diff --git a/R/podium.R b/R/podium.R
index e5d769d..a853f4d 100644
--- a/R/podium.R
+++ b/R/podium.R
@@ -1,163 +1,221 @@
+#' @export
 podium <- function(object,...) UseMethod("podium")
+
+#' @export
 podium.default <- function(object, ...) stop("not implemented for this class")
 
+#' Creates podium plots
+#'
+#' Creates podium plots from one or more ranked assessment data sets.
+#'
+#' @param object The ranked asssessment data set.
+#' @param xlab A string specifying the x-axis label.
+#' @param ylab A string specifying the y-axis label.
+#' @param lines.show
+#' @param lines.alpha
+#' @param lines.lwd
+#' @param col
+#' @param lines.col
+#' @param dots.pch
+#' @param dots.cex
+#' @param places.lty
+#' @param places.col
+#' @param legendfn
+#' @param layout.heights
+#' @param ... Further arguments passed to or from other functions.
+#'
+#' @return
+#'
+#' @examples
+#'
+#' @seealso `browseVignettes("challengeR")`
+#'
+#' @family functions to visualize assessment data
+#' @export
 podium.ranked.list=function(object,
-                            xlab = NULL,
-                            ylab = NULL,
+                            xlab = "Podium",
+                            ylab = "Performance",
                             lines.show = TRUE,
                             lines.alpha = 0.2,
                             lines.lwd = 1,
                             col,
                             lines.col = col,
                             dots.pch = 19,
                             dots.cex = 1,
                             places.lty = 2,
                             places.col = 1,
                             legendfn = function(algs, cols) {
                               legend("topleft", algs, lwd = 1, col = cols, bg = "white")
                             },
                             layout.heights=c(1,0.4),
                             ...){
-    if (is.null(xlab)) xlab <- "Podium"
-    if (is.null(ylab)) ylab <- "Performance"
     x=object$data
 
     podiumPlots <- length(names(x))
 
     for (subt in names(x)) {
       ordering=t(object$matlist[[subt]][,"rank",drop=F])["rank",]
       if (missing(col)) col=default_colors(length(ordering),
                                            algorithms = names(ordering))
 
       dd=as.challenge(x[[subt]],
                       value=attr(x,"value"),
                       algorithm=attr(x,"algorithm"),
                       case=attr(x,"case"),
                       by=attr(x, "by"),
                       annotator = attr(x,"annotator"),
                       smallBetter = attr(x,"smallBetter"),
                       na.treat=object$call[[1]][[1]]$na.treat)
 
       podiumPlot <- podium(dd,
              ordering=ordering,
              xlab = xlab, ylab = ylab,
              lines.show = lines.show,
              lines.alpha = lines.alpha,
              lines.lwd = lines.lwd,
              col=col,
              lines.col = lines.col,
              dots.pch = dots.pch,
              dots.cex = dots.cex,
              places.lty = places.lty,
              places.col = places.col,
              legendfn = legendfn,
              layout.heights=layout.heights,
              ...)
 
       if (length(names(x)) > 1) {
         title(subt,outer=T,line=-3)
       }
 
       append(podiumPlots, podiumPlot)
     }
 }
 
+#' Creates a podium plot
+#'
+#' Creates a podium plot from a challenge object.
+#'
+#' @param object The challenge object.
+#' @param ordering
+#' @param xlab A string specifying the x-axis label.
+#' @param ylab A string specifying the y-axis label.
+#' @param lines.show
+#' @param lines.alpha
+#' @param lines.lwd
+#' @param col
+#' @param lines.col
+#' @param dots.pch
+#' @param dots.cex
+#' @param places.lty
+#' @param places.col
+#' @param legendfn
+#' @param layout.heights
+#' @param ...
+#'
+#' @return
+#'
+#' @examples
+#'
+#' @seealso `browseVignettes("challengeR")`
+#'
+#' @family functions to visualize assessment data
+#' @export
 podium.challenge=function(object,
                           ordering,
                           xlab = NULL, ylab = NULL,
                           lines.show = FALSE, lines.alpha = 0.2,
                           lines.lwd = 1,
                           col,lines.col = col,
                           dots.pch = 19, dots.cex = 1,
                           places.lty = 2, places.col = 1,
                           legendfn = function(algs, cols) {
                             legend("topleft", algs, lwd = 1, col = cols, bg = "white")
                           },
                           layout.heights=c(1,0.4),
                           ...) {
 
   ranking=object%>%rank( ties.method = "random" )
 
   task <- ranking$matlist[[1]]
 
   dat=as.data.frame(table(task[[attr(object, "algorithm")]],
                           task$rank,
                           dnn=c("algorithm","rank")),
                     responseName = "Count")
 
   form=as.formula(paste(attr(object,"case"), attr(object,"algorithm"), sep="~"))
   ranks=acast(task, form, value.var="rank")
   values=acast(task, form, value.var=attr(object, "value"))
   nranks=acast(dat, algorithm~rank, value.var="Count")
 
   nalgs <- ncol(ranks)
   algs <- colnames(ranks)
 
   barorder <- order(ordering)
   orderedAlgorithms= names(ordering)[barorder]
 
   ylim=range(task[[attr(object,"value")]], na.rm = TRUE)
 
   dotplotborders <- (0:nalgs) * nalgs
   dotplaces <- (1:nalgs) - 0.5
   names(dotplaces) <- orderedAlgorithms
 
   linecols <- sapply(lines.col, function(c) {
     r <- col2rgb(c)
     rgb(r[1], r[2], r[3],
         alpha = round(255 * lines.alpha),
         maxColorValue = 255)
   })
 
   opar <- par(no.readonly = TRUE)
   layout(matrix(c(1, 2), nrow = 2, byrow = TRUE),
          heights =layout.heights)
 
   mar <- par("mar")
   par(mar = c(0, mar[2], mar[3], mar[4]))
 
   plot(dotplotborders, rep(ylim[2], nalgs + 1),
        type = "n",
        ylim = ylim, ylab = ylab, xlab = "",
        axes = F)
   axis(1, at = dotplotborders,
        labels = NA, lwd = par("lwd"))
   axis(2, lwd = par("lwd"))
   box()
   abline(v = dotplotborders, lty = places.lty, col = places.col)
   linesegments <- function(x, y, ...) {
     n <- length(x)
     segments(x[-n], y[-n], x[-1], y[-1], ...)
   }
   drawthe <- function(fn, col, ...) {
     for (i in 1:nrow(values)) {
       r <- ranks[i, ]
       o <- order(r)
       performances <- (values[i, ])[o]
       places <- (dotplaces[names(r)] + ((r - 1) * nalgs))[o]
       fn(places, performances, col = col[names(r)[o]], ...)
     }
   }
   if (lines.show) drawthe(linesegments, linecols, lwd = lines.lwd)
 
   drawthe(points, col, pch = dots.pch, cex = dots.cex)
 
   legendfn(orderedAlgorithms,
            col[orderedAlgorithms])
 
   par(mar = c(mar[1], mar[2], 0, mar[4]))
   barplot(nranks[barorder,],
           beside = TRUE,
           width = 1,
           axes = F,
           space = c(0, 0),
           border = NA,
           ylim = c(0, nrow(ranks)),
           names.arg = paste(1:nalgs, ".", sep = ""),
           col = col[orderedAlgorithms],
           xlab = xlab)
   axis(1, at = c(0, dotplotborders),
        labels = NA, lwd = par("lwd"))
   box()
   par(opar)
 }