It's amazing that this resource is available for free
5 stars
I really love how this book starts from the fundamentals and builds up to the discrete Fourier transform. The idea of the frequency domain and time domain being different coordinates in the same space is also something that blew my mind. It makes sense when you study it, but it's not something that was immediately obvious to me. I'm definitely going to go on to the next book in the series about filters. 10/10 would recommend.