stats (version 3.1.1)

sd: Standard Deviation

Description

This function computes the standard deviation of the values in x. If na.rm is TRUE then missing values are removed before computation proceeds.

Usage

sd(x, na.rm = FALSE)

Arguments

x

a numeric vector or an R object which is coercible to one by as.vector(x, "numeric").

na.rm

logical. Should missing values be removed?

Details

Like var this uses denominator $n - 1$.

The standard deviation of a zero-length vector (after removal of NAs if na.rm = TRUE) is not defined and gives an error. The standard deviation of a length-one vector is NA.

See Also

var for its square, and mad, the most robust alternative.

Examples

sd(1:2) ^ 2