Event objects for simulating PK and other interventions

An event object specifies dosing or other interventions that get implemented during simulation. Event objects do similar things as data_set, but simpler and easier to create.

ev(x, ...)

# S4 method for class 'mrgmod'
ev(x, object = NULL, ...)

# S4 method for class 'missing'
ev(
  time = 0,
  amt = 0,
  evid = 1,
  cmt = 1,
  ID = numeric(0),
  replicate = TRUE,
  until = NULL,
  tinf = NULL,
  realize_addl = FALSE,
  ...
)

# S4 method for class 'ev'
ev(x, realize_addl = FALSE, ...)

Arguments

x

a model object.

...

other items to be incorporated into the event object; see Details.

object

an event object to be added to a model object.

time

event time.

amt

dose amount.

evid

event ID.

cmt

compartment number or name.

ID

subject ID.

replicate

logical; if TRUE, events will be replicated for each individual in ID.

until

the expected maximum observation time for this regimen; doses will be scheduled up to, but not including, the until time; see Examples.

tinf

infusion time; if greater than zero, then the rate item will be derived as amt/tinf.

realize_addl

if FALSE (default), no change to addl doses. If TRUE, addl doses are made explicit with realize_addl().

Value

ev() returns an event object.

Details

• Required items in events objects include time, amt, evid and cmt.

• If not supplied, evid is assumed to be 1.

• If not supplied, cmt is assumed to be 1.

• If not supplied, time is assumed to be 0.

• If amt is not supplied, an error will be generated.

• If total is supplied, then addl will be set to total-1.

• Other items can include ii, ss, and addl (see data_set for details on all of these items).

• ID may be specified as a vector.

• If replicate is TRUE (default), then the events regimen is replicated for each ID; otherwise, the number of event rows must match the number of IDs entered.

See also

evd(), ev_rep(), ev_days(), ev_repeat(), ev_assign(), ev_seq(), mutate.ev(), as.ev(), as.evd(), ev_methods.

Examples

mod <- mrgsolve::house()

mod <- mod %>% ev(amt = 1000, time = 0, cmt = 1)

loading <- ev(time = 0, cmt = 1, amt = 1000)

maint <- ev(time = 12, cmt = 1, amt = 500, ii = 12, addl = 10)

c(loading, maint)
#> Events:
#>   time  amt cmt evid ii addl
#> 1    0 1000   1    1  0    0
#> 2   12  500   1    1 12   10

reduced_load <- dplyr::mutate(loading, amt = 750)

# Three additional doses in this case
e <- ev(amt = 100, ii = 4*7, until = 16*7)
e
#> Events:
#>   time amt ii addl cmt evid
#> 1    0 100 28    3   1    1
# Last dose is given at 84
realize_addl(e)
#> Events:
#>   time amt ii addl cmt evid
#> 1    0 100  0    0   1    1
#> 2   28 100  0    0   1    1
#> 3   56 100  0    0   1    1
#> 4   84 100  0    0   1    1

# Four additional doses with last at 112 in this case
e <- ev(amt = 100, ii = 4*7, until = 16*7 + 0.001)
realize_addl(e)
#> Events:
#>   time amt ii addl cmt evid
#> 1    0 100  0    0   1    1
#> 2   28 100  0    0   1    1
#> 3   56 100  0    0   1    1
#> 4   84 100  0    0   1    1
#> 5  112 100  0    0   1    1