compositions (version 1.40-2)

getdetectionlimit: Gets the detection limit stored in the data set

Description

The detection limit of those values below-detection-limit are stored as negative values in compositional dataset. This function extracts that information.

Usage

getDetectionlimit(x,dl=attr(x,"detectionlimit"))

Arguments

x

a data set

dl

a default to replace the information in the dataset

Value

a matrix in the same shape as x, with a positive value (the detection limit) where available, and NA in the other cells.

Details

For a proper treatment of truncated data it would be necessary to know the detection limit even for observed data. Unfortunately, there is no clear way to encode this information without annoying the user.

References

Boogaart, K.G. v.d., R. Tolosana-Delgado, M. Bren (2006) Concepts for handling of zeros and missing values in compositional data, in E. Pirard (ed.) (2006)Proceedings of the IAMG'2006 Annual Conference on "Quantitative Geology from multiple sources", September 2006, Liege, Belgium, S07-01, 4pages, ISBN 978-2-9600644-0-7, http://www.stat.boogaart.de/Publications/iamg06_s07_01.pdf

See Also

compositions.missings,zeroreplace

Examples

# NOT RUN {
x <- c(2,-0.5,4,3,-0.5,5,BDLvalue,MARvalue,MNARvalue)
getDetectionlimit(x)

# }