Functions for visualizing the output from bmonomvn,
  particularly the posterior standard deviation estimates of the mean
  vector and covariance matrix, and samples from the solution to a
  Quadratic Program
# S3 method for monomvn
plot(x, which=c("mu", "S", "Snz", "Sinz", "QP"),
     xaxis=c("numna", "index"), main=NULL, uselog=FALSE, ...)a "monomvn"-class object that must be named x
    for generic plotting
determines the parameter whose standard deviation
    to be visualized: the mean vector ("mu" for sqrt($mu.var));
    the covariance matrix ("S" for sqrt($S.var)),
    or "S{i}nz" for sqrt($S{i}.nz), which both result in
    an image plot; or the distribution of solutions
    $W to a Quadratic Program that may be obtained by
    supplying QP = TRUE as input to bmonomvn
indicates how x-axis (or x- and y-axis in the case
    of which = "S" || "S{i}nz") should be displayed.  The default option
    "numna" shows the (ordered) number of missing entries
    (NAs) in the corresponding column, whereas "index"
    simply uses the column index; see details below
optional text to be added to the main title of the plots;
    the default of NULL causes the automatic generation of a
    title
a logical which, when TRUE, causes the log
    of the standard deviation to be plotted instead
passed to plot.default
The only output of this function is beautiful plots
Currently, this function only provides a visualization of the
  posterior standard deviation estimates of the parameters, and
  the distributions of samples from the posterior of the solution
  to a specified Quadratic Program.  Therefore
  it only works on the output from bmonomvn
All types of visualization (specified by which) are presented
  in the order of the number of missing entries in the columns of the
  data passed as input to  bmonomvn.
  In the case of which = "mu"
  this means that y-values are presented in the order x$o, where
  the x-axis is either 1:length(x$o) in the case of
  xaxis = "index", or x$na[x$o] in the case of xaxis
    = "numna".  When which = "S" is given the resulting
  image plot is likewise ordered by x$o where the
  x- and y-axis are as above, except that in the case
  where xaxis = "numna" the repeated counts of NAs are
  are adjusted by small increments so that x and y arguments to
  image are distinct.  Since a boxplot is
  used when which = "QP" it may be that xaxis = "index"
  is preferred