plotSafeTDesignSampleSizeProfile {safestats}

Plots the Sample Sizes Necessary for a Tolerable Alpha and Beta as a Function of deltaMin

Description

For given tolerable alpha and beta, (1) the planned sample sizes to using a safe test, (2) the frequentist test, and (3) the average sample size necessary due to optional stopping are plotted as a function of the minimal clinically relevant standardised effect size deltaMin.

Usage

plotSafeTDesignSampleSizeProfile(
  alpha = 0.05,
  beta = 0.2,
  nMax = 100,
  lowDeltaMin = 0.1,
  highDeltaMin = 1,
  stepDeltaMin = 0.1,
  testType = c("oneSample", "paired", "twoSample"),
  alternative = c("twoSided", "greater", "less"),
  ratio = 1,
  nSim = 1000L,
  nBoot = 1000L,
  seed = NULL,
  pb = TRUE,
  freqPlot = FALSE,
  ...
)

Arguments

alpha

numeric in (0, 1) that specifies the tolerable type I error control –independent of n– that the designed test has to adhere to. Note that it also defines the rejection rule e10 > 1/alpha.

beta

numeric in (0, 1) that specifies the tolerable type II error control necessary to calculate both the sample sizes and deltaS, which defines the test. Note that 1-beta defines the power.

nMax

numeric, the maximum number of samples one has budget for to collect data.

lowDeltaMin

numeric, lowest value for deltaMin of interest

highDeltaMin

numeric, largest value for deltaMin of interest

stepDeltaMin

numeric, step size between lowDeltaMin and highDeltaMin

testType

either one of "oneSample", "paired", "twoSample".

alternative

a character string specifying the alternative hypothesis must be one of "twoSided" (default), "greater" or "less".

ratio

numeric > 0 representing the randomisation ratio of condition 2 over condition 1. If testType is not equal to "twoSample", or if nPlan is of length(1) then ratio=1.

nSim

integer > 0, the number of simulations needed to compute power or the number of samples paths for the safe z test under continuous monitoring.

nBoot

integer > 0 representing the number of bootstrap samples to assess the accuracy of approximation of the power, the number of samples for the safe z test under continuous monitoring, or for the computation of the logarithm of the implied target.

seed

integer, seed number.

pb

logical, if TRUE, then show progress bar.

freqPlot

logical, if TRUE plot frequentist sample size profiles.

...

further arguments to be passed to or from methods, but mainly to perform do.calls.

Value

Returns a list that contains the planned sample size needed for the frequentist and safe tests as a function of the minimal clinically relevant effect sizes. The returned list contains at least the following components:

alpha

the tolerable type I error provided by the user.

beta

the tolerable type II error provided by the user.

maxN

the largest number of samples provided by the user.

deltaDomain

vector of the domain of deltaMin.

allN1PlanFreq

vector of the planned sample sizes needed for the frequentist test corresponding to alpha and beta.

allN1PlanSafe

vector of the planned sample sizes needed for the safe test corresponding to alpha and beta.

allDeltaS

vector of safe test defining deltaS.

Examples

plotSafeTDesignSampleSizeProfile(nSim=1e2L)