Table 4 Examples for characterizations

function(v) {sum(!is.na(v))}

Count present values in variable

function(v) {mean(abs(diff(v)), na.rm = TRUE)}

Mean density of values in variable

function(v) {#begin_plot

par(las = 2)

par(mar = c(7,4,1,1))

barplot(v, main = NULL, xlab = NULL, names = item1, col = rainbow(length(v)))

#end_plot}

Plotting a barplot for variable’s values

(Before execution #begin_plot and #end_plot markers are replaced with R-code to integrate the resulting plot with openCQA)