Update time-constant latent node positions using optimized matrix operations. Pre-computes invariant quantities outside the node loop for better performance.
updateU(K, U, V, R, Zb, s2, eU, iVU)A matrix of time-constant latent node positions
The dimensionality of Z
The most recent draw of latent node positions
Layer-specific network generation rule
The dimensionality of latent space
Z - beta
error variance
The mean of U
The variance of U