options.wblr: Options list for 'wblr' Objects

In WeibullR: Weibull Analysis for Reliability Engineering

Options list for wblr Objects

Description

This function handles the various calculation, printing and plotting options for wblr objects.

Usage

options.wblr(...)

Arguments

...	Options for calculating, printing and plotting wblr objects using the WeibullR package.

Details

Typical usage of wblr objects involves calling a sequence of functions each forming the object, then modifying it in this typical manner:

da <- wblr(c(10,11,27), col="red")
da <- wblr.fit(da, col="darkgreen")
da <- wblr.conf(da), col="blue"
plot(da)

The correct time to specify an option is when it is needed for the first time. For example, when the color setting option col = "red" is passed as an argument of function wblr, it will be used for data points, fitted lines and confidence interval bounds. If supplied to wblr.conf, only the confidence bounds will have the re-specified color, hereby overriding any previously inherited color settings from wblr.fit or wblr.

Do not call options.wblr in between these functions because some options are locked and cannot be altered further in this chain. This is an implication of the way the wblr object is structured.

As a function, options.wblr, borrows its internal structure from the par function of package graphics. It can be used independently of the typical wblr, wblr.fit, wblr.conf sequence, but this is discouraged. However, when used independently the following guidance is provided:

options.wblr()

Returns the currently used options and their values.

options.wblr()$dist options.wblr("dist")

Returns the current value of an option.

options.wblr(ci=0.95) options.wblr(list(ci=0.95,S=5e4))

Sets the specified options.

Currently, there is no way to reset the options to the default values using this function. One might, before changing any options, store the option list in a temporary variable like

wblr.defaults <- options.wblr()

for restoring it later by running options.wblr(wblr.defaults).

The function creates a globally accessible list named options_wblr, holding the options. One should always use the options.wblr function to access the option list, do not access this list directly.

Value

Executing options.wblr without arguments returns a named list containing the currently active global options of the wblr object.
When arguments are supplied, these are returned in a named list.

wblr options

Options specific to initial wblr object creation with data prepared for graphical display

dist

A character string defining the distribution target. When used to establish the basis for contour mapping (without using wblr.conf with method.conf="lrb") only "weibull" (default) and "lognormal" are recognized.
Also used with wblr.fit for specific fitting control.

pp

Plotting position method, it is a character string describing the method of determining vertical plot positions. Implemented methods are "median" (default), "benard","hazen","mean", "kaplan-meier", and "blom".

rank.adj

The method employed for determining rank of failures when suspensions (right censored data) are present in the data set. Implemented methods are "johnson" (default) and "KMestimator".

ties.handler

The method employed for handling duplicate values in the data set.
Implemented methods are "none" (default) "highest", "lowest", "mean", and "sequential".
It is expected that ties handling will be applied to large data sets that will be fitted using the maximum likelihood estimation method, where the effect is only on the graphical presentation. Employing a ties handler on a rank regression model will effectively remove data from the data set, which is likely not intended.
Use of simply ties as an argument to function wblr will silently be accepted as ties.handler.

Options for graphical control over data points see par

• pch Point choice defaults to 1. For more info, see points.

• cex.points Point size defaults to 1.

• lwd.points Line width defaults to 2.

Independent graphical control over interval lines

• interval.col Color defaults to "black".

• interval.lty Line type, defaults to "dashed".

• interval.lwd Line width defaults to 1.

Options specific to wblr.fit

dist

A character string defining the distribution target. Recognized values are "weibull" (default), "lognormal","lnorm","lognormal2p", "weibull2p","lognormal3p", and "weibull3p".

method.fit

A vector of class "character" with fitting options. Recognized values are "rr-xony" (default), "rr","rr-yonx", "mle","mle-rba", and "mle-unbias".

Options specific to wblr.conf

method.conf

A character string describing the techniques used for calculating confidence interval bounds. Implemented methods are "pivotal-rr" (default), "bbb", "fm" "fmbounds", and "lrb". Methods must conform to the method.fit in the wblr.fit call immediately preceding the wblr.conf call. Method "pivotal-rr" requires a rank regression fit method. Methods "fm", "fmbounds", and "lrb" require a mle based fit.

dq

A named series of quantiles at which confidence interval bounds will be calculated.

• "abrem" Default. This is the original default by Jurgen Symynck for predecessor package abrem it produces evenly spaced points across the y limits of a weibull canvas attempting to hold a constant number of points (see num_dq below).

• "minitab" Quantiles matching Minitab(TM) unchangeable defaults (27 values).

• "supersmith" Quantiles for comparison with SuperSMITH(TM) (limit of 15 values)

• "user" Provides for a user defined series of quantiles. (see user_dq below).

num_dq

The number of points used for the "abrem" dq determination.

user_dq

A vector of quantiles set by user. Default c(seq(.01,.09,by=.01),seq(.10,.90,by=.10),seq(.91,.99, by=.01)).

ci

The double-sided confidence interval, also chi sq confidence level for likelihood ratio. Must be in a range <1 && >0, default is 0.9.

blife.pts

The probability points at which to report Blife on legend.

Specific controls for pivotal analysis only

• seed The RNG seed integer such that results are duplicated between runs, default is 1234.

• S The number of samples to be run during pivotal analysis, default is 1e4.

Specific controls for likelihood ratio contour and bounds only

• dof The degrees of freedom, dof=1 (default) for confidence interval, dof=2 for comparison.

• ptDensity The number of points calculated to form the contour outline, default is 120.

General graphical options

Graphical control for fitted lines, confidence bounds, or contours can be set at wblr, wblr.fit, or wblr.conf functions for individual object control. See par

• col Color defaults to "black".

• lty Line type, defaults to "solid".

• lwd Line width defaults to 2.

Graphical controls typically used with plot or plot.wblr

• canvas The plotting canvas to be used. This does not necessarily have to match the fit distribution. Only "weibull" (default) or "lognormal" are recognized.

• mar Margins defaults to c(5.1,4.1,5.1,2.1),.

• main Title, defaults to "Probability Plot".

• main.contour Contour plot title defaults to "Contour Plot".

• sub Subtitle defaults to NULL.

• sub.contour Contour subtitle defaults to NULL.

• xlim Plot x limits override to be presented as a vector c(lo,hi), default NULL.

• ylim Plot y limits override to be presented as a vector c(lo,hi), default NULL.

• xlab X axis label defaults to "Time To Failure".

• ylab Y axis label defaults to "Unreliability [%]".

• coordinate.text.size default 0.7.

• signif Used to control display of numbers in Legend, default 4.

• col.grid Color for chart gridlines defaults "grey".

• is.plot.grid default TRUE.

• is.plot.fit default TRUE.

• is.plot.pp default TRUE.

• is.plot.ppcoordinates default FALSE.

• is.plot.legend default TRUE.

• legend.position default "bottomright". See legend Details.

• legend.inset default c(0,0). legend inset values are fractions of graph width and height.

• legend.text.size default 0.7.

• label defaults to "".

• in.legend default TRUE.

• in.legend.blives default TRUE.

• in.legend.gof default TRUE.

• is.plot.cb default TRUE.

• persistent default TRUE.

Examples

## backup options ##
wblr.defaults <- options.wblr()

## setting new options ##
options.wblr(S=5e5,ci=0.99)


## listing options ##
options.wblr()
options.wblr()$main

## restore options ##
options.wblr(wblr.defaults)

WeibullR documentation built on June 26, 2022, 1:06 a.m.