Velocity Reviews > meaning of numpy.fft coefficients

meaning of numpy.fft coefficients

Joey
Guest
Posts: n/a

 07-09-2011
the list generated by numpy is of form [ a+bi, c+di, ...]

could anybody tell me the meaning of the coefficients a and b? I am

information provided by numpy reference says Ak = Sum of a[m] *
exp{-2*pi * i * m * k / n} for m from 0 to n-1

Which part is a and which part is b and what is the meaning of each
part?

Corey Richardson
Guest
Posts: n/a

 07-09-2011
Excerpts from Joey's message of Fri Jul 08 20:14:29 -0400 2011:
> the list generated by numpy is of form [ a+bi, c+di, ...]
>
> could anybody tell me the meaning of the coefficients a and b? I am
> very confused about fourier transform!
>

a+bi is a typical complex number. a is the real part, b is the imaginary.
Python uses j,

>>> 4+5j

(4+5j)

http://en.wikipedia.org/wiki/Complex_number
http://docs.python.org/library/stdty...l#typesnumeric
--
Corey Richardson
"Those who deny freedom to others, deserve it not for themselves"
-- Abraham Lincoln

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.17 (GNU/Linux)

iQEcBAEBCAAGBQJOF6ZLAAoJEAFAbo/KNFvp/bgIALFheebo4WVL9/jOg4m4HWQG
D+R5IpCedugzQYWVLWwoYXPw8LdacUi7BGpf6pv/61Aqi8xFKCN09LnXg42WLGc4
TOmiA7RxASW1FVis1v6hIoC6CYXQLCEDw8pTdCaZn6soCQXvED OtiSUkPgXW5nPD
sQWATQ9vW2ZtEj+xrQo7i2EiRpNLKi/SIuHzazWWYEOk1EYppxDzZkjQbY3nYwTm
ag0O4elNsdUXMEHhi2iO6tOQ71N7MJ+CpRlqcHihG/E5YWIrY+8+EAo1sJNn9Vot
=Jiso
-----END PGP SIGNATURE-----