IQR {stats}R Documentation

The Interquartile Range

Description

computes interquartile range of the x values.

Usage

IQR(x, na.rm = FALSE)

Arguments

x a numeric vector.
na.rm logical. Should missing values be removed?

Details

Note that this function computes the quartiles using the quantile function rather than following Tukey's recommendations, i.e., IQR(x) = quantile(x,3/4) - quantile(x,1/4).

For normally N(m,1) distributed X, the expected value of IQR(X) is 2*qnorm(3/4) = 1.3490, i.e., for a normal-consistent estimate of the standard deviation, use IQR(x) / 1.349.

References

Tukey, J. W. (1977). Exploratory Data Analysis. Reading: Addison-Wesley.

See Also

fivenum, mad which is more robust, range, quantile.

Examples

IQR(rivers)

[Package stats version 2.1.0 Index]