Draw samples from a two-stage design

Source: R/TwoStageDesign.R

simulate allows to draw samples from a given TwoStageDesign.

# S4 method for TwoStageDesign,numeric
simulate(object, nsim, dist, theta, seed = NULL, ...)

Arguments

object

TwoStageDesign to draw samples from

nsim

number of simulation runs

dist

data distribution

theta

location parameter of the data distribution

seed

random seed

...

further optional arguments

Value

simulate() returns a data.frame with nsim

rows and for each row (each simulation run) the following columns

  • theta The effect size

  • n1 First-stage sample size

  • c1f Stopping for futility boundary

  • c1e Stopping for efficacy boundary

  • x1 First-stage outcome

  • n2 Resulting second-stage sample size after observing x1

  • c2 Resulting second-stage decision-boundary after observing x1

  • x2 Second-stage outcome

  • reject Decision whether the null hypothesis is rejected or not

See also

TwoStageDesign

Examples

design <- TwoStageDesign(25, 0, 2, 25, 2, order = 5)
# draw samples assuming two-armed design
simulate(design, 10, Normal(), .3, 42)
#>    theta n1 c1f c1e        x1 n2   c2         x2 reject
#> 1    0.3 25   0   2 2.4316186  0 -Inf  1.3048697   TRUE
#> 2    0.3 25   0   2 0.4959620 25    2  3.3473056   TRUE
#> 3    0.3 25   0   2 1.4237886 25    2 -0.3282005  FALSE
#> 4    0.3 25   0   2 1.6935228 25    2  0.7818714  FALSE
#> 5    0.3 25   0   2 1.4649285 25    2  0.9273388  FALSE
#> 6    0.3 25   0   2 0.9545357 25    2  1.6966106  FALSE
#> 7    0.3 25   0   2 2.5721822  0 -Inf -0.2842529   TRUE
#> 8    0.3 25   0   2 0.9660011 25    2 -1.5957952  FALSE
#> 9    0.3 25   0   2 3.0790839  0 -Inf -2.4404669   TRUE
#> 10   0.3 25   0   2 0.9979461 25    2  2.3807735   TRUE