brettbuddinon Lobsters • Recommends
But what is the Fourier Transform? A visual introduction. (2018)
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#fouriertransform#signalprocessing#3blue1brown
But what is the Fourier Transform? A visual introduction.
3Blue1Brown
8.7M subscribers • 42 videos on Hallway
- Recommended by 17 people: 16 on Hacker News and 1 on Lobsters.
- A classic. People kept recommending it from 2019 to 2025.
- Presented by Grant Sanderson, creator of 3Blue1Brown
- Linked in the descriptionthatSaneKid/fourier3b1b/manim
Beginner. No background in the topic needed.
12M views8 years ago17 recommendations
Computer scienceGraphics and audioMath for programmersAlgorithmsAudio and DSP
Grant Sanderson provides an animated, visual explanation of how the Fourier transform decomposes a signal into its individual frequencies.
An animated introduction to the Fourier Transform. Help fund future projects: patreon.com/3blue1brown An equally valuable form of support is to simply share some of the videos. Special thanks to these supporters: 3b1b.co/fourier-thanks Learn more about Janestreet: janestreet.com/3b1b Follow-on video about the uncertainty principle: youtu.be/MBnnXbOM5S4 Interactive made by a viewer inspired by this video: prajwalsouza.github.io/Experiments/Fourier-Transform-Visuali… Also, take a look at this Jupyter notebook implementing this idea in a way you can play with: github.com/thatSaneKid/fourier/blob/master/Fourier%20Transfo… Thanks to these viewers for their contributions to translations Hebrew: Omer Tuchfeld Russian: xX-Masik-Xx Vietnamese: @ngvutuan2811 ------------------ Animations largely made using manim, a scrappy open-source python library. github.com/3b1b/manim If you want to check it out, I feel compelled to warn you that it's not the most well-documented tool, and has many other quirks you might expect in a library someone wrote with only their own use in mind. Music by Vincent Rubinetti. Download the music on Bandcamp: vincerubinetti.bandcamp.com/album/the-music-of-3blue1brown Stream the music on Spotify: open.spotify.com/album/1dVyjwS8FBqXhRunaG5W5u If you want to contribute translated subtitles or to help review those that have already been made by others and need approval, you can click the gear icon in the video and go to subtitles/cc, then "add subtitles/cc". I really appreciate those who do this, as it helps make the lessons accessible to more people. ------------------ 3blue1brown is a channel about animating math, in all senses of the word animate. And you know the drill with YouTube, if you want to stay posted on new videos, subscribe, and click the bell to receive notifications (if you're into that). If you are new to this channel and want to see more, a good place to start is this playlist: 3b1b.co/recommended Various social media stuffs: Website: 3blue1brown.com Twitter: twitter.com/3Blue1Brown Patreon: patreon.com/3blue1brown Facebook: facebook.com/3blue1brown Reddit: reddit.com/r/3Blue1BrownWhy it's here
17 people recommend thisWhat people say. Highly recommended as the clearest visual explanation of the Fourier transform and how it works.
justjonathanon Hacker News • Recommends
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This is an explanation (from the amazing three blue one brown) of the DFT not the DCT, but this was the first thing that ever really made sense to me. It is explained by someone who really knows math incredibly well and is an amazing teacher, with amazing visuals: link to this video
andybakon Hacker News • Recommends
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Dude really needs to subscribe to 3Blue1Brown: link to this video (but anyone interested in stuff like this should be. I guess I'm surprised to see someone like this writing a blog post who isn't regularly checking out that channel)
faebion Hacker News • Recommends
On “Ask HN: Videos that changed your life or how you think”
I never understood how multiple electrical frequencies can be in a copper cable. I always thought they must merge and therefore it must be impossible to find the right set of original frequencies and their strength. Then I learned about the Fourier transform in this beautiful video: link to this video
SJSqueon Hacker News • Recommends
On “Demystifying Fourier analysis”
I can also highly recommend 3Blue1Brown's treatment of the topic: link to this video (...which I see now is cited in the video that you link to!)
sjaakon Hacker News • Recommends
On “Ask HN: Concepts that clicked only years after you first encountered them?”
