Gini impurity (Geron Ch 6, morie.fn hmgini)

G = 1 - sum_k p_k^2, with the K-class ceiling 1 - 1/K reported so a value can be read against its own maximum.

Usage

morie_geron_gini_impurity(y)

Arguments

y

Vector of labels.

Value

List with gini, proportions, classes, counts, n_classes, max_possible, estimate, n.

Examples

V <- c(1, 2, 3, 4, 5, 6, 7, 8)
morie_geron_gini_impurity(V)
#> $gini
#> [1] 0.875
#> 
#> $proportions
#> [1] 0.125 0.125 0.125 0.125 0.125 0.125 0.125 0.125
#> 
#> $classes
#> [1] 1 2 3 4 5 6 7 8
#> 
#> $counts
#> [1] 1 1 1 1 1 1 1 1
#> 
#> $n_classes
#> [1] 8
#> 
#> $max_possible
#> [1] 0.875
#> 
#> $estimate
#> [1] 0.875
#> 
#> $n
#> [1] 8
#> 
#> $method
#> [1] "Gini impurity G = 1 - sum_k p_k^2"
#>