How to calculate the amplitude of sweep waveform?

[owenwan]

Hi My Dear All,

I have got a time domain swept waveform by sound card (24bit), now I will calculate the amplitude of swept waveform by freqency domain array, but I don't konw how to get these Amp results by freqency list (range: 20Hz~20KHz), so your warmly help wil be appreciated, thanks!

Best regards,

owen

[aeastet]

Is this what you need?

[owenwan]

it is't what I need, I need the amplitude of swept waveform by freqency list, such as (waveform 1: x = 20Hz y= 0.058Vdc, x=300Hz, y=0.04Vdc), So we will translate time domain signal to freqency domain, that will can get the amplitude of waveform (Y) by freqency domain (X), thanks for your reply!

[Ryan.C]

Actually I think the attachment is almost fine. You said the expected result should be a freqency list, but you didn't give specific points on X-axis. Thus this VI uses a search function to find the amplitude for any frequency you want.

If you know at what freq. points you would like to have the amplitude, please just first do a FFT convertion, and then use search and setup array function to get the list.