RSlo: Rosner RST Test Adjusted for Low Outliers

Description Usage Arguments Value Note Author(s) Source References See Also Examples

Description

The Rosner (1975) method or the essence of the method, given the order statistics x_{[1:n]} ≤ x_{[2:n]} ≤ \cdots ≤ x_{[(n-1):n]} ≤ x_{[n:n]}, is the statistic:

RS_r = \frac{ x_{[r:n]} - \mathrm{mean}\{x_{[(r+1)\rightarrow(n-r):n]}\} } {√{\mathrm{var}\{x_{[(r+1)\rightarrow(n-r):n]}\}}}\mbox{,}

Usage

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RSlo(x, r, n=length(x))

Arguments

x

The data values and note that base-10 logarithms of these are not computed internally;

r

The number of truncated observations; and

n

The number of observations.

Value

The value for RS_r.

Note

Regarding n=length(x), it is not clear that TAC intended n to be not equal to the sample size. TAC chose to not determine the length of x internally to the function but to have it available as an argument. Also MGBTcohn2011 and BLlo were similarly designed.

Author(s)

W.H. Asquith consulting T.A. Cohn sources

Source

LowOutliers_jfe(R).txt and LowOutliers_wha(R).txt—Named RST

References

Cohn, T.A., 2013–2016, Personal communication of original R source code: U.S. Geological Survey, Reston, Va.

Rosner, Bernard, 1975, On the detection of many outliers: Technometrics, v. 17, no. 2, pp. 221–227.

See Also

MGBTcohn2011, BLlo

Examples

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## Not run: 
testMGBvsN3 <- function(n=100, maxr=n/2, nrep=10000) { # TAC named function
   for(r in 1:maxr) {
      set.seed(123457)
      res1 <- replicate(nrep, { x <- sort(rnorm(n))
                 c(MGBTcohn2011(x,r),BLlo(x,r),RSlo(x,r)) })
      r1 <- rank(res1[1,]); r2 <- rank(res1[2,]); r3 <- rank(res1[3,])
      v <- quantile(r1,.1); h <- quantile(r2,.1)
      plot(r1,r2)
      abline(v=v, col=2); abline(h=h, col=2)
      message(' BLlo ',r, " ", cor(r1,r2), " ", mean((r1 <= v) & (r2 <= h)))
      v <- quantile(r1,.1); h <- quantile(r2,.1)
      plot(r1,r3)
      abline(v=v, col=2); abline(h=h, col=2)
      message('RSTlo ',r, " ", cor(r1,r3), " ", mean((r1 <= v) & (r3 <= h)))
   }
}
testMGBvsN3() #
## End(Not run)

wasquith-usgs/MGBT documentation built on Aug. 6, 2019, 4:57 p.m.