Why doesn't this work?
freq = 10.0*^6 FourierSeries[SquareWave[freq*t], t, 5]
All Mathematica does is throw my expression back at me.
Thanks.
Perhaps the frequency is too high and there is trouble splitting the interval into so many subintervals. Compare
PiecewiseExpand[SquareWave[10*t], 0 < t < 2 Pi] PiecewiseExpand[SquareWave[20*t], 0 < t < 2 Pi]
Perhaps because the frequency is so high that 5 terms are insufficient?
s[t_] := FourierSinSeries[SquareWave[t], t, 5, FourierParameters -> {1, 2 Pi}]; Plot[Evaluate@fs[t], {t, 0, 2 Pi}]