data_set: Select and modify a data set for simulation

In mrgsolve: Simulate from ODE-Based Models

Select and modify a data set for simulation

Description

The input data set (data_set) is a data frame that specifies observations, model events, and / or parameter values for a population of individuals.

Usage

data_set(x, data, ...)

## S4 method for signature 'mrgmod,data.frame'
data_set(
  x,
  data,
  .subset = TRUE,
  .select = TRUE,
  object = NULL,
  need = NULL,
  ...
)

## S4 method for signature 'mrgmod,ANY'
data_set(x, data, ...)

## S4 method for signature 'mrgmod,ev'
data_set(x, data, ...)

## S4 method for signature 'mrgmod,missing'
data_set(x, object, ...)

Arguments

x	a model object.
data	input data set as a data frame.
...	other arguments passed along when object is a function.
.subset	an unquoted expression passed to dplyr::filter(); retain only certain rows in the data set
.select	passed to dplyr::select(); retain only certain columns in the data set; this should be the result of a call to dplyr::vars().
object	character name of an object existing in ⁠$ENV⁠ to use for the data set.
need	passed to inventory().

Details

Input data sets are R data frames that can include columns with any valid name, however columns with selected names are treated specially by mrgsolve and incorporated into the simulation.

ID specifies the subject ID and is required for every input data set.

When columns have the same name as parameters (⁠$PARAM⁠ or ⁠$INPUT⁠ in the model specification file), the values in those columns will be used to update the corresponding parameter as the simulation progresses.

Input data set may include the following columns related to PK dosing events: TIME, CMT, AMT, RATE, II, ADDL, SS. Both ID and TIME are required columns in the input data set unless ⁠$PRED⁠ is in use. Lower case PK dosing column names including time, cmt, amt, rate, ii, addl, ss are also recognized. However, an error will be generated if a mix of both upper case and lower case columns in this family are found. Use the functions lctran() and uctran() to convert between upper and lower case naming for these data items.

TIME is the observation or event time, CMT is the compartment number (see init()), AMT is the dosing amount, RATE is the infusion rate, II is the dosing interval, ADDL specifies additional doses to administer, and ss is a flag indicating that the system should be advanced to a pharmacokinetic steady state prior to administering the dose. These column names operate similarly to other non-linear mixed effects modeling software.

EVID is an integer value specifying the ID of an event record. Values include:

• 0: observation

• 1: dose event, either bolus or infusion

• 2: other-type event; in mrgsolve, this functions like an observation record, but a discontinuity is created in the simulation at the time of the event (i.e., the ODE solver will stop and restart at the time of the event)

• 3: reset the system

• 4: reset the system and dose

• 8: replace the amount in a compartment

For all EVID greater than 0, a discontinuity is created in the simulation, as described for ⁠EVID 2⁠.

An error will be generated when mrgsolve detects that the data set is not sorted by time within an individual. mrgsolve does not allow time to be reset to zero on records where EVID is set to 4 (reset and dose).

Only numeric data can be brought in to the problem. Any non-numeric data columns will be dropped with warning. See numerics_only(), which is used to prepare the data set.

An error will be generated if any parameter columns in the input data set contain missing values (NA). Likewise, and error will be generated if missing values are found in the following columns: ID, time/TIME, rate/RATE.

See exdatasets for several example data sets that are provided by mrgsolve.

See Also

idata_set(), ev(), valid_data_set(), valid_idata_set(), lctran(), uctran().

Examples

mod <- mrgsolve::house()

data <- expand.ev(ID = seq(3), amt = c(10, 20))

mod %>% data_set(data, ID > 1) %>% mrgsim()

data(extran1)
head(extran1)

mod %>% data_set(extran1) %>% mrgsim()
mod %>% mrgsim(data = extran1)

mrgsolve documentation built on Oct. 18, 2024, 5:12 p.m.