as i said before

1)   i want define apicewise symbolic such as " g ":

g := piecewise(0 <= t and t <= 0.2e-1, 122.63, 0.2e-1 < t and t < .287, 0, .287 <= t and t <= .307, 122.63, .307 < t and t < .335, 0);

that " g " is repeated 10 times to t=10*0.335 . and i want to plot it. such az

2) i want to define and plot Fourier amplitude spectrum of picture above such as

 3) i want to define two  filter to omit low amplitude and high frequences of picture above .

4) and then use inverse fft to obtain corrected load- time plot.

5) and form a table of corrected load- time plot in excel.