Ismael Garrido wrote:
> Hello
>
> Is there any way to get the fourier series expansion for the unit step
> function?
> If I define the function as f(x):= if x>0 then 1 else 0, then
> totalfourier doesn't know how to integrate that and thus can't return
> the series.
>
Several items
1) There is no Fourier "series" for a unit step function, there is a
Fourier/Laplace transform
2) You are asking for an integration that involves a pole at x=0, so
there might (or might not) be a problem depending upon whether you do it
numerically or symbolically.
3) The simplest approach is to take the transform of the delta function
and then integrate; which means divide by s in the case of the Laplace
xform; similarly for the Fourier transform. You can extend this
approach for more complicated expressions. In fact this approach can be
extended to any transient polynomial stimulus.
RayR