gsi.produceV: Create a matrix of logcontrasts and name prefix

In gmGeostats: Geostatistics for Compositional Analysis

Create a matrix of logcontrasts and name prefix

Description

Given a representation specification for compositions, this function creates the matrix of logcontrasts and provides a suitable prefix name for naming variables.

Usage

gsi.produceV(
  V = NULL,
  D = nrow(V),
  orignames = rownames(V),
  giveInv = FALSE,
  prefix = NULL
)

Arguments

V	either a matrix of logcontrasts or, most commonly, one of "clr", "ilr" or "alr"
D	the number of components of the composition represented
orignames	the names of the components
giveInv	logical, is the inverse logcontrast matrix desired?
prefix	the desired prefix name, if this is wished to be forced.

Value

A list with at least two elements

1. V containing the final matrix of logcontrasts

2. prefix containing the final prefix for names of transformed variables

3. W eventually, the (transposed, generalised) inverse of V, if giveInv=TRUE

Examples

gsi.produceV("alr", D=3)
gsi.produceV("ilr", D=3, orignames = c("Ca", "K", "Na"))
gsi.produceV("alr", D=3, orignames = c("Ca", "K", "Na"), giveInv = TRUE)

gmGeostats documentation built on Aug. 21, 2025, 5:43 p.m.