genefu (version 2.4.2)

tbrm: 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.

Value

• A numeric mean.

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.

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))