Detect outliers using MAD (Median Absolute Deviation)

Usage

is_outlier(
  x,
  nmads = 2.5,
  constant = 1.4826,
  type = c("both", "lower", "higher")
)

Arguments

x: Numeric vector.
nmads: Number of median absolute deviations (MADs) from the median to define the boundaries for outliers. Default is 2.5.
constant: Constant factor to convert the MAD to a standard deviation. Default is 1.4826, which is consistent with the MAD of a normal distribution.
type: Type of outliers to detect. Available options are "both", "lower", or "higher". If type is "both", it detects both lower and higher outliers. If type is "lower", it detects only lower outliers. If type is "higher", it detects only higher outliers.

Value

Numeric vector of indices indicating the positions of outliers in x.

Examples

x <- c(1, 2, 3, 4, 5, 100)
is_outlier(x) # returns 6
#> [1] 6

x <- c(3, 4, 5, NA, 6, 7)
is_outlier(x, nmads = 1.5, type = "lower") # returns 4
#> [1] 4

x <- c(10, 20, NA, 15, 35)
is_outlier(x, nmads = 2, type = "higher") # returns 3, 5
#> [1] 3 5