[Sprint]

Yeah, I was thinking about that and spent the past minutes to make me some Bash functions like:

  function mean() {
          octave -q --eval "mean = mean(load('$1'))"
  }

Then just run "mean numbers.txt".

I am sure your approach is much quicker, octave takes a good 0.5s(!) to load on my machine.

[nferraz]

Yup, octave requires more time to warm up.

Regarding speed, for simple calculations like sum, mean and variance, the bottleneck is in I/O.