assumed probability distribution for plots. This must be one of
"weibull",
"extreme",
"lognormal",
"normal",
"loglogistic",
"logistic",
"logexponential",
"exponential",
"lograyleigh",
"rayleigh".
Default is
"weibull". Additionally,
"loggaussian" and
"gaussian" may
be specified as alternates to
"lognormal" and
"normal", respectively.
data
a data frame in which to interpret the variables named in
x,
weights, and
subset.
weights
vector of observation weights; if supplied, the fitting algorithms fit to
minimize the sum of the weights multiplied into the likelihood contribution
for each observation. In this way, and in the computation of degrees of freedom,
the weights behave like frequencies. The length of weights must be the same as
the number of observations. The weights must be nonnegative and it is strongly
recommended that they be strictly positive, since zero weights are ambiguous,
compared to use of the subset argument.
subset
expression indicating a subset of the rows of
data to use in the plot.
Default uses all rows of
data depending on
na.action.
na.action
a missing-data filter function, applied to the data frame, after any subset
argument has been used. Default is
na.exclude.
method
character string specifying method for computing the plotted points.
The options are
"km" and
"nelson". The default is
"km" which uses
Kaplan-Meier quantiles for plotting. In this case the cumulative probabilities
are plotted at the unique quantiles. The
"nelson" method plots all
observations whether there are ties or not at the probability points
((1:n) - 1/2)/n after eliminating censored observations.
mle
logical value indicating whether or not to plot a line representing the
maximum likelihood estimates of the parameters of the distribution.
Default is
F.
mle.interval
logical value indicating whether or not to plot confidence intervals of the
mle. Default is
F.
coverage
numeric value specifying the confidence level for the confidence bounds of the
mle.
add.censored
logical value indicating whether or not to plot the censored observations.
Right censored observations are plotted with a
+ symbol, left censored
observations are plotted with a
- symbol and interval observations are
plotted with a diamond symbol.
xlim
numeric vector of length two specifying the x-axis limits on the scale of
x.
ylim
numeric vector of length two specifying the y-axis limits on the probability
scale.
SIDE EFFECTS::
Produces a probability plot of
x on the current graphics device.
SEE ALSO:
EXAMPLES:
probplot(censor(days, event), data = capacitor2, weights = weights)