A few things that make life easier

Imagine that you wish to generate a sequence of numbers in the interval -2.1 to 0.5 (including -2.1 and 0.5) with an incremental spacing of 0.2. This is rather tedious to do by hand and is very error prone, because it involves typing a lot of digits. Fortunately, Octave provides you with a very convenient way to do this (note that we now assign the variable b a new value):

octave:60> b = [-2.1:0.2:0.5]
b =
Columns 1 through 7
-2.1000 -1.9000 -1.7000 -1.5000 -1.3000 -1.1000 -0.9000
Columns 8 through 14
-0.7000 -0.5000 -0.3000 -0.1000 0.1000 0.3000 0.5000

If we had done this by hand instead, we should have typed in:

octave:61> size(b)
ans =
1 14

14 numbers. You can also use negative increments if the interval starting value is larger than the end value. If you do not provide an incremental value, Octave assumes 1.

An important point is that if we have chosen an increment of, say 0.4, in Command 60, Octave will give us a number sequence starting from ...