Fourier transform question:

I have many, many (~1.1 million) FTs to compute. The vast majority of them do not need to be computed with much accuracy. So my idea is to obtain points on the envelope by computing the integral at a very big number (instead of at infinity) and then interpolating the rest of the curve with splines. I can then run the FFT as usual on a much smaller set of the ~1.1 million.

Can someone confirm whether or not this a sensible approach?

Question

Fourier transform question:

I have many, many (~1.1 million) FTs to compute. The vast majority of them do not need to be computed with much accuracy. So my idea is to obtain points on the envelope by computing the integral at a very big number (instead of at infinity) and then interpolating the rest of the curve with splines. I can then run the FFT as usual on a much smaller set of the ~1.1 million.

Can someone confirm whether or not this a sensible approach?