search for: classfreq

...um over its elements the sum function returns 0 - this is obviously misleading. Better would be to return NA and give a corresponding warning. There should be a unified strategy to handle vectors of length 0. For example the functions sum, mean, sd handle such vectors in a different way example: classfreq <- c(3,3,3,3); classfreq <- classfreq[classfreq != 3]; sum(classfreq); mean(classfreq); sd(classfreq);