,
          or as a single list containing such vectors.
          Alternatively a symbolic specification of the form
          `x ~ g' can be given, indicating the the observa-
          tions in the vector `x' are to be grouped accord-
          ing to the levels of the factor `g'.  In this case
          the argument `data' can be used to provide values
          for the variables in the specification.  `NA's are
          allowed in the data.

   range: this determines how far the plot whiskers extend
          out from the box.  If `range' is positive, the
          whiskers extend to the most extreme data point
          which is no more than `range' times the interquar-
          tile range from the box.  A value of zero causes
          the whiskers to extend to the data extremes.

   width: a vector giving the relative widths of the boxes
          making up the plot.

varwidth: if `varwidth' is `TRUE', the boxes are drawn with
          widths proportional to the square-roots of the
          number of observations in the groups.

   notch: if `notch' is `TRUE', a notch is drawn in each
          side of the boxes.  If the notches of two plots do
          not overlap then the medians are significantly
          different at the 5 percent level.

 names.x: group labels which while be printed under each
          boxplot.

    data: `data.frame', `list', or `environment' in which
          variable names are evaluated when `x' is a for-
          mula.

    plot: if `TRUE' (the default) then a boxplot is pro-
          duced.  If not, the summaries which the boxplots
          are based on are returned.

  border: an optional vector of colors for the outlines of
          the boxplots.  The values in `border' are recycled
          if the length of `border' is less than the number
          of plots.

     col: if `col' is non-null it is assumed to contain
          colors to be used to col the bodies of the box
          plots.

     log: character indicating if x- or y- or both coordi-
          nates should be plotted in log scale.

pars, ...: graphical parameters can also be passed as argu-
          ments to `boxplot'.

_V_a_l_u_e:

     This function is usually invoked for its side effect
     which is to produce box-and-whisker plots of the given
     values.  However, it also returns a list with one com-
     ponent corresponding to each plot.  The components are
     themselves lists with named components as follows:

   stats: a vector containing the extreme of the lower
          whisker, the lower hinge, the median, the upper
          hinge and the extreme of the upper whisker.

       n: the number of observations in the sample.

    conf: the lower and upper extremes of the notch.

     out: the values of any data points which lie beyond the
          extremes of the whiskers.

_S_e_e _A_l_s_o:

     `boxplot.stats' which does the computation, `bxp' for
     the plotting, and `stripplot' for an alternative (with
     small data sets).

     `plot.default' for some high-level plotting parameters.

_E_x_a_m_p_l_e_s:

     data(insects)
     boxplot(count ~ spray, data = insects, col = "lightgray")

     data(bees)
     boxplot(decrease ~ treatment, data = bees, log = "y", col="bisque")

