tests/testthat/test_simulation.R

In IGPFrailty: Inverse Gaussian Process Degradation Models with Frailty

test_that("sim_igp simulates valid degradation paths", {
  sim_none <- sim_igp(n = 5, times = seq(0, 2, by = 0.5), theta = 1.5, eta = 10, frailty = "none", seed = 1)
  expect_equal(length(unique(sim_none$unit)), 5)
  expect_true(all(sim_none$degradation >= 0))
  
  sim_gam <- sim_igp(n = 5, times = seq(0, 2, by = 0.5), theta = 1.5, eta = 10, xi = 0.3, frailty = "gamma", seed = 1)
  expect_equal(length(unique(sim_gam$unit)), 5)
  expect_true(all(sim_gam$frailty_z > 0))
  
  sim_ig <- sim_igp(n = 5, times = seq(0, 2, by = 0.5), theta = 1.5, eta = 10, xi = 0.3, frailty = "ig", seed = 1)
  expect_equal(length(unique(sim_ig$unit)), 5)
  expect_true(all(sim_ig$frailty_z > 0))
})