@J Wang
Your output magnitude seems better than the answer given on the thread you have linked however that is still magnitude squared ... the magnitude of a complex number
z = a + ib
is calculated as
|z|=sqrt(a^2+b^2)
the answer in the linked thread suggests that for pure real inputs the outputs
should be using a2 or a for the output because the values for
a_(i+N/2) = -a_(i),
with b_(i) = a_(i+N/2) meaning the complex part in their table is in the second
half of the output table.
i.e the second half of the output table for an input table of reals is the conjugate of the real ...
so z = a-ia giving a magnitude
|z|=sqrt(2a^2) = sqrt(2)a
so it is worth noting the scaling factors ...
I would recommend looking all this up in a book or on wiki to be sure.
