convert variables with unique values along the data set to attributes and then remove those unique variables

Usage

uniq_vars_to_attr(x, exclude_vars = NULL)

Arguments

x: a data.frame
exclude_vars: variables to be excluded from turning to attributes (default NULL)

Value

data.frame with multiple-value variables only and single-value variables as attributes

Examples

dt <- data.table::data.table(a = 1, b = 1:10, c = 5)
out <- uniq_vars_to_attr(dt)
out[]
#>         b
#>     <int>
#>  1:     1
#>  2:     2
#>  3:     3
#>  4:     4
#>  5:     5
#>  6:     6
#>  7:     7
#>  8:     8
#>  9:     9
#> 10:    10
attr(out, "a")
#> [1] 1
attr(out, "c")
#> [1] 5

# Exclude `a` from being added as attribute
out <- uniq_vars_to_attr(dt, "a")
out[]
#>         a     b
#>     <num> <int>
#>  1:     1     1
#>  2:     1     2
#>  3:     1     3
#>  4:     1     4
#>  5:     1     5
#>  6:     1     6
#>  7:     1     7
#>  8:     1     8
#>  9:     1     9
#> 10:     1    10

# var `a` is not included as part of the attributes
attr(out, "a")
#> [1] 1

# Var `c` is
attr(out, "c")
#> [1] 5