Periodic inspection observation scheme

Creates an observation functor for periodic inspections at intervals of width delta. The failure time is known only to lie within the inspection interval containing it (interval-censored). Systems surviving past tau are right-censored.

Usage

observe_periodic(delta, tau = Inf)

Arguments

delta

Inspection interval width (positive numeric).

tau

Study end time / right-censoring time (positive numeric or Inf for no right-censoring).

Value

Observation functor: function(t_true) returning a list with t (interval lower bound or tau), omega ("interval" or "right"), and t_upper (interval upper bound or NA).

Examples

obs <- observe_periodic(delta = 10, tau = 100)
obs(25)   # interval: list(t = 20, omega = "interval", t_upper = 30)
#> $t
#> [1] 20
#> 
#> $omega
#> [1] "interval"
#> 
#> $t_upper
#> [1] 30
#> 
obs(150)  # right:    list(t = 100, omega = "right", t_upper = NA)
#> $t
#> [1] 100
#> 
#> $omega
#> [1] "right"
#> 
#> $t_upper
#> [1] NA
#>