R: Conversion Between PCA Classes

q2rPCA {ChemoSpec} | R Documentation

## Conversion Between PCA Classes

### Description

Utility to convert objects of S3 class `prcomp` (Q-mode PCA) to objects of S3 class `princomp` (R-mode PCA) or vice-versa. An internal function, not generally called by the user.

### Usage

    q2rPCA(x)

### Arguments

`x` | An object of either class `prcomp` or class `princomp`. It will be converted to a form that can be used by functions expecting either class.

### Details

In the conversion, the necessary list elements are added; the old elements are not deleted (and user added list elements are not affected). To indicate this, the class attribute is updated to include class `conPCA`. The new object can then be used by functions expecting either class prcomp or princomp. For details of the structure of `prcomp` or `princomp`, see their respective help pages.

### Value

A list of class `conPCA`. Note that the order of the elements will vary depending upon the direction of conversion.

`loadings` | The loadings from `princomp`, or a copy of the rotations from `prcomp`.
`scores` | The scores from `princomp`, or a copy of the x values from `prcomp`.
`call` | The call. Objects of class `prcomp` do not store the original call, so a place holder is used. Otherwise the unchanged call from `princomp`.
`n.obs` | The number of observations from `princomp`, or computed from the 1st dimension of x in `prcomp`.
`class` | `conPCA` is pre-pended to the existing class.
`sdev` | Unchanged from original.
`center` | Unchanged from original.
`scale` | Unchanged from original.

### Author(s)

Bryan A. Hanson, DePauw University.

### References

https://github.com/bryanhanson/ChemoSpec

### See Also

`prcomp`, `princomp`

[Package ChemoSpec version 4.4.97 Index]