Re: Fourier transform
Fourier transform is basicly a thematical tool to convert waveform in time domain to frefrequency domain.
Let say we have a picture of a wave for 5 second. A math major will say that they can represent that arbitrary wave ( 5 s ) with a series of sin and cos function.
So how can wave be convert from time to frequency domain???
well, it's like integration and differential equation, we need two or point to be able to determine derivative of a function. Same with fourier transform, We take advantage of knowing ahead of time the wave and convert it to frequency domain.
There is no such thing like instantaneous transform because it's not exist.
Hope it will help