clo {compositions}R Documentation

Closure of a composition

Description

Closes compositions to sum up to one (or an optional total), by dividing each part by the sum.

Usage

          clo( X, parts=1:NCOL(oneOrDataset(X)),total=1)
          

Arguments

X composition or dataset of compositions
parts vector containing the indices xor names of the columns to be used
total the total amount to which the compositions should be closed; either a single number, or a numeric vector of length gsi.getN(X) specifying a different total for each compositional vector in the dataset.

Details

The closure operation is given by

clo(x) := ( x_i / sum(x_j))

clo makes a composition without assigning one of the compositional classes acomp or rcomp. Note that after computing the closed-to-one version, obtaining a version closed to any other value is done by simple multiplication.

Value

a composition or a datamatrix of compositions without compositional class. The individual compositions are forced to sum to 1 (or to the optionally-specified total). The result should have the same shape as the input (vector, row, matrix).

Note

clo can be used to unclass compositions.

References

Aitchison, J. (1986) The Statistical Analysis of Compositional Data Monographs on Statistics and Applied Probability. Chapman & Hall Ltd., London (UK). 416p.

See Also

clr,acomp,rcomp

Examples

(tmp <- clo(c(1,2,3)))
clo(tmp,total=100)
data(Hydrochem)
cdata <- Hydrochem[,6:19]
plot( clo(Hydrochem,8:9) ) # Giving points on a line 


[Package compositions version 0.9-10 Index]