R: Siegel's Exact Fit Example Data

SiegelsEx {robustbase} | R Documentation

## Siegel's Exact Fit Example Data

### Description

A small counterexample data set devised by Andrew Siegel. Six (out of nine) data points lie on the line y = 0 such that some robust regression estimators exhibit the “exact fit” property.

### Usage

    data(SiegelsEx, package="robustbase")

### Format

A data frame with 9 observations on the following 2 variables.

`x`

  a numeric vector

`y`

  a numeric vector

### Source

Emerson and Hoaglin (1983, p.139)

### References

Peter J. Rousseeuw and Annick M. Leroy (1987) Robust Regression and Outlier Detection Wiley, p.60–61

### Examples

    data(SiegelsEx)
    plot(SiegelsEx, main = "Siegel's example for 'exact fit'")
    abline(          lm(y ~ x, data = SiegelsEx))
    abline(MASS::lqs(y ~ x, data = SiegelsEx, method = "lms"), col = 2)
    legend("topright", leg = c("lm", "LMS"), col=1:2, lwd=1, inset = 1/20)

[Package robustbase version 0.93-9 Index]