This is what made it click for me, can recommend it: 3Blue1Brown -- But what is the Fourier Transform? A visual introduction. link to this video
TimSchumannon Hacker News • Recommends
On “3Blue1Brown Calculus Blog Series”
Grant makes some amazing content. His visualization of the Fourier Transform1 actually enabled me to understand the how it was happening behind the what was happening with one of the most used algorithms in computing. 1 link to this video
garbagemanon Hacker News • Recommends
On “How the cochlea computes (2024)”
It's an absolutely brilliant bit of maths that breaks a complex waveform into the individual components. Kind of like taking an orchestral song and then working out each individual instrument's contribution. Learning about this left me honestly aghast and in shock that it's not only possible but that someone (Joseph Fourier) figured it out and then shared it with the world. This video does a great job explaining what it is and how it works to the layman. 3blue1brown - link to this video
pdkl95on Hacker News • Recommends
On “Why have so many physicists shrugged off the paradoxes of quantum mechanics?”
…ave packet only a few wavelengths long correlates with a narrow (precise) range of positions, but also correlates well with a very wide range of frequencies due. A Heisenberg-like uncertainty exists any time you are working with weave packets with length near the wavelength. 3Blue1Brown gives a very good example using Doppler radar. 1 link 2 link to this video…
quickthrower2on Hacker News • Recommends
On “The “Windmill” Problem on the 2011 International Mathematical Olympiad [video]”
I recommend watching the "But what is the Fourier Transform? A visual introduction." link to this video . Beautiful.
jmiserezon Hacker News • Recommends
On “Show HN: SHA-256 Animation”
3blue1brown is great, e.g. his Fourier transform animation is super intuitive: link to this video He has opensourced his animation engine "manim" used in his videos: link
itissidon Hacker News • Recommends
On “An Interactive Guide to the Fourier Transform (2012)”
What about the 3 blue 1 brown video on it? I think that is pretty concise and intuitive too but does not seem to appear on this thread link to this video
ryan-duveon Hacker News • Recommends
On “Shor, I’ll do it (2007)”
If the part about the tack on the board under the clocks wasn't clear, and you're a visual learner, this video from 3Blue1Brown about the classic Fourier Transform might help clarify the relationship to periodicity: link to this video
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There's no all in one stop for understanding radio but these 5 resources helped me a lot. The RF Get Down courses. This is by far the best material online to learn RF and how modulation works: link 3blue1brown's video tutorial on the fourier transform: link to this video AT&T Archives: Similiarities of Wave Behavior link Quadrature Signals: Complex, But Not Complicated by Richard Lyons, link link Antenna Theory's website and forums, link I also highly recommend getting a $20 rtl-sdr USB software defined radio dongle. They're great toys for learning RF, what modulation is , and exploring the spectrum.
sizzzzlerzon Hacker News • Recommends
On “An Interactive Guide to the Fourier Transform”
Just a nit. The pair of equations the author showed at the beginning of the article are not the equations of the Fourier Transform and its inverse. The Transform is a continuous function operating on an infinite input. The equation for the Transform involves the use of the integral taken over +/- infinity. What is shown, using the summation operator, is a discrete form on the Transform where the input is a limited time series. A good alternative explanation can be found on Grant Sanderson's 3 Blue 1 Brown channel link to this video
mananaysiempreon Hacker News • Recommends
On “Pre-Trained Large Language Models Use Fourier Features for Addition (2024)”
…s, there could be quite a bit of concept debt to pay off before I could really offer something I could honestly call an explanation. Have you tried the 3Blue1Brown video on the topic1? It does not AFAIR offer any answers as to why the Fourier transform should exist or be useful, but it does show very well what it does in the immediate sense. 1 link to this video…