R/c_wrapper_function.R

In mcgfa: Mixtures of Contaminated Gaussian Factor Analyzers

# This function takes input data in the R format,
# makes the foreign function call to C, and then
# packages the C output in a list.

run_mcgfa <- function(X, z, v, bic, known, q, p, G, N, mu, cov_model, fixed_alpha, fixed_eta,
                      class_ind, Lambda, Psi, eta, alpha, eta_max, alpha_min, tol, max_it, iterations) {

    # R uses column-major order => transpose matrices for C
    X <- as.vector(t(X))
    z <- as.vector(t(z))
    mu <- as.vector(t(mu))
    
    c_out <- .C("mcgfa_c", as.double(X), as.double(z), as.double(v), as.double(bic),
               as.integer(known), as.integer(q), as.integer(p), as.integer(G), as.integer(N),
               as.double(mu), as.integer(cov_model), as.integer(fixed_alpha), as.integer(fixed_eta),
               as.integer(class_ind), as.double(Lambda), as.double(Psi), as.double(eta), as.double(alpha),
               as.double(eta_max), as.double(alpha_min), as.double(tol), as.integer(max_it),
               as.integer(iterations), PACKAGE="mcgfa")
    
    list(z = c_out[[2]],
         v = c_out[[3]],
         bic = c_out[[4]],
         mu = c_out[[10]],
         lambda = c_out[[15]],
         psi = c_out[[16]],
         eta = c_out[[17]],
         alpha = c_out[[18]],
         iterations = c_out[[23]]
    )
}