I am new to Mathematica. I try to do a DTFT using FourierSequenceTransform of sin()+cos(). The following are my attempts with different results. How to explain the difference
attempt 1:
dtft1=FourierSequenceTransform[Sin[1/2 Pi n], n, w]
dtft2=FourierSequenceTransform[Cos[1/4 Pi n],n, w]
This (dtft1+dtft2) gives the correct result
attempt 2:
dtftall=FourierSequenceTransform[Sin[1/2 Pi n]+Cos[1/4 Pi n], n, w]
The result of this line is 0
what went wrong ?
Version 9.01, windows 7, I do not get zero
dtftall = FourierSequenceTransform[Sin[1/2 Pi n] + Cos[1/4 Pi n], n, w]
gives
and the results are the same:
Simplify[dtftall - (dtft1 + dtft2)]
gives
0
Which version are you using?
Thanks for your reply. Really appreciate it.
I use ver 8.0.4.0. windows 7. Obviously, there might be a little unexpected behaviour here with Ver. 8. I don’t know what to do. I am currently thinking about upgrading to the latest version.