Create a dummy matrix from the elements in a list

Create a dummy matrix based on the elements of a list. Each column in the produced matrix is a dummy indicator.

list_to_dummy(alist)

Arguments

alist

a list of vectors

Value

A matrix of dummy variables

Author

Gaston Sanchez

Examples

# let's say you have a list like this
num_list = list(1:3, 4:5, 6:9)

# get dummy matrix
list_to_dummy(num_list)
#>       [,1] [,2] [,3]
#>  [1,]    1    0    0
#>  [2,]    1    0    0
#>  [3,]    1    0    0
#>  [4,]    0    1    0
#>  [5,]    0    1    0
#>  [6,]    0    0    1
#>  [7,]    0    0    1
#>  [8,]    0    0    1
#>  [9,]    0    0    1

# try with a list of strings
str_list = list(c("a","b","c"), c("d", "e"), c("f","g","h"))
list_to_dummy(str_list)
#>      [,1] [,2] [,3]
#> [1,]    1    0    0
#> [2,]    1    0    0
#> [3,]    1    0    0
#> [4,]    0    1    0
#> [5,]    0    1    0
#> [6,]    0    0    1
#> [7,]    0    0    1
#> [8,]    0    0    1