R: Leave-one-out cross-validation for a 'dudi'

loocv.dudi {ade4} | R Documentation

## Leave-one-out cross-validation for a `dudi`

### Description

Leave-one-out cross-validation to check the dispersion of row coordinates in a `dudi`.

### Usage

    ## S3 method for class 'dudi'
    loocv(x, progress = FALSE, ...)

### Arguments

`x` | the dudi of the `bca` on which cross-validation should be done
`progress` | logical to display a progress bar during computations (see the `progress` package)
`...` | further arguments passed to or from other methods

### Details

This function returns a list with two elements: `$XValCoord` and `$lsFac`, the cross-validated row coordinates and a factor to plot them. The analysis is redone after removing each row of the data table, one at a time. The coordinates of the missing row are computed by projection as supplementary element in the `dudi` space. This can be used to check the dispersion of the coordinates of one point and it's sensitivity to outliers.

### Value

a list with two elements: `$XValCoord` and `$lsFac` containing the cross-validated row coordinates and the factor to plot them using the `s.class` (see example).

### Author(s)

Jean Thioulouse

### See Also

suprow

### Examples

    data(meaudret)
    envpca <- dudi.pca(meaudret$env, scannf = FALSE, nf = 3)
    xvpca <- loocv(envpca)
    s.match(envpca$li, xvpca$XValCoord)

[Package ade4 version 1.7-16 Index]