indicator variables

converts a single categorical variable into indicator variables

imat(x, allcat = TRUE)

Arguments

x	A factor variable.
allcat	Whether or not to keep all categories or leave the last one out.

Value

matrix

Examples

require(MASS)
imat(housing$Type)
#>       Tower Apartment Atrium Terrace
#>  [1,]     1         0      0       0
#>  [2,]     1         0      0       0
#>  [3,]     1         0      0       0
#>  [4,]     1         0      0       0
#>  [5,]     1         0      0       0
#>  [6,]     1         0      0       0
#>  [7,]     1         0      0       0
#>  [8,]     1         0      0       0
#>  [9,]     1         0      0       0
#> [10,]     0         1      0       0
#> [11,]     0         1      0       0
#> [12,]     0         1      0       0
#> [13,]     0         1      0       0
#> [14,]     0         1      0       0
#> [15,]     0         1      0       0
#> [16,]     0         1      0       0
#> [17,]     0         1      0       0
#> [18,]     0         1      0       0
#> [19,]     0         0      1       0
#> [20,]     0         0      1       0
#> [21,]     0         0      1       0
#> [22,]     0         0      1       0
#> [23,]     0         0      1       0
#> [24,]     0         0      1       0
#> [25,]     0         0      1       0
#> [26,]     0         0      1       0
#> [27,]     0         0      1       0
#> [28,]     0         0      0       1
#> [29,]     0         0      0       1
#> [30,]     0         0      0       1
#> [31,]     0         0      0       1
#> [32,]     0         0      0       1
#> [33,]     0         0      0       1
#> [34,]     0         0      0       1
#> [35,]     0         0      0       1
#> [36,]     0         0      0       1
#> [37,]     1         0      0       0
#> [38,]     1         0      0       0
#> [39,]     1         0      0       0
#> [40,]     1         0      0       0
#> [41,]     1         0      0       0
#> [42,]     1         0      0       0
#> [43,]     1         0      0       0
#> [44,]     1         0      0       0
#> [45,]     1         0      0       0
#> [46,]     0         1      0       0
#> [47,]     0         1      0       0
#> [48,]     0         1      0       0
#> [49,]     0         1      0       0
#> [50,]     0         1      0       0
#> [51,]     0         1      0       0
#> [52,]     0         1      0       0
#> [53,]     0         1      0       0
#> [54,]     0         1      0       0
#> [55,]     0         0      1       0
#> [56,]     0         0      1       0
#> [57,]     0         0      1       0
#> [58,]     0         0      1       0
#> [59,]     0         0      1       0
#> [60,]     0         0      1       0
#> [61,]     0         0      1       0
#> [62,]     0         0      1       0
#> [63,]     0         0      1       0
#> [64,]     0         0      0       1
#> [65,]     0         0      0       1
#> [66,]     0         0      0       1
#> [67,]     0         0      0       1
#> [68,]     0         0      0       1
#> [69,]     0         0      0       1
#> [70,]     0         0      0       1
#> [71,]     0         0      0       1
#> [72,]     0         0      0       1