Internal function that does the backward step for the stepwise IM function.
backward_step_IM(fit, data, formula, interactive_mode = FALSE,
latent_var_current = NULL, latent_var_dropped = NULL,
search = NULL, search_criterion = "AIC", p_threshold = 0.2,
exclude_worse_AIC = TRUE, max_steps = 100, cv_iter = 5,
cv_folds = 10, folds = NULL, Huber_p = 1.345,
classification = FALSE, start_latent_var = start_latent_var,
eps = 0.01, maxiter = 100, family = gaussian, ylim = NULL,
seed = NULL, print = TRUE)
Current best fit.
If TRUE, the initial dataset is empty.
Same parameters as in the stepwise function.
Returns fit, start_latent_var, latent_var_current and latent_var_dropped.