Create factor variable from an existing (non-double) variable

genFactor(dtName, varname, labels = NULL, prefix = "f", replace = FALSE)

Arguments

dtName

Data table with columns.

varname

Name of field(s) to be converted.

labels

Factor level labels. If not provided, the generated factor levels will be used as the labels. Can be a vector (if only one new factor or all factors have the same labels) or a list of character vectors of the same length as varname.

prefix

By default, the new field name will be a concatenation of "f" and the old field name. A prefix string can be provided.

replace

If replace is set to TRUE (defaults to FALSE) the field referenced varname will be removed.

Examples


# First example:

def <- defData(varname = "cat", formula = ".2;.3;.5", dist = "categorical")
def <- defData(def, varname = "x", formula = 5, variance = 2)

dx <- genData(200, def)
dx
#>       id cat        x
#>   1:   1   3 3.914439
#>   2:   2   3 4.482196
#>   3:   3   3 2.031990
#>   4:   4   1 5.646096
#>   5:   5   2 3.280469
#>  ---                 
#> 196: 196   3 4.031803
#> 197: 197   3 3.423400
#> 198: 198   2 5.876663
#> 199: 199   2 5.303516
#> 200: 200   2 6.232819

dx <- genFactor(dx, "cat", labels = c("one", "two", "three"))
dx
#>       id cat        x  fcat
#>   1:   1   3 3.914439 three
#>   2:   2   3 4.482196 three
#>   3:   3   3 2.031990 three
#>   4:   4   1 5.646096   one
#>   5:   5   2 3.280469   two
#>  ---                       
#> 196: 196   3 4.031803 three
#> 197: 197   3 3.423400 three
#> 198: 198   2 5.876663   two
#> 199: 199   2 5.303516   two
#> 200: 200   2 6.232819   two

# Second example:

dx <- genData(10)
dx <- trtAssign(dtName = dx, 2, grpName = "studyArm")
dx <- genFactor(dx, varname = "studyArm", labels = c("control", "treatment"), prefix = "t_")
dx
#>     id studyArm t_studyArm
#>  1:  1        1  treatment
#>  2:  2        0    control
#>  3:  3        1  treatment
#>  4:  4        0    control
#>  5:  5        0    control
#>  6:  6        1  treatment
#>  7:  7        0    control
#>  8:  8        0    control
#>  9:  9        1  treatment
#> 10: 10        1  treatment