idata_set: Select and modify a idata set for simulation

In mrgsolve: Simulate from ODE-Based Models

Select and modify a idata set for simulation

Description

The individual data set (idata_set) is a data frame with one row for each individual in a population, specifying parameters and other individual-level data.

Usage

idata_set(x, data, ...)

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

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

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

Arguments

x	model object.
data	a data set that can be coerced to 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

The idata_set is a data frame that specifies individual-level data for the problem. An ID column is required and there can be no more than one row in the data frame for each individual.

In most cases, the columns in the idata_set have the same names as parameters in the param() list. When this is the case, the parameter set is updated as the simulation proceeds once at the start of each individual. The idata_set can also be used to set initial conditions for each individual: for a compartment called CMT, make a column in idata_set called CMT_0 and make the value the desired initial value for that compartment. Note that this initial condition will be overridden if you also set the CMT_0 in ⁠$MAIN⁠ (⁠$PK⁠).

The most common application of idata_set is to specify a population or batch of simulations to do. We commonly use idata_set with an event object (see ev()). In that case, the event gets applied to each individual in the idata_set.

It is also possible to provide both a data_set and a idata_set. In this case, the idata_set is used as a parameter lookup for IDs found in the data_set. Remember in this case, it is the data_set (not the idata_set) that determines the number of individuals in the simulation.

An error will be generated if any parameter columns in the input idata set contain NA.

See Also

data_set(), ev()

Examples

mod <- mrgsolve::house()

data(exidata)

exidata

mod %>% 
  idata_set(exidata, ID <= 2) %>% 
  ev(amt = 100) %>%
  mrgsim() %>% 
  plot()

mod %>% 
  idata_set(exidata) %>% 
  ev(amt = 100) %>%
  mrgsim()

mod %>% ev(amt = 100) %>% mrgsim(idata=exidata) 

mrgsolve documentation built on Aug. 22, 2025, 9:12 a.m.