aDist {robCompositions} | R Documentation |
Computes the Aitchison distance between two observations or between two data sets.
aDist(x, y)
x |
a vector, matrix or data.frame |
y |
a vector, matrix or data.frame with equal dimension as x |
This distance measure accounts for the relative scale property of the
Aitchison distance. It measures the distance between two compositions if x
and y
are vectors and evaluate sum of the distances between x
and y
for each row of x
and y
if
x
and y
are matrices or data frames.
It is not designed to apply it on one matrix, such as function ‘acomp()’ in package ‘compositions’, but it is designed to compare different matrices.
The underlying code is written in C and allows a fast computation also for large data sets.
The Aitchison distance between two compositions or between two data sets.
Matthias Templ
Aitchison, J. (1986) The Statistical Analysis of Compositional Data Monographs on Statistics and Applied Probability. Chapman and Hall Ltd., London (UK). 416p.
Aitchison, J. and Barcelo-Vidal, C. and Martin-Fernandez, J.A. and Pawlowsky-Glahn, V. (2000) Logratio analysis and compositional distance. Mathematical Geology, 32, 271-275.
Hron, K. and Templ, M. and Filzmoser, P. (2010) Imputation of missing values for compositional data using classical and robust methods Computational Statistics and Data Analysis, In Press, Corrected Proof, ISSN: 0167-9473, DOI:10.1016/j.csda.2009.11.023
data(expenditures) x <- xOrig <- expenditures ## Aitchison distance between the first 2 observations: aDist(x[,1], x[,2]) ## set some missing values: x[1,3] <- x[3,5] <- x[2,4] <- x[5,3] <- x[8,3] <- NA ## impute them: xImp <- impCoda(x, method="ltsReg")$xImp ## calculate the relative Aitchsion distance between xOrig and xImp: aDist(xOrig, xImp)