comp.lang.idl-pvwave archive: archive » Inverse transforming a product of FFTs

Home » Public Forums » archive » Inverse transforming a product of FFTs

Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend

Inverse transforming a product of FFTs [message #40047]

Thu, 01 July 2004 09:22

olde_english33
Messages: 7
Registered: June 2004

Junior Member

I have created two arrays of different time series. One is uniformly
random, call it rantime, and the other one is based off of a recorded
set of data values, call it rectime. Consider the following code,
which I have implemented.

specrantime=fft(rantime)
specrectime=fft(rectime)
prod=specrantime*specrectime
yt=fft(prod, 1)

Now, according to the help files, when you take the forward transform,
the sum is multiplied by 1/N, which in my case is 31. My question is
does taking the back transform of a product of two FFTs, both with 31
variables, lose a factor of 31 when taking the inverse transform?
That is, after I have computed the inverse transform, do I still need
to multiply by a factor of 31 to get the right data out?

Report message to a moderator

Previous Topic:	Help calling a DLL from a DLM
Next Topic:	Licensing

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Wed Oct 08 16:52:00 PDT 2025

Total time taken to generate the page: 0.00433 seconds