modify: Modify binary sequential boundary

Description

Modify several different aspects of a binary sequential boundary. Most modifications do not change the stopping boundaries. The exceptions are 'missN', which allows modifications for missing assessments, and 'closeout', which allows for early stopping of the trial for administrative reasons (i.e., reasons that do not depend on the responses in the trial). Other modifications possible: level of the confidence intervals (using tsalpha, conf.level, or alternative), which boundaries are binding (i.e., can change from a boundary with binding futility boundaries to one with non-binding futility boundaries), null hypothesis value (theta0), and whether the confidence intervals should match the non-binding futility p-values on the superiority boundaries (cipMatch).

Usage

modify(b, missN = NULL, theta0 = NULL, tsalpha = NULL,
    conf.level = NULL, alternative = NULL, cipMatch = TRUE,
    binding = NULL, closeout=NULL,  ...)

Value

an object of class boundEst

Arguments

b: an object of class boundEst
missN: a vector of missed assessments
theta0: null hypothesis probability of success
tsalpha: vector of length 2 with nominal significance level, if not NULL overrides conf.level and alternative
conf.level: confidence level, ignored if tsalpha is not NULL
alternative: character, alternative hypothesis, either 'less', 'greater' or 'two.sided'
cipMatch: logical, for non-binding futility boundaries, should CI match the p-values on the binding boundary
binding: character, which sides are binding: 'both', 'upper', or 'lower'
closeout: total number of trials at early closeout
...: other parameters passed

Examples

Run this code

b<-designOBF(50)
bmod<-modify(b,missN=30:36)
par(mfrow=c(2,1))
plot(b)
plot(bmod)

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