R: Identify Extreme Values in 3D

labelExtremes3d {ChemoSpec} | R Documentation

## Identify Extreme Values in 3D

### Description

A utility function to identify the extreme values in a 3D plot data set, presumably so that they can be labeled. Algorithm is similar to `labelExtremes`, except that `labelExtremes3d` does not do the plotting (because the results are used by functions that use different plotting paradigms). An internal function, not generally called by the user.

### Usage

    labelExtremes3d(data, names, tol)

### Arguments

`data` | A matrix of 3 columns containing x, y and z values for the labels, with rows corresponding to sample names.
`names` | A character vector of sample names; must have length equal to `nrow(data)`.
`tol` | A number describing the fraction of points to be labeled. `tol = 1.0` labels all the points; `tol = 0.05` labels approximately the most extreme 5 percent. Note that this is simply based upon quantiles, assumes that x, y and z are each normally distributed, and treats x, y and yz separately. Thus, this is not a formal treatment of outliers, just a means of labeling points. Note too that while this function could deal with groups separately, the way it is called by `plotScoresRGL` lumps all groups together.

### Value

A data frame containing the x, y and z coordinates, along with the corresponding labels.

### Author(s)

Bryan A. Hanson, DePauw University.

### References

https://github.com/bryanhanson/ChemoSpec

[Package ChemoSpec version 4.4.97 Index]