Create an event table object

Source: R/et.R

Initializes an object of class ‘EventTable’ with methods for adding and querying dosing and observation records

eventTable(amount.units = NA, time.units = NA)

Arguments

amount.units

string denoting the amount dosing units, e.g., “mg”, “ug”. Default to NA to denote unspecified units. It could also be a solved rxode2 object. In that case, eventTable(obj) returns the eventTable that was used to solve the rxode2 object.

time.units

string denoting the time units, e.g., “hours”, “days”. Default to "hours".

An eventTable is an object that consists of a data.frame storing ordered time-stamped events of an (unspecified) PK/PD dynamic system, units (strings) for dosing and time records, plus a list of functions to add and extract event records.

Currently, events can be of two types: dosing events that represent inputs to the system and sampling time events that represent observations of the system with ‘amount.units’ and ‘time.units’, respectively.

Value

A modified data.frame with the following accessible functions:

  • get.EventTable() returns the current event table

  • add.dosing() adds dosing records to the event table.

  • get.dosing() returns a data.frame of dosing records.

  • clear.dosing() clears or deletes all dosing from event table

  • `add.sampling() adds sampling time observation records to the event table.

  • get.sampling()returns a data.frame of sampled observation records.

  • clear.sampling() removes all sampling from event table.

  • get.obs.rec() returns a logical vector indicating whether each event record represents an observation or not.

  • get.nobs() returns the number of observation (not dosing) records.

  • get.units() returns a two-element character vector with the dosing and time units, respectively

  • copy() makes a copy of the current event table. To create a copy of an event table object use qd2 <- qd$copy()

  • expand() Expands the event table for multi-subject solving. This is done by qd$expand(400) for a 400 subject data expansion

See also

et()

Author

Matthew Fidler, Melissa Hallow and Wenping Wang

Examples

# create dosing and observation (sampling) events
# QD 50mg dosing, 5 days followed by 25mg 5 days
#
qd <- eventTable(amount.units = "mg", time.units = "days")
#
qd$add.dosing(dose = 50, nbr.doses = 5, dosing.interval = 1, do.sampling = FALSE)
#
# sample the system's drug amounts hourly the first day, then every 12 hours
# for the next 4 days
qd$add.sampling(seq(from = 0, to = 1, by = 1 / 24))
qd$add.sampling(seq(from = 1, to = 5, by = 12 / 24))
#
# print(qd$get.dosing())     # table of dosing records
print(qd$get.nobs()) # number of observation (not dosing) records
#> [1] 34
#
# BID dosing, 5 days
bid <- eventTable("mg", "days") # only dosing
bid$add.dosing(
  dose = 10000, nbr.doses = 2 * 5,
  dosing.interval = 12, do.sampling = FALSE
)
#
# Use the copy() method to create a copy (clone) of an existing
# event table (simple assignments just create a new reference to
# the same event table object (closure)).
#
bid.ext <- bid$copy() # three-day extension for a 2nd cohort
bid.ext$add.dosing(
  dose = 5000, nbr.doses = 2 * 3,
  start.time = 120, dosing.interval = 12, do.sampling = FALSE
)

# You can also use the Piping operator to create a table

qd2 <- eventTable(amount.units = "mg", time.units = "days") %>%
  add.dosing(dose = 50, nbr.doses = 5, dosing.interval = 1, do.sampling = FALSE) %>%
  add.sampling(seq(from = 0, to = 1, by = 1 / 24)) %>%
  add.sampling(seq(from = 1, to = 5, by = 12 / 24))
# print(qd2$get.dosing())     # table of dosing records
print(qd2$get.nobs()) # number of observation (not dosing) records
#> [1] 34

# Note that piping with %>% will update the original table.

qd3 <- qd2 %>% add.sampling(seq(from = 5, to = 10, by = 6 / 24))
print(qd2$get.nobs())
#> [1] 34
print(qd3$get.nobs())
#> [1] 55