tbrm {genefu} | R Documentation

## Function to compute Tukey's Biweight Robust Mean

### Description

Computation of Tukey's Biweight Robust Mean, a robust average that is unaffected by outliers.

### Usage

    tbrm(x, C = 9)

### Arguments

`x` | a numeric vector
`C` | a constant. `C` is preassigned a value of 9 according to the Cook reference below but other values are possible.

### Details

This is a one step computation that follows the Affy whitepaper below see page 22. This function is called by `chron` to calculate a robust mean. `C` determines the point at which outliers are given a weight of 0 and therefore do not contribute to the calculation of the mean. C=9 sets values roughly +/-6 standard deviations to 0. C=6 is also used in tree-ring chronology development. Cook and Kairiukstis (1990) have further details.

Retrieved from `tbrm`.

### Value

A numeric mean.

### Author(s)

Andy Bunn

### References

Statistical Algorithms Description Document, 2002, Affymetrix. p22.

Cook, E. R. and Kairiukstis, L.A. (1990) Methods of Dendrochronology: Applications in the Environmental Sciences. ISBN-13: 978-0792305866.

Mosteller, F. and Tukey, J. W. (1977) Data Analysis and Regression: a second course in statistics. Addison-Wesley. ISBN-13: 978-0201048544.

### See Also

`chron`

### Examples

    tbrm(rnorm(100))

[Package genefu version 2.22.1 Index]