plot.cpd.PwrGSD: Plot Method for cpd.PwrGSD objects
Description
Creates a trellis plot of type II error probability and
power at each interim analysis, stacked, versus an effect size
variable, conditioned upon levels of up to two factors.
Usage
# S3 method for cpd.PwrGSD
plot(x, formula, subset, na.action,…)
Arguments
x
an object of class cpd.PwrGSD
formula
a one sided formula of the form ~ effect | f1
or ~ effect | f1 * f2 where effect, f1, and
f2 are variables in the indexing dataframe descr, or
the special variable stat which may be used when there are
multiple test statistics per component of Elements. See
the example in the documentation for cpd.PwrGSD
subset
the plot can be applied to a subset of rows of
descr via a logical expression on its variables in
combination with the special variable, stat when applicable.
na.action
a na.action method for handling NA
values
…
other parameters to pass to the R function coplot
usually not neccesary
Value
Returns the object, x, invisibly
References
Chambers, J. M. (1992)
Data for models.
Chapter 3 of Statistical Models in S
eds J. M. Chambers and T. J. Hastie, Wadsworth \& Brooks/Cole.
Cleveland, W. S. (1993) Visualizing Data. New Jersey: Summit Press.