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Population variance

Source: R/population_variances.R
pop_var.Rd

Divides by N rather than N - 1, which is what a schedule of potential outcomes calls for: the seven villages in Table 2.1 are the population, not a sample drawn from one. stats::var() divides by N - 1.

Usage

pop_var(x, na.rm = FALSE)

Arguments

x

a numeric vector

na.rm

logical. Should missing values be removed? When FALSE (the default) a single missing value makes the result NA, as in stats::var(). When TRUE missing values are dropped and the divisor is the number of values that remain.

Examples

x <- c(1, 2, 3, 4)
pop_var(x) # divides by n
#> [1] 1.25

# For comparision
var(x) # divides by n - 1
#> [1] 1.666667

pop_var(c(1, 2, NA, 4)) # NA
#> [1] NA
pop_var(c(1, 2, NA, 4), na.rm = TRUE) # divides by 3
#> [1] 1.555556