simstudy (version 0.7.0)

addPeriods: Create longitudinal/panel data

Description

Create longitudinal/panel data

Usage

addPeriods(
  dtName,
  nPeriods = NULL,
  idvars = "id",
  timevars = NULL,
  timevarName = "timevar",
  timeid = "timeID",
  perName = "period"
)

Value

An updated data.table that that has multiple rows per observation in dtName

Arguments

dtName

Name of existing data table

nPeriods

Number of time periods for each record

idvars

Names of index variables (in a string vector) that will be repeated during each time period

timevars

Names of time dependent variables. Defaults to NULL.

timevarName

Name of new time dependent variable

timeid

Variable name for new index field. Defaults to "timevar"

perName

Variable name for period field. Defaults to "period"

Examples

tdef <- defData(varname = "T", dist = "binary", formula = 0.5)
tdef <- defData(tdef, varname = "Y0", dist = "normal", formula = 10, variance = 1)
tdef <- defData(tdef, varname = "Y1", dist = "normal", formula = "Y0 + 5 + 5 * T", variance = 1)
tdef <- defData(tdef, varname = "Y2", dist = "normal", formula = "Y0 + 10 + 5 * T", variance = 1)

dtTrial <- genData(5, tdef)
dtTrial

dtTime <- addPeriods(dtTrial,
  nPeriods = 3, idvars = "id",
  timevars = c("Y0", "Y1", "Y2"), timevarName = "Y"
)
dtTime

# Varying # of periods and intervals - need to have variables
# called nCount and mInterval

def <- defData(varname = "xbase", dist = "normal", formula = 20, variance = 3)
def <- defData(def, varname = "nCount", dist = "noZeroPoisson", formula = 6)
def <- defData(def, varname = "mInterval", dist = "gamma", formula = 30, variance = .01)
def <- defData(def, varname = "vInterval", dist = "nonrandom", formula = .07)

dt <- genData(200, def)
dt[id %in% c(8, 121)]

dtPeriod <- addPeriods(dt)
dtPeriod[id %in% c(8, 121)] # View individuals 8 and 121 only