genSynthetic {simstudy}

Generate synthetic data

Description

Synthetic data is generated from an existing data set

Usage

genSynthetic(dtFrom, n = nrow(dtFrom), vars = NULL, id = "id")

Arguments

dtFrom

Data table that contains the source data

n

Number of samples to draw from the source data. The default is number of records that are in the source data file.

vars

A vector of string names specifying the fields that will be sampled. The default is that all variables will be selected.

id

A string specifying the field that serves as the record id. The default field is "id".

Value

A data table with the generated data

Examples

### Create fake "real" data set

d <- defData(varname = "a", formula = 3, variance = 1, dist = "normal")
d <- defData(d, varname = "b", formula = 5, dist = "poisson")
d <- defData(d, varname = "c", formula = 0.3, dist = "binary")
d <- defData(d, varname = "d", formula = "a + b + 3*c", variance = 2, dist = "normal")

A <- genData(100, d, id = "index")

### Create synthetic data set from "observed" data set A:

def <- defDataAdd(varname = "x", formula = "2*b + 2*d", variance = 2)

S <- genSynthetic(dtFrom = A, n = 120, vars = c("b", "d"), id = "index")
S <- addColumns(def, S)