blindrecalc: n_dist.ChiSquare – R documentation

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n_dist.ChiSquare

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 signature 'ChiSquare'
n_dist(
  design,
  n1,
  nuisance,
  summary = TRUE,
  plot = FALSE,
  allocation = c("exact", "approximate"),
  ...
)

Arguments

`design`	Object of class `ChiSquare` created by `setupChiSquare`.
`n1`	Either the sample size of the first stage (if `recalculation = TRUE` or the toal sample size (if `recalculation = FALSE`).
`nuisance`	Value of the nuisance parameter. For the Chi-Squared test this is the overall response rate.
`summary`	Logical. If `TRUE` (default) a summary of the sample size distribution is printed. If `FALSE` all sample sizes are printed.
`plot`	Should a plot of the sample size distribution be drawn?
`allocation`	Whether the allocation ratio should be preserved exactly (`exact`) or approximately (`approximate` or `kf_approx`). `appproximate` uses the unrounded calculated sample size in the sample size recalculation, `kf_approx` rounds the sample size to the next integer.
`...`	Further optional arguments.

Details

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

The method is only vectorized in either nuisance or n1.

Value

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

Examples

d <- setupChiSquare(alpha = 0.025, beta = 0.2, r = 1, delta = 0.2)
  n_dist(d, n1 = 20, nuisance = 0.25, summary = TRUE, plot = FALSE)

blindrecalc

Blinded Sample Size Recalculation

v0.1.2

MIT + file LICENSE

Authors

Lukas Baumann [aut], Maximilian Pilz [aut, cre], Institute of Medical Biometry and Informatics - University of Heidelberg [cph]

Initial release