Computes standard error of the mean.

Computes the standard error of the mean (i.e., standard deviation divided by the square root of the sample size).

Usage

se(x, na.rm = TRUE)

Arguments

x

A numeric vector.

na.rm

A logical that indicates whether missing values should be removed before computing the standard error.

Value

A single numeric that is the standard error of the mean of x.

Details

The standard error of the value in vector x is simply the standard deviation of x divided by the square root of the number of valid items in x

See also

See se in sciplot for similar functionality.

Author

Derek H. Ogle, DerekOgle51@gmail.com

Examples

# example vector
x <- 1:20
se(x)
#> [1] 1.322876
sd(x)/sqrt(length(x))   ## matches
#> [1] 1.322876

# all return NA if missing values are not removed
x2 <- c(x,NA)
sd(x2)/sqrt(length(x2))
#> [1] NA

# Better if missing values are removed
se(x2)              ## Default behavior
#> [1] 1.322876
sd(x2,na.rm=TRUE)/sqrt(length(x2[complete.cases(x2)]))  ## Matches
#> [1] 1.322876
se(x2,na.rm=FALSE)  ## Result from not removing NAs
#> [1] NA