R/7Step3Invariance.r

In LeonieVm/lmfa: Latent Markov Factor Analysis for Exploring Measurement Model Differences in Intensive Longitudinal Data

#' Evaluating for which individuals invariance holds across all measurement occasions
#'
#' \code{invariance} evaluates for which individuals invariance holds across all measurement occasions based on the \code{step3} output.
#' 
#' 
#'
#'
#'
#'
#' @param model  Output from the main function step3() (must be of class lmfa_step3).
#' @param identifier The name of the column containing the subject identifiers (must be a single character).
#
#'
#'
#' @examples
#' \dontrun{
#' invariance(model, identifier)
#' }
#' @export


invariance <- function(model, identifier){
        if(missing(model)) stop("argument data is missing, with no default")
        if(missing(identifier)) stop("argument identifier is missing, with no default")
        if(class(model)!="lmfa_step3") stop("model must be of class lmfa_step3")


        dataInvariance <- model$data
        invariance_time <- c()
        statemembership <- c()
        subjects <- unique(dataInvariance[,identifier])
        for(i in 1:length(subjects)){
        subject_number <- unique(dataInvariance[,identifier])[i]

        #if within perosn invariance holds...
        if(length(unique(dataInvariance[dataInvariance[,identifier]==subject_number,"Modal"]))==1){
            invariance_time <- c(invariance_time,subject_number)
            statemembership <- c(statemembership,unique(dataInvariance[dataInvariance[,identifier]==subject_number,"Modal"]))
        }
        }
        #if it holds for anyone...
        if(!is.null(statemembership)){
            statemembership <- as.matrix(statemembership,ncol=1)
            rownames(statemembership) <- invariance_time


        invariance_subjects <- list()
        for(i in 1:length(sort(unique(statemembership)))){
        invariance_subjects[[i]]<- as.numeric(row.names(statemembership)[which(statemembership==i)])
        }

        names(invariance_subjects) <- paste("S",sort(unique(statemembership)),sep="")

            for(i in 1: length(invariance_subjects)){
                cat(names(invariance_subjects)[i])
                cat("\n")
                
                cat(invariance_subjects[[i]])
                cat("\n")
                cat("\n")
            }

        #if it does not hold for anyone...
        }else{

        x_n_state <- 1:model$n_state
        invariance_subjects <- list()
        for (i in 1:length(x_n_state)) {
        invariance_subjects[[x_n_state[i]]] <- NA
        }

        names(invariance_subjects) <- paste("S",1:model$n_state,sep="")
            for(i in 1: length(invariance_subjects)){
                cat(names(invariance_subjects)[i])
                cat("\n")
                
                cat(invariance_subjects[[i]])
                cat("\n")
                cat("\n")
            }

        }

}