blindrecalc (version 1.1.0)

n_dist,FarringtonManning-method: Distribution of the Sample Size

Description

Calculates the distribution of the total sample sizes of designs with blinded sample size recalculation for different values of the nuisance parameter or of n1.

Usage

# S4 method for FarringtonManning
n_dist(
  design,
  n1,
  nuisance,
  summary,
  plot,
  allocation = c("exact", "approximate"),
  ...
)

Value

Summary and/or plot of the sample size distribution for each nuisance parameter and every value of n1.

Arguments

design

Object of class FarringtonManning created by setupFarringtonManning.

n1

Either the sample size of the first stage (if recalculation = TRUE or the total sample size (if recalculation = FALSE).

nuisance

Value of the nuisance parameter in (0,1). For the Farrington-Manning test this is the overall response rate.

summary

Is a summary of the sample size distribution desired? Otherwise, a vector with sample sizes is returned.

plot

Should a plot of the sample size distribution be drawn?

allocation

Whether the allocation ratio should be preserved exactly (exact) or approximately (approximate).

...

Further optional arguments.

Details

Only sample sizes that occur with a probability of at least 0.01 are considered.

The method is only vectorized in either nuisance or n1.

Examples

d <- setupFarringtonManning(alpha = 0.025, beta = 0.2, r = 1,
                            delta = 0, delta_NI = 0.25)
n_dist(d, n1 = 30, nuisance = 0.2, summary = TRUE, plot = FALSE)