There are several classes that represent binary sequential boundaries. The most simple is the abparms class, then comes the bounds class (which contains abparms), then comes boundNBF class (which contains bound class), or boundEst class (which contains bounds class), then comes boundNBFEst (which contains boundNBF). See details for which slots go with which classes.
Nk:vector of number of samples at boundary stopping points
a:vector for lower bound, stop if S out of Nk is less than or equal a. NA denotes do not stop.
b:vector for upper bound, stop if S out of Nk is greater than or equal b. NA denotes do not stop.
binding:character specifying which boundary section is binding, either 'both', 'upper', or 'lower'
alternative:character specifying alternative, 'two.sided', 'less', or 'greater'
N:vector of number of samples at boundary stopping points
S:vector of number of sucesses at boundary stopping points
K:vector of number of ways to get to each boundary point
order:vector of ordering of points
UL:character vector denoting part of boundary, either 'lower' or 'upper' or 'end'
estimate:vector of estimates of theta, probability of success
lower:vector of lower confidence intervals for theta
upper:vector of upper confidence intervals for theta
conf.level:confidence level associated with confidence intervals
alpha:error on either side
theta0:null value for theta
plower:vector of lower p-values
pupper:vector of upper p-values
pval:vector of p-values as directed by alternative slot
There is a plot and a points method for boundEst objects.
Jenn Kirk, Michael P. Fay
The simplest representation of a binary sequential
boundary is the abparms class, represented by a vector of
the total number of trials (Nk) where to stop, and denoting
stopping when number of sucesses, S, is S>=b or S<= a.
One sided boundaries can be represented by all NA values
for either a or b. Often times a two-sided boundary
treats one side as a superiority boundary which must be
stopped if crossed (a binding boundary), while the other
side of the boundary is a futility boundary which may be
ignored (a non-binding boundary). For example when
binding='upper', then p-values for the upper boundary are
calculated as if the lower boundaries are ignored if
crossed and stopping happens on the lower side at max(Nk)
instead, while the p-values for the lower and end
boundary points are calculated using all (lower,upper and
end) boundaries.
Next is the bound class which
adds the slots N (number of trials at each boundary
point), S (number of sucesses at each point), K (number
of ways to get to each point), order (ordering of points
for p-value calculations), UL('upper','lower' or 'end').
new("abparms",Nk=200)
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