Execution time is very long or is impossible

[DanChaltiel]

Hi,

Thank you for this very nice package.

The following code takes a rather long time:

createGrid(p0 = 0.15, p1 = 0.3, alpha = 0.05, beta = 0.2) %>%
  augmentGrid() %>%
  obtainDesign(mander = FALSE)

Moreover, with p0=0.2, it ends with the following error:

Error in `expand_grid()`:
! Long vectors are not yet supported. Expansion results in an allocation larger than 2^31-1 elements. Attempted allocation size was 30921809484.

Note that it is instantaneous to get the results of both cases online using http://cancer.unc.edu/biostatistics/program/ivanova/SimonsTwoStageDesign.aspx.

This other package also gives the same result (and is much faster):

remotes::install_github("IDDI-BE/PhIIdesign")
PhIIdesign::simon2stage(p0 = 0.15, pa = 0.3, alpha = 0.05, beta = 0.2, N_min=1, N_max=100)