Gini-Simpson Index

Gini-Simpson Index

Usage

concstats_simpson(x, na.rm = TRUE, digits = NULL)

Arguments

x

A non-negative numeric vector.

na.rm

A logical vector that indicates whether NA values should be excluded or not. Must be either TRUE or FALSE. The default is TRUE. If set to FALSE the computation yields a message if the vector contains NA values. NAs will be removed for further computations.

digits

An optional value for digits. Specifies the minimum number of significant digits to be printed in values. The default is NULL and will use base R print option.

Value

A single numeric value in decimal form.

Details

concstats_simpson is the Gini-Simpson index, also known as the Gini impurity (Gini's diversity index) in Machine Learning, Gibbs-Martin index or Blau index in sociology and management studies. This index ranges from {0, 1}.

References

Simpson, E. H. (1949). "Measurement of Diversity", Nature, 163, 688.

Jost, L. (2006). "Entropy and Diversity". Oikos, 113(2), 363-375.

See also

Other Concentration and inequality measures: concstats_all_inequ(), concstats_entropy(), concstats_gini(), concstats_grs(), concstats_inequ(), concstats_palma()

Examples

# a vector of market shares
x <- c(0.4, 0.2, 0.25, 0.1, 0.05)
concstats_simpson(x)
#> [1] 0.725

concstats_simpson(x, digits = 2)
#> [1] 0.72

# a vector with NA values
x <- c(0.4, 0.2, 0.25, 0.1, 0.05, NA)
concstats_simpson(x, na.rm = TRUE)
#> `x` has NA values. NAs have been removed for computation.
#> [1] 0.725