LR.VAR: Total logratio variance
In easyCODA: Compositional Data Analysis in Practice

Description Usage Arguments Details Value Author(s) References See Also Examples

Computation of total (weighted)logratio variance.

1	LR.VAR(LRdata, row.wt = NA, weight=TRUE, vars=FALSE)

`LRdata`	Matrix of logratios, either a vector or preferably the logratio object resulting from one of the functions ALR, CLR, PLR or LR
`row.wt`	Optional set of row weights (default: equal weights)
`weight`	Logical indicating if varying weights are returned(default:`TRUE`). If `FALSE`, unweighted (equal) weights are returned. Alternatively a set of positive weights can be specified.
`vars`	If `TRUE`, output individual variances as well (default `FALSE`)

The function LR.VAR computes the sum of the logratio variances provided as input, using the weights in the logratio data object.

`LRtotvar`	The total logratio variance
`LRvars`	(optional, if vars=TRUE, the individual logratio variances composing the total)

Michael Greenacre

Aitchison, J. (1986), The Statistical Analysis of Compositional Data, Chapman & Hall.
Greenacre, M. (2018), Compositional Data Analysis in Practice, Chapman & Hall / CRC Press.

LR, ALR, invALR, CLR, invCLR

data(cups)
# These give identical total logratio variances (weighted, by default)
LR.VAR(CLR(cups))
LR.VAR(LR(cups))
# Summing over all sets of ALRs gives twice the variance
totvar <- 0
for(j in 1:ncol(cups)) totvar <- totvar + LR.VAR(ALR(cups, denom=j))
totvar/2

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