The functions mvt.sampler and mvnorm.sampler can be used to fine-tune the
construction and sampling from the proposal distribution in the importance sampling
algorithm used in the MCEM algorithm to fit latpos models.
mvt.sampler(df,fix.seed=TRUE) # Multivariate Student's t-distribution
mvnorm.sampler(fix.seed=TRUE) # Multivariate normal distribution
a number, the degrees of freedom of the multivariate Student’s t-distribution.
a logical value; if TRUE the seed of the random number generated is reset in each MCEM
iteration to make sure that approximate marginal log-likelihood surface is continuous
while the simulation sample size is constant.
Both functions return a list that contains a function to generate random numbers and to
compute the log-density function of the distribution from which random numbers are