plotShape: Pairwise Scatterplot Matrix of Shape Matrices

Description

Function for visual comparisons for up to three shape matrices.

Usage

plotShape(est1, est2 = NULL, est3 = NULL, X = NULL, alim = NULL, 
          color.ell = 2:4, color.points = grey(0.5), 
          lty.ell = rep(1, 3), pch.ell = rep(16, 3), 
          lwd.ell = rep(1, 3), cex.ell = rep(1, 3),  
          pch.points = 1, level = 0.5, npoints = 100, 
          x.legend, y.legend, cex.legend = 1, pty = "s", gap = 1, 
          oma.bottom, labels, cex.labels = 2, main, ...)

Arguments

est1

The shape matrix of interest. A list with the components location, scatter and est.name.

est2

An optional additional shape matrix. A list with the components location, scatter and est.name.

est3

An optional additional shape matrix. A list with the components location, scatter and est.name.

a numeric data frame or matrix. Optional data points on which the estimates could have been based.

alim

can be NULL, both or ellipses. Specifies when the plotting regions are computed if only the size of the ellipses are to be considered or also the range of the data points. If NULL it cho

color.ell

vector of length 3 that gives the colors for the corresponding estimates 'est1', 'est2' and 'est3'.

color.points

the color of the data points.

lty.ell

line types of the confidence ellipsoids.

pch.ell

plotting symbols for the location estimates, the centers of the confidence ellipsoids.

lwd.ell

line width values of the confidence ellipsoids.

cex.ell

cex values for the location estimates, the centers of the confidence ellipsoids.

pch.points

plotting symbol for the data points X.

level

The proportion of the data points that should be inside the ellipses. If there is no data the value for t in the function ellipse.

npoints

the number of points used to approximate each ellipsoid.

x.legend

vertical position of the legend. By default tries to find for 2 to 4 dimensional data a good location. If NULL no legend is drawn.

y.legend

horicontal position of the legend. By default tries to find for 2 to 4 dimensional data a good location. If NULL no legend is drawn.

cex.legend

cex for the legend.

pty

pty value for the individual plots of the scatter matrix. Default is "s".

gap

distance between subplots, in margin lines.

oma.bottom

oma value of the bottom.

labels

optional labels for the diagonals.

cex.labels

cex for the labels. Default is 2.

main

optional title of the plot.

...

further arguments passed to or from other methods.

Value

A scatter plot matrix.

Details

All scatter matrices are standardized to have determinant 1. If X is given, the Mahalanobis distances based on the location and shape estimates are computed, and t in the function ellipse is the level quantile of the Mahalanobis distances. If no X is provided t equals level. The location of the legend is currently problematic and it is recommended that the user should provide the coordinates for the legend.

Examples

Run this code

X <- rmvt(100, diag(3), df=3)

EST1 <- list(location=colMeans(X), scatter=cov(X), est.name="COV")
HR <- HR.Mest(X)
EST2 <- list(location=HR$center, scatter=HR$scatter, est.name="Tyler")
plotShape(EST1,EST2, X=X)