relfactor {pedigreemm}

Relationship factor from a pedigree...

Description

Relationship factor from a pedigree

Usage

relfactor(ped, labs)

Arguments

ped

a pedigree that includes the individuals who occur in labs

labs

a character vector or a factor giving the labels to which to restrict the relationship matrix. If labs is a factor then the levels of the factor are used as the labels. Default is the complete set of labels in the pedigree.

Details

Determine the right Cholesky factor of the relationship matrix for the pedigree ped, possibly restricted to the specific labels that occur in labs.

Value

an upper triangular, sparse (right) Cholesky factor of the relationship matrix

References

2010. A.I. Vazquez, D.M. Bates, G.J.M. Rosa, D. Gianola and K.A. Weigel. Technical Note: An R package for fitting generalized linear mixed models in animal breeding. Journal of Animal Science, 88:497-504.

Examples

## Example from chapter 2 of Mrode (2005)

ped <- pedigree(sire = c(NA,NA,1, 1,4,5),
                dam  = c(NA,NA,2,NA,3,2), label= 1:6)
(fac <- relfactor(ped))
crossprod(fac)    # the relationship matrix
getA(ped)         # the relationship matrix