Description Usage Arguments Details Value Author(s) References See Also Examples

A function that performs PCA using the robust estimators "S-estimator","MCD" and "MVE".

1 2 3 4 5 |

`x` |
a matrix. Contains the data to perform PCA on. |

`robust` |
The robust estimator to use. One of |

`nsamp` |
The number of subsamples that the robust estimator should use. This defaults to 10 times the number of rows in the matrix. |

`...` |
Further arguments that can be passed to the robust estimator |

The calculation is done by a singular value decomposition of the
robust centered and scaled data matrix, not by using
`eigen`

on the covariance matrix. This
is generally the preferred method for numerical accuracy. The
`print`

method for the these objects prints the results in a nice
format and the `plot`

method produces a scree plot. The
scree plot can be used to determine the number k of principal components preserved in the
analysis, looking for the “elbow” or
the first important bend in the line. A biplot can also be generated
to represent the values of the first two principal components (PCs) and the
contribution of each variable to these components in the same plot (see Supplementary
Material of Cohen Freue et al. (2007)).

`prcomp.robust`

returns a list with class `"prcomp"`

containing the following components:

`sdev` |
the standard deviations of the principal components (i.e.,
the square roots of the eigenvalues of the covariance
matrix calculated using the |

`rotation` |
the matrix of variable loadings (i.e., a matrix whose
columns contain the eigenvectors). The function |

`x` |
the value of the rotated data (the centered and scaled) data multiplied by the |

Justin Harrington harringt@stat.ubc.ca and Gabriela V. Cohen Freue gcohen@stat.ubc.ca.

Cohen Freue, G. V. and Hollander, Z. and Shen, E. and Zamar, R. H. and Balshaw,
R. and Scherer, A. and McManus, B. and Keown, P. and McMaster, W. R. and Ng,
R. T. (2007) ‘MDQC: A New Quality Assessment Method for Microarrays
Based on Quality Control Reports’. *Bioinformatics* **23**, 3162 – 3169.

1 2 3 4 5 6 7 8 9 10 11 12 13 |

```
Loading required package: cluster
Loading required package: MASS
```

Embedding an R snippet on your website

Add the following code to your website.

For more information on customizing the embed code, read Embedding Snippets.