R/batch_chisq.R

In prestevez/victim: Victimisation Analysis and Reporting

#' Batch Chi-square Tests
#'
#' A wrapper for \code{\link{chisq_wrap}} to enable batch processing
#' of Chi-square tests of association between one DV and a vector of
#' at least 1 IV.
#'
#' @param df The data frame that contains the \code{IV} and \code{DV}
#' @param DV A column name containing a factor variable, will be the columns
#'     of the chi-sq contingecy tables.
#' @param IV A vector of column names of \code{length(IV) >= 1} containing
#'     factor variables.
#' @param ... pases options to the child functions, e.g. the number of
#'     replicates to use in simulation \code{B = 1000}.
#' @keywords chi-squared
#' @export
#' @examples
#' batch_chisq(df = testdata, DV = "extortion_victim",
#'             IV = c("bribe_victim", "size"))

batch_chisq <- function(df, DV, IV, ...)
{
    if(class(df[,DV]) == "factor")
    {fac_dv <- df[,DV]}
    if(class(df[,DV]) %in% c("numeric", "integer"))
    {fac_dv <-  fac_relevel(df[,DV])}
    if(class(fac_dv) != "factor")
    {stop(paste(DV, " cannot be coerced into a factor", sep =""))}

    results <- list()

    for(i in 1:length(IV))
    {
        if(class(df[,IV[i]]) == "factor")
        {fac_iv <- df[,IV[i]]}
        if(class(df[,IV[i]]) %in% c("numeric", "integer"))
        {fac_iv <- fac_relevel(df[,IV[i]])}
        if(class(fac_iv) != "factor")
        {stop(paste(IV, " cannot be coerced into a factor", sep =""))}

        freqtable <- ftable(fac_iv,  fac_dv)

        names(attr(freqtable, which = "col.vars")) <- DV
        names(attr(freqtable, which = "row.vars")) <- IV[i]

        chsqtst <- chisq_wrap(freqtable, ...)

        chsqtst$data.name <- paste0(DV, " vs. ", IV[i])

        results[[IV[i]]] <- chsqtst

    }
    return(results)
}