func (this *IWPosterior) NextCovar() (Sigma *matrix.DenseMatrix) {
if this.covarSampler == nil {
this.covarSampler = stat.InverseWishart(this.M+this.S.Count, this.getPsiHat().Arrays())
}
Sigma = matrix.MakeDenseMatrixStacked(this.covarSampler())
return
}
func (this *IWPosterior) NextPrecision() (Sigma *matrix.DenseMatrix) {
if this.precSampler == nil {
psiHatInv, _ := this.getPsiHat().Inverse()
this.precSampler = stat.Wishart(this.M+this.S.Count, psiHatInv.Arrays())
}
Sigma = matrix.MakeDenseMatrixStacked(this.precSampler())
return
}