R/plotSS.R

In PeterVerboon/gemm: Moderated mediation with covariates

#' Makes simple slope plots of gemm object
#'
#' @param x   object moderatedMediationSem
#' @param ... optional
#'
#' @return simple slope plots for each mediator and simple slopes parameter estimates
#' @export
#'
plotSS <- function(x,...) {
  
  data <- x$intermediate$data
  xmmod <- x$input$xmmod
  mymod <- x$input$mymod
  xvar <- x$input$xvar
  yvar <- x$input$yvar
  mvars <- x$input$mvars
  xmoderator <- x$input$data[,xmmod]
  ymoderator <- x$input$data[,mymod]
  parEst <- x$intermediate$parameterEstimates
  predLevels <- x$intermediate$predLevels
  xdichotomous <- x$intermediate$xdichotomous
  ydichotomous <- x$intermediate$ydichotomous
  
  if ((!length(xmmod)) & (!length(mymod))) {
    return(message("No plots can be given, because no moderators have been specified"))
  }
  
  xquant <- stats::quantile(data[,xvar],c(.16,.84), na.rm = TRUE)
  if (xquant[1] == xquant[2])  {
    if (!is.null(predLevels))  {
      xquant <- c(0,1)
    } else {
      return(message("The 16th and 84th precentile of the predictor are the same. No plots are made."))
    }
  }
  
  yquant <- stats::quantile(data[,yvar], c(.16,.84), na.rm = TRUE)
  
  ## test if moderator exists for x=m path 
  
  if (length(xmmod)) {
    if (length(unique(xmoderator)) == 2) xmodLevels <- c(0,1)
    if (is.factor(xmoderator)) xmodLevels <- levels(xmoderator)
   
    prepPlotSS(data=data, xvar=xvar, yvar = yvar, mod = xmmod, mvars = mvars, parEst = parEst, 
                 vdichotomous = xdichotomous, modLevels = xmodLevels, predLevels = predLevels, 
                 xquant = xquant, yquant = yquant, path = "x-m")
  }
  
  ## test if moderator exists for m=y path 
  
  if (length(mymod)) {
    if (length(unique(ymoderator)) == 2) ymodLevels <- c(0,1)
    if (is.factor(ymoderator)) ymodLevels <- levels(ymoderator)
    
    prepPlotSS(data=data, xvar=xvar, yvar = yvar, mod = mymod, mvars = mvars, parEst = parEst, 
                 vdichotomous = ydichotomous, modLevels = ymodLevels,predLevels = predLevels, 
                 xquant = xquant, yquant = yquant, path = "m-y")
  }
  
  invisible()
  
}  # end function