[R] Barplot - Beginners Question

[Boris Steipe]

On Oct 4, 2015, at 7:39 PM, Duncan Murdoch <murdoch.duncan at gmail.com> wrote:

> You'll get what you want if you use as.matrix(datentabelle)[,1]
> instead of datentabelle[,1].

This happens to work in this particular case, but fails if the data frame contains text columns.
Example:
   datentabelle <- cbind(datentabelle, text = sample(letters, nrow(datentabelle)))
   barplot(as.matrix(datentabelle)[,1])
   R>  Error in -0.01 * height : non-numeric argument to binary operator

Therefore I would get the row names from your data frame with rownames(datentabelle), and use them as the names.arg argument of barplot():

  barplot(datentabelle[,1], names.arg=rownames(datentabelle))

Cheers,
Boris