conf:Visualization and Analysis of Statistical Measures of Confidence
Enables: (1) plotting two-dimensional confidence regions, (2) coverage analysis of confidence region simulations, (3)
calculating confidence intervals and the associated actual
coverage for binomial proportions, (4) calculating the support
values and the probability mass function of the Kaplan-Meier
product-limit estimator, and (5) plotting the actual coverage
function associated with a confidence interval for the survivor
function from a randomly right-censored data set. Each is given
in greater detail next. (1) Plots the two-dimensional
confidence region for probability distribution parameters
(supported distribution suffixes: cauchy, gamma, invgauss,
logis, llogis, lnorm, norm, unif, weibull) corresponding to a
user-given complete or right-censored dataset and level of
significance. The crplot() algorithm plots more points in
areas of greater curvature to ensure a smooth appearance
throughout the confidence region boundary. An alternative
heuristic plots a specified number of points at roughly uniform
intervals along its boundary. Both heuristics build upon the
radial profile log-likelihood ratio technique for plotting
confidence regions given by Jaeger (2016)
<doi:10.1080/00031305.2016.1182946>, and are detailed in a
publication by Weld et al. (2019)
<doi:10.1080/00031305.2018.1564696>. (2) Performs confidence
region coverage simulations for a random sample drawn from a
user- specified parametric population distribution, or for a
user-specified dataset and point of interest with coversim().
(3) Calculates confidence interval bounds for a binomial
proportion with binomTest(), calculates the actual coverage
with binomTestCoverage(), and plots the actual coverage with
binomTestCoveragePlot(). Calculates confidence interval bounds
for the binomial proportion using an ensemble of constituent
confidence intervals with binomTestEnsemble(). Calculates
confidence interval bounds for the binomial proportion using a
complete enumeration of all possible transitions from one
actual coverage acceptance curve to another which minimizes the
root mean square error for n <= 15 and follows the transitions
for well-known confidence intervals for n > 15 using
binomTestMSE(). (4) The km.support() function calculates the
support values of the Kaplan-Meier product-limit estimator for
a given sample size n using an induction algorithm described in
Qin et al. (2023) <doi:10.1080/00031305.2022.2070279>. The
km.outcomes() function generates a matrix containing all
possible outcomes (all possible sequences of failure times and
right-censoring times) of the value of the Kaplan-Meier
product-limit estimator for a particular sample size n. The
km.pmf() function generates the probability mass function for
the support values of the Kaplan-Meier product-limit estimator
for a particular sample size n, probability of observing a
failure h at the time of interest expressed as the cumulative
probability percentile associated with X = min(T, C), where T
is the failure time and C is the censoring time under a
random-censoring scheme. The km.surv() function generates
multiple probability mass functions of the Kaplan-Meier
product-limit estimator for the same arguments as those given
for km.pmf(). (5) The km.coverage() function plots the actual
coverage function associated with a confidence interval for the
survivor function from a randomly right-censored data set for
one or more of the following confidence intervals: Greenwood,
log-minus-log, Peto, arcsine, and exponential Greenwood. The
actual coverage function is plotted for a small number of items
on test, stated coverage, failure rate, and censoring rate. The
km.coverage() function can print an optional table containing
all possible failure/censoring orderings, along with their
contribution to the actual coverage function.