Outliers

Identify outliers using modified Z-score

outliers(x, s = 1.4826)

Arguments

x	A numeric vector
s	Scaling factor for mad statistic

Value

value for the modified Z-score

References

Iglewicz, B. & D.C. Hoaglin (1993) How to Detect and Handle Outliers, American Society for Quality Control, Milwaukee, WI.

Author

Jeffrey S. Evans <jeffrey_evans@tnc.org>

Examples

 # Create data with 3 outliers
    x <- seq(0.1, 5, length=100) 
    x[98:100] <- c(100, 55, 250)
 
 # Calculate Z score
     Z <- outliers(x) 
 
 # Show number of extreme outliers using Z-score
     length(Z[Z > 9.9])
#> [1] 3
 
 # Remove extreme outliers 
     x <- x[-which(Z > 9.9)]