R/detect_out.R

In NRM-MOC/MoCiS: Monitoring of Contaminants in Sweden

##' Marks suspected outliers in a series
##'
##' Uses the methodology described in \ldots to check for suspected outliers.
##' @title detect_out
##' @param fit An \code{lm} fit.
##' @param alpha Cutoff for declaring a point an outlier, defaults to 0.05.
##' @return A vector with 0 and 1 where 1 denotes the suspected outlier.
##' @author Erik Lampa
##' @importFrom MASS studres
##' @export
detect_out <- function(fit, alpha) {
    ## Tests for outliers in the series
    
    r <- studres(fit)
    outs <- sapply(1:length(r), function(i) {
        tcrit <- qt(alpha, fit$df.residual)
        ifelse(-abs(r[i]) < tcrit, 1, 0)
    })
    outs
}