Build a fahb_problem object — fahb

Given a trial design and a set of model hyperparameters, build an object of class fahb_problem.

Usage

fahb_problem(
  N = 320,
  m = 20,
  t = 0.5,
  n_ext = NULL,
  m_ext = NULL,
  rel_thr = 1.2,
  so_hps = c(30, 2.85),
  mean_rr_hps = c(2, 0.329),
  sd_rr_hps = c(30, 100)
)

Arguments

N: target sample size.
m: number of recruiting sites.
t: timing of the pilot analysis in years.
n_ext: number of participants to recruit to an external pilot.
m_ext: number of sites to open in an external pilot.
rel_thr: threshold which discriminates feasible and infeasible trials, as a multiple of the expected time to recruit.
so_hps: site opening rate hyperparameters (shape and rate for a Gamma prior).
mean_rr_hps: mean site recruitment rate hyperparameters (mean and sd for a lognormal prior).
sd_rr_hps: variance in site recruitment rates hyperparameters (shape and rate for a Gamma prior).

Value

an object of class fahb_problem

Examples

fahb_problem()
#> $N
#> [1] 320
#> 
#> $m
#> [1] 20
#> 
#> $t
#> [1] 0.5
#> 
#> $n_ext
#> NULL
#> 
#> $m_ext
#> NULL
#> 
#> $internal
#> [1] TRUE
#> 
#> $rel_thr
#> [1] 1.2
#> 
#> $exp_T
#> [1] 3.001289
#> 
#> $thr
#> [1] 3.601546
#> 
#> $so_hp_a
#> [1] 30
#> 
#> $so_hp_b
#> [1] 2.85
#> 
#> $mean_rr_hp_a
#> [1] 2
#> 
#> $mean_rr_hp_b
#> [1] 0.329
#> 
#> $sd_rr_hp_a
#> [1] 30
#> 
#> $sd_rr_hp_b
#> [1] 100
#> 
#> $sims
#> NULL
#> 
#> attr(,"class")
#> [1] "fahb_problem"