estep1: First E step of the AECM algorithm when fitting a mixture of...

In MetabolAnalyze: Probabilistic Latent Variable Models for Metabolomic Data

Description

Internal function required for fitting a mixture of PPCA models.

Usage

estep1(Y, Tau, Pi, mu, W, Sig, g, p, reset)

Arguments

Y	A N x p data matrix.
Tau	A N x G matrix of posterior group membership probabilities.
Pi	A G vector of mixing proportions.
mu	A p x G matrix containing the mean for each group.
W	An p x q x G array of loadings for each group.
Sig	A scalar; the error covariance.
g	The number of groups currently being fitted.
p	Number of spectral bins in the NMR spectra.
reset	Logical indicating computational instability.

Details

First E step of the AECM algorithm when fitting a mixture of PPCA models. An internal function.

Value

A list containing

Tau	The N x G matrix of posterior group membership probablities.
logTau	An N x G matrix of the log of the numerator of posterior group membership probablities.
reset	Logical indicating computational instability.

Note

An internal function.

Author(s)

Nyamundanda Gift, Isobel Claire Gormley and Lorraine Brennan

References

Nyamundanda, G., Gormley, I.C. and Brennan, L. (2010) Probabilistic principal components analysis for metabolomic data. Technical report. University College Dublin, Ireland.

See Also

mppca.metabol

MetabolAnalyze documentation built on Aug. 31, 2019, 5:05 p.m.