# [PD] fft beginner question

cristiano figueirÿfffff3 figocris at yahoo.com.br
Tue Nov 20 17:21:48 CET 2007

```Hi, thanks for help, now i'm begining to understand :)

hard off:

"pd's default block size is 64 samples, which is
why you get 64 numbers for each FFT analysis in pd
with default block
size."

ok, that i understand, i'll make some tests with this
value...to modify the default i call the block~ object
rigth?

"Complex
numbers are just pairs of numbers as well. FFT gives
out cartesian
coordinates (re = x, im = y) that are connected to
phase and
magnitude, if you view the latter as the respective
polar coordinates
for that fft-bin."

So, each pair is one number from real and the
respective from imaginary? (the first from real and
first from imag. for example?).

In my example, when i first select the frequency
"0"(hertz) for my osc~ (who is gonna be analyzed) why
this number (-39.604) appears?

real:
-39.604  0        0        0        0        0
0        0
0        0        0        0        0        0
0        0
0        0        0        0        0        0
0        0
0        0        0        0        0        0
0        0
0        0        0        0        0        0
0        0
0        0        0        0        0        0
0        0
0        0        0        0        0        0
0        0
0        0        0        0        0        0
0        0
imaginary:
0        -0       -0       -0       -0       -0
-0       -0
-0       -0       -0       -0       -0       -0
-0       -0
-0       -0       -0       -0       -0       -0
-0       -0
-0       -0       -0       -0       -0       -0
-0       -0
0        0        0        0        0        0
0        0
0        0        0        0        0        0
0        0
0        0        0        0        0        0
0        0
0        0        0        0        0        0
0        0

thanks
cristiano

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