Add residual variability based on parameter estimates
Usage
addResVar(
data,
path.ext,
prop = NULL,
add = NULL,
log = FALSE,
par.type = "SIGMA",
trunc0 = TRUE,
scale.par,
subset,
seed,
col.ipred = "IPRED",
col.ipredvar = "IPREDVAR",
as.fun
)
Arguments
- data
A data set containing indiviudual predictions. Often a result of NMsim.
- path.ext
Path to the ext file to take the parameter estimates from.
- prop
Parameter number of parameter holding variance of the proportional error component. If ERR(1) is used for proportional error, use prop=1. Can also refer to a theta number.
- add
Parameter number of parameter holding variance of the additive error component. If ERR(1) is used for additive error, use add=1. Can also refer to a theta number.
- log
Should the error be added on log scale? This is used to obtain an exponential error distribution.
- par.type
Use "sigma" if variances are estimated with the SIGMA matrix. Use "theta" if THETA parameters are used. See `scale.par` too.
- trunc0
If log=FALSE, truncate simulated values at 0? If trunc0, returned predictions can be negative.
- scale.par
Denotes if parmeter represents a variance or a standard deviation. Allowed values and default value depends on `par.type`.
if par.type="sigma" only "var" is allowed.
if par.type="theta" allowed values are "sd" and "var". Default is "sd".
- subset
A character string with an expression denoting a subset in which to add the residual error. Example: subset="DVID=='A'"
- seed
A number to pass to set.seed() before simulating. Default is to generate a seed and report it in the console. Use seed=FALSE to avoid setting the seed (if you prefer doing it otherwise).
- col.ipred
The name of the column containing individual predictions.
- col.ipredvar
The name of the column to be created by addResVar to contain the simulated observations (individual predictions plus residual error).
- as.fun
The default is to return data as a data.frame. Pass a function (say `tibble::as_tibble`) in as.fun to convert to something else. If data.tables are wanted, use as.fun="data.table". The default can be configured using NMdataConf.
Examples
if (FALSE) { # \dontrun{
## based on SIGMA
simres.var <- addResVar(data=simres,
path.ext = "path/to/model.ext",
prop = 1,
add = 2,
par.type = "SIGMA",
log = FALSE)
## If implemented using THETAs
simres.var <- addResVar(data=simres,
path.ext = "path/to/model.ext",
prop = 8, ## point to elements in THETA
add = 9, ## point to elements in THETA
par.type = "THETA",
log = FALSE)
} # }