Xt_siginv_X: Internal computation function
Description
Internal function used compute the products
in cross-sectional VB algorithm and Gibbs sampler
Usage
Xt_siginv_X(tx, siginv, y = NULL)
Arguments
- tx
transpose of the X design matrix
- siginv
inverse variance matrix
- y
outcome matrix. if NULL
, function computes
first product; if not, function computes second product.