Create dummy variables from a factor or integer variable

genDummy(dtName, varname, sep = ".", replace = FALSE)

Arguments

dtName

Data table with column

varname

Name of factor

sep

Character to be used in creating new name for dummy fields. Valid characters include all letters and "_". Will default to ".". If an invalid character is provided, it will be replaced by default.

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 4.479586
#>   2:   2   1 5.234123
#>   3:   3   2 4.100791
#>   4:   4   3 6.225520
#>   5:   5   2 6.188477
#>  ---                 
#> 196: 196   3 6.966713
#> 197: 197   3 4.144871
#> 198: 198   3 6.773981
#> 199: 199   2 2.501137
#> 200: 200   3 3.028021

dx <- genFactor(dx, "cat", labels = c("one", "two", "three"), replace = TRUE)
dx <- genDummy(dx, varname = "fcat", sep = "_")

dx
#>       id        x  fcat fcat_one fcat_two fcat_three
#>   1:   1 4.479586 three        0        0          1
#>   2:   2 5.234123   one        1        0          0
#>   3:   3 4.100791   two        0        1          0
#>   4:   4 6.225520 three        0        0          1
#>   5:   5 6.188477   two        0        1          0
#>  ---                                                
#> 196: 196 6.966713 three        0        0          1
#> 197: 197 4.144871 three        0        0          1
#> 198: 198 6.773981 three        0        0          1
#> 199: 199 2.501137   two        0        1          0
#> 200: 200 3.028021 three        0        0          1

# Second example:

dx <- genData(15)
dx <- trtAssign(dtName = dx, 3, grpName = "arm")
dx <- genDummy(dx, varname = "arm")
dx
#>     id arm arm.1 arm.2 arm.3
#>  1:  1   2     0     1     0
#>  2:  2   3     0     0     1
#>  3:  3   1     1     0     0
#>  4:  4   1     1     0     0
#>  5:  5   2     0     1     0
#>  6:  6   1     1     0     0
#>  7:  7   2     0     1     0
#>  8:  8   2     0     1     0
#>  9:  9   2     0     1     0
#> 10: 10   3     0     0     1
#> 11: 11   3     0     0     1
#> 12: 12   3     0     0     1
#> 13: 13   1     1     0     0
#> 14: 14   1     1     0     0
#> 15: 15   3     0     0     1