Using MATLAB to define a function in signal processing 101

Question

I want to define a function $y(t)$ that has 2 cases:

$$y(t)= \begin{cases} -1 & \text{for} & -T \lt t \leq 0 \\ 1 & \text{for} & 0 \lt t\leq T \end{cases} $$ where $T$ is an integer.

I already defined $t$ using linspace between $-T$ to $T$ in a resolution of 1000 points.

I was advised to use the command ones, but I dont know how to apply it by the function terms.

Thank you.

Answer 1

Well, this is Octave but should work in Matlab:

function y=Y(t)
  y=ones(size(t));
  y=y+(t<=0)*(-2);

.. and it is vectorised. Calling will look like:

>t=linspace(-T,T,1000);
>y=Y(t);

To make this more general we could also make the time at which the function switches a parameter also:

function y=Y(t,S)
  y=ones(size(t));
  y=y+(t<=S)*(-2);