All pairs mean and sum of absolute differences

The functions compute the sum or mean of all pairwise absolute differences. This differs from stats::mad(), which computes the median absolute difference of each value from the median of all the values. See the ISIwithR package (and the textbook it accompanies) for examples using these functions in the context of simulation-based inference.

Usage

MAD(x, ..., data = NULL, groups = NULL, na.rm = getOption("na.rm", FALSE))

SAD(x, ..., data = NULL, groups = NULL, na.rm = getOption("na.rm", FALSE))

Arguments

x

a numeric vector or a formula.

...

additional arguments passed through to MAD_ or SAD_. If x is a formula, ... should include an argument named data if the intent is to interpret the formula in a data frame.

data

a data frame in which to evaluate formulas (or bare names). Note that the default is data = parent.frame(). This makes it convenient to use this function interactively by treating the working environment as if it were a data frame. But this may not be appropriate for programming uses. When programming, it is best to use an explicit data argument – ideally supplying a data frame that contains the variables mentioned.

groups

a grouping variable, typically a name of a variable in data

na.rm

a logical indicating whether NAs should be removed before calculating.

Value

the mean or sum of the absolute differences between each pair of values in c(x,...).

See also

mad(), MAD_()

Examples

SAD(1:3)
#> [1] 4
MAD(1:3)
#> [1] 1.333333
MAD(~eruptions, data = faithful)
#> [1] 171.5886