AnsweredAssumed Answered

vrf ifft amplitude scaling

Question asked by VRFuser on Apr 18, 2006

Unless you have a particular need to have the "correct" absolute scale in the frequency domain, I would not use the scaling function. Just do the FFT, multiply by your filter function and do the IFFT.
Bill Ossmann
Philips Ultrasound

"Nick Evans" <> wrote on 04/18/2006 11:39:16 AM:

> Hi All
> Can anyone point me in the direction of how to scale the amplitude
> of an inverse fft.   Vee has an example of how to scale the
> amplitude of an fft such that the spectral peaks in the frequency
> domain have amplitudes equal to those in the time domain.  I am using
> this function basically to convert a waveform into the frequency
> domain.  Then I’m manipulating the data with some shaping curves and I
> want to convert it back to the time domain.  The problem is that if I
> strictly reverse the process in the “scale fftâ€
> it does not always give me the correct amplitude back in the time
> domain.   I sometimes end up with huge numbers in the time domain.
> Any help would be greatly appreciated.
> Thanks
> Nick
> ---
You are currently subscribed to as: %%emailaddr%% To subscribe please send an email to: "" with the word subscribe in the message body.
To unsubscribe send a blank email to "".
To send messages to this mailing list,  email "". 
If you need help with the mailing list send a message to "".
Search the "unofficial vrf archive" at "".