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
#> Key: <id>
#>         id   cat        x
#>      <int> <int>    <num>
#>   1:     1     1 6.173198
#>   2:     2     3 3.451851
#>   3:     3     2 4.505016
#>   4:     4     3 6.589504
#>   5:     5     2 1.835221
#>  ---                     
#> 196:   196     3 5.704497
#> 197:   197     1 4.854637
#> 198:   198     3 4.258349
#> 199:   199     3 4.017217
#> 200:   200     3 4.772752

dx <- genFactor(dx, "cat", labels = c("one", "two", "three"))
dx
#> Key: <id>
#>         id   cat        x   fcat
#>      <int> <int>    <num> <fctr>
#>   1:     1     1 6.173198    one
#>   2:     2     3 3.451851  three
#>   3:     3     2 4.505016    two
#>   4:     4     3 6.589504  three
#>   5:     5     2 1.835221    two
#>  ---                            
#> 196:   196     3 5.704497  three
#> 197:   197     1 4.854637    one
#> 198:   198     3 4.258349  three
#> 199:   199     3 4.017217  three
#> 200:   200     3 4.772752  three

# Second example:

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