The numerical integration algorithm that we are using in the program splits the time (call it the interval [0,max]) that we want to simulate into small slices of size dt. So max = (number of intervals)*dt. In order to determine the number of iterations needed in the loop, we compute max/dt.
Note that i in the loop is always the index to the last entry in the vectors V and v.
I had trouble with variable names -- I tried using "max" and "end", both of which gave me trouble. "end" is used in "endfunction," "endear," "endwhile." It turns out the "end" is a substitute for any of these. "max" is a function. An easy way to pick this up is to try typing a possible variable name into octave before you use it.