I've just installed octave 3.2.3 and I'm a complete newbie. What I need most is a quick command to get the area under a curve. The curve is made of columns 1 and 3 of a file like this which I use to plot with gnuplot:
I use to import the file in a spreadsheet and then do a trapezoidal integration "by hand"
sum((y[i-1]+y[i])*(x[i]-x[i-1])/2) for i=2:n
being i the row and n the number of rows.
But this is very time wasting when doing loads of parametric analyses. How can I get this quickly with octave? There would be any difference if the file had a header?