R: Compute the Volume (of an Ellipsoid)

volume.ellipsoid {cluster} | R Documentation

## Compute the Volume (of an Ellipsoid)

### Description

Compute the volume of geometric R object. This is a generic function and has a method for `ellipsoid` objects (typically resulting from `ellipsoidhull()`.

### Usage

    volume(object, ...)
    ## S3 method for class 'ellipsoid'
    volume(object, log = FALSE, ...)

### Arguments

`object` | an R object the volume of which is wanted; for the `ellipsoid` method, an object of that class (see `ellipsoidhull` or the example below).
`log` | `logical` indicating if the volume should be returned in log scale. Maybe needed in largish dimensions.
`...` | potential further arguments of methods, e.g. `log`.

### Value

a number, the volume V (or \log(V) if `log = TRUE`) of the given `object`.

### Author(s)

Martin Maechler (2002, extracting from former `clusplot` code); Keefe Murphy (2019) provided code for dimensions d > 2.

### See Also

`ellipsoidhull` for spanning ellipsoid computation.

### Examples

    ## example(ellipsoidhull) # which defines 'ellipsoid' object <namefoo>

    myEl <- structure(list(cov = rbind(c(3,1),1:2), loc = c(0,0), d2 = 10),
                       class = "ellipsoid")
    volume(myEl)# i.e. "area" here (d = 2)
    myEl # also mentions the "volume"

    set.seed(1)
    d5 <- matrix(rt(500, df=3), 100,5)
    e5 <- ellipsoidhull(d5)

[Package cluster version 2.1.0 Index]