robustbase: tolEllipsePlot – R documentation

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tolEllipsePlot

Tolerance Ellipse Plot

Description

Plots the 0.975 tolerance ellipse of the bivariate data set x. The ellipse is defined by those data points whose distance is equal to the squareroot of the 0.975 chisquare quantile with 2 degrees of freedom.

Usage

tolEllipsePlot(x, m.cov = covMcd(x), cutoff = NULL, id.n = NULL,
               classic = FALSE, tol = 1e-07,
               xlab = "", ylab = "",
               main = "Tolerance ellipse (97.5%)",
               txt.leg = c("robust", "classical"),
               col.leg = c("red", "blue"),
               lty.leg = c("solid","dashed"))

Arguments

`x`	a two dimensional matrix or data frame.
`m.cov`	an object similar to those of class `"mcd"`; however only its components `center` and `cov` will be used. If missing, the MCD will be computed (via `covMcd()`).
`cutoff`	numeric distance needed to flag data points outside the ellipse.
`id.n`	number of observations to be identified by a label. If not supplied, the number of observations with distance larger than `cutoff` is used.
`classic`	whether to plot the classical distances as well, `FALSE` by default.
`tol`	tolerance to be used for computing the inverse, see `solve`. Defaults to `1e-7`.
`xlab, ylab, main`	passed to `plot.default`.
`txt.leg, col.leg, lty.leg`	character vectors of length 2 for the legend, only used if `classic = TRUE`.

Author(s)

Peter Filzmoser, Valentin Todorov and Martin Maechler

Examples

data(hbk)
hbk.x <- data.matrix(hbk[, 1:3])
mcd <- covMcd(hbk.x)       # compute mcd in advance
## must be a 2-dimensional data set: take the first two columns :
tolEllipsePlot(hbk.x[,1:2])

## an "impressive" example:
data(telef)
tolEllipsePlot(telef, classic=TRUE)

robustbase

Basic Robust Statistics

v0.93-7

GPL (>= 2)

Authors

Martin Maechler [aut, cre] (<https://orcid.org/0000-0002-8685-9910>), Peter Rousseeuw [ctb] (Qn and Sn), Christophe Croux [ctb] (Qn and Sn), Valentin Todorov [aut] (most robust Cov), Andreas Ruckstuhl [aut] (nlrob, anova, glmrob), Matias Salibian-Barrera [aut] (lmrob orig.), Tobias Verbeke [ctb, fnd] (mc, adjbox), Manuel Koller [aut] (mc, lmrob, psi-func.), Eduardo L. T. Conceicao [aut] (MM-, tau-, CM-, and MTL- nlrob), Maria Anna di Palma [ctb] (initial version of Comedian)

Initial release

2021-01-04