R/tam_mml_update_stochastic_nodes.R

In TAM: Test Analysis Modules

## File Name: tam_mml_update_stochastic_nodes.R
## File Version: 0.11

tam_mml_update_stochastic_nodes <- function(theta0.samp, variance, snodes, beta,
        theta)
{
    if ( is.array(variance) ){
        # adapt nodes with respect to distribution in first group
        dim_variance <- dim(variance)
        if ( length( dim_variance )==3 ){
            variance <- variance[ 1,, ]
            variance <- matrix( variance, nrow=dim_variance[2], ncol=dim_variance[3])
        }
    }
    #-- compute new mean for each person
    theta <- beta[ rep(1,snodes), ] + theta0.samp %*% chol(variance)
    # calculate density for all nodes
    thetasamp.density <- tam_import_mvtnorm_dmvnorm( theta, mean=as.vector(beta[1,]),
                                sigma=variance )
    # recalculate theta^2
    theta2 <- tam_theta_sq(theta=theta, is_matrix=TRUE)
    #--- OUTPUT
    res <- list( theta=theta, theta2=theta2, thetasamp.density=thetasamp.density)
    return(res)
}