gamma2sigma {asreml}R Documentation

Transforms variance components and AI matrix from gamma to sigma scale

Description

Some of the functions (summary.asreml and vpredict) require the components and the inverse of the average information (AI) matrix to be in sigma scale. If the model is in gamma, it has to be transformed This function can be used for that purpose.

Usage

gamma2sigma(
  object,
  where.sigma2 = attr(is.gamma(object), "where.sigma2"),
  what = c("varcomp", "ai"),
  ...
)

Arguments

object

An asreml object.

where.sigma2

A numeric value indicating the index of the sigma2 component in the vparameters object of the list object of class asreml (default = attr(is.gamma(object), "where.sigma2")).

what

A character vector indicating which object to obtain. Options are varcomp (the variance components) and ai (the inverse of the average information matrix) (default = (c("varcomp", "ai"))).

...

Additional arguments to asreml.options.

Value

A list with variance components (if requested; varcomp) and the inverse of the AI matrix (if requested; ai), both in sigma scale.

Examples


## Not run: 
asr.oats <- asreml(
  fixed = yield ~ Variety * Nitrogen,
  random = ~ Blocks / Wplots,
  data = oats)

gamma2sigma(asr.oats)

## End(Not run)
[Package asreml version 4.2.0.480 Index]