SlalomModel: SlalomModel C++ class
In PMBio/slalom: Factorial Latent Variable Modeling of Single-Cell RNA-Seq Data

A C++ class for SlalomModel models.

`Y_init`	matrix of expression values
`pi_init`	G x K matrix with each entry being the prior probability for a gene g being active for factor k.
`X_init`	matrix of initial factor states (N x K)
`W_init`	G x K matrix of initial weights
`prior_alpha`	numeric vector of length two giving prior values for the gamma hyperparameters of the precisions
`prior_epsilon`	numeric vector of length two giving prior values for the gamma hyperparameters of the residual variances