Normally I'd just upvote and move on, but this is really fucking good. For example, I wish I could have seen something like that "Sine Wave Aliasing" page when I was learning this stuff, would have saved me a lot of confusion.
This is awesome. Congratulations! It should be thrown in the face of the textbook publishing industry that still charges $100+ dollars for yearly reprints of paper bricks.<p>This is what the textbooks should be in the 21st century! Outstanding work and hopefully it will inspire new generation of academics to take the outdated textbook publishing monopolies out of the loop in the future.
This is one of the best pieces of expository writing I've ever seen. I particularly love the interactive phasor visualisation here: <a href="http://jackschaedler.github.io/circles-sines-signals/dft_introduction.html" rel="nofollow">http://jackschaedler.github.io/circles-sines-signals/dft_int...</a>
I wish they could have done things like this when I was learning signals and transforms as an undergrad. But interactive didn't really exist in the early 90s.
This is an _incredibly_ well-crafted piece of work. I mean -- my god -- the pressure wave animation? [1]<p>1: <a href="http://jackschaedler.github.io/circles-sines-signals/sound.html" rel="nofollow">http://jackschaedler.github.io/circles-sines-signals/sound.h...</a>
Like!! It took me a while to chew through signals and FT back in school (before the web) so I really appreciate how this is bringing browser-based animations to the general public. It's a lot easier to understand that way.
This is a wonderful piece of work. Exceptionally clear writing and excellent use of interactivity.<p>One minor bug report, the mathematical pi symbol (U+1D6D1) used in the unit circle doesn't appear to be displayed correctly (Chrome 40, Windows 7): <a href="https://i.imgur.com/zt0HDLO.png" rel="nofollow">https://i.imgur.com/zt0HDLO.png</a>. It's okay in Firefox though.
This is truly outstanding. I'd love to see an entire series done like this.<p>Maybe you could Kickstarter this, and use it as a template for a series of DSP/Electronics/Physics titles?
It seems like the equation processing gets messed late in section 4 - $$ \mathrm{DFT}[k] = \sum_{n=0}^{N-1} \mathrm{x}[n] \cdot (cos(\varphi) - sin(\varphi)i) \\ where \quad \varphi = k \frac{n}{N} 2\pi $$<p><a href="https://jackschaedler.github.io/circles-sines-signals/dft_walkthrough.html" rel="nofollow">https://jackschaedler.github.io/circles-sines-signals/dft_wa...</a><p>there are a few other examples in section 5<p>Aside from that, this is really great.
This is incredible. I wish more professors in universities incorporated this stuff in their teaching. I occasionally use Wolfram Demonstrations: <a href="http://demonstrations.wolfram.com/" rel="nofollow">http://demonstrations.wolfram.com/</a><p>But you take it to another level! Congratulations!
Did you use a tool to make the interactive diagrams, or just write all of them by hand?<p>(I can imagine myself forever tweaking each diagram, and having to cut back on them, but you've created them everywhere they might be useful - it's a fantastic site)
Hi Jack, awesome work! Did you write the HTML by hand or did you use or write some static generator? I'd love to have sidenotes like yours automatically generated and positioned.