ellipses {compositions} | R Documentation

## Draw ellipses

### Description

Draws ellipses from a mean and a variance into a plot.

### Usage

              ellipses(mean,...)
              ## S3 method for class 'acomp':
              ellipses(mean,var,r=1,...,steps=360)
              ## S3 method for class 'rcomp':
              ellipses(mean,var,r=1,...,steps=360)
              ## S3 method for class 'aplus':
              ellipses(mean,var,r=1,...,steps=360)
              ## S3 method for class 'rplus':
              ellipses(mean,var,r=1,...,steps=360)
              ## S3 method for class 'rmult':
              ellipses(mean,var,r=1,...,steps=360)

### Arguments

`mean` | a dataset/vector of means or midpoints of the ellipses
`var` | a variance matrix or a set of variance matrices given by `var[i,,]`. The principal axis of the variance give the axis of the ellipses, whereas the square-root of the eigenvalues times r give the half-diameters of the ellipse.
`r` | a scaling of the half-diameters
`...` | further graphical parameters
`steps` | the number of discretisation points to draw the ellipses.

### Details

The ellipse drawn is given by the solutions of

(x-mean)^tvar^{-1}(x-mean)=r^2

in the respective geometry of the parameter space. Note that these ellipses can be added to panel plots (by means of orthogonal projections in the corresponding geometry).

### Author(s)

K.Gerald v.d. Boogaart http://www.stat.boogaart.de

### See Also

`plot.acomp`,

### Examples

    data(SimulatedAmounts)

    plot(acomp(sa.lognormals))
    tt<-acomp(sa.lognormals); ellipses(mean(tt),var(tt),r=2,col="red")
    tt<-rcomp(sa.lognormals); ellipses(mean(tt),var(tt),r=2,col="blue")

    plot(aplus(sa.lognormals[,1:2]))
    tt<-aplus(sa.lognormals[,1:2]); ellipses(mean(tt),var(tt),r=2,col="red")
    tt<-rplus(sa.lognormals[,1:2]); ellipses(mean(tt),var(tt),r=2,col="blue")

    plot(rplus(sa.lognormals[,1:2]))
    tt<-aplus(sa.lognormals[,1:2]); ellipses(mean(tt),var(tt),r=2,col="red")
    tt<-rplus(sa.lognormals[,1:2]); ellipses(mean(tt),var(tt),r=2,col="blue")
    tt<-rmult(sa.lognormals[,1:2]); ellipses(mean(tt),var(tt),r=2,col="green")

[Package compositions version 0.91-6 Index]