Plots of the Output of a Fractional Weighted Bootstrap

plot.fwb() takes an fwb object and produces plots for the bootstrap replicates of the statistic of interest.

Usage

# S3 method for fwb
plot(
  x,
  index = 1,
  qdist = "norm",
  nclass = NULL,
  df,
  type = c("hist", "qq"),
  ...
)

Arguments

x: an fwb object; the output of a call to fwb().
index: the index of the position of the quantity of interest in x$t0 if more than one was specified in fwb(). Only one value is allowed at a time. By default the first statistic is used.
qdist: character; when a Q-Q plot is requested (as it is by default; see type argument below), the distribution against which the Q-Q plot should be drawn. Allowable options include "norm" (normal distribution - the default) and "chisq" (chi-squared distribution).
nclass: when a histogram is requested (as it is by default; see type argument below), the number of classes to be used. The default is the integer between 10 and 100 closest to ceiling(length(R)/25) where R is the number of bootstrap replicates.
df: if qdist is "chisq", the degrees of freedom for the chi-squared distribution to be used. If not supplied, the degrees of freedom will be estimated using maximum likelihood.
type: the type of plot to display. Allowable options include "hist" for a histogram of the bootstrap estimates and "qq" for a Q-Q plot of the estimates against the distribution supplied to qdist.
...: ignored.

Value

x is returned invisibly.

Details

This function can produces two side-by-side plots: a histogram of the bootstrap replicates and a Q-Q plot of the bootstrap replicates against theoretical quantiles of a supplied distribution (normal or chi-squared). For the histogram, a vertical dotted line indicates the position of the estimate computed in the original sample. For the Q-Q plot, the expected line is plotted.

Examples

# See examples at help("fwb")