Mattias Petter Johansson (MPJ)
mpj.fff.dev
Mattias Petter Johansson (MPJ)
@mpj.fff.dev
Data Engineer 💛 Creator of the YouTube show Fun Fun Function, writes weekly data development chronicle: funfun.email 🦁Previously @ Spotify & parity.io
Pinned
💛 d3.interpolate (Number) | Dirty D3 - Episode 4
📼 Full video: youtu.be/6Vn1TWyOsYo

#dataviz #d3js #fffn
Reposted by Mattias Petter Johansson (MPJ)
Biggest commitment to a 3 second joke I've ever seen
April 9, 2025 at 6:33 AM
I am reading Daniel Levintins excellent book ”The Organized Mind” and this part perfectly explains why I sometimes get stuck in multi-hour obsessive TypeScript rabbit holes to create the perfectly (unnecessary) typed expression for a problem.
May 31, 2025 at 12:36 PM
I love this format with @bashbunni.dev and I hereby promise publicly to try doing this. Also I so love the aesthetics and idea @charm.sh, makes me feel super great for some reason
www.youtube.com/watch?v=Qpz0...
code with me for 1 hour (cozy, soft typing)
YouTube video by bashbunni
www.youtube.com
May 26, 2025 at 11:18 PM
💛 d3.interpolate (Number) | Dirty D3 - Episode 4
📼 Full video: youtu.be/6Vn1TWyOsYo

#dataviz #d3js #fffn
May 26, 2025 at 3:51 PM
hmm should I make a Rough Regex course after my Dirty D3 series ends (in 2054)
One of these days I’ll learn regex. I promise #dataBS
May 23, 2025 at 9:40 PM
💛🌻🎉 #dataviz
We have a "never use yellow if you can help it" rule for our charts. We couldn't help it on this one
www.economist.com/united-state...
May 23, 2025 at 9:38 PM
God I love force directed graphs
📊 Recent little Observable play - creating an org chart viz using a force directed tree that is zoomable, pannable, collapsable and has a tooltip observablehq.com/@pjpscriv/or...

Not displaying any interesting data atm, but certainly fun to play with!
May 22, 2025 at 9:57 PM
💛It’s seldom one gets shoutouts for commercial partnerships, but @augmentcode.com really is that good - it’s really an incredible thing that a platform targeting large legacy codebases is free for OSS thx @adrienjoly.com
And I would like to also thank @mpj.fff.dev for having inspired me to try it out, and for making awesome videos that I always enjoy watching! <3

If you want to check my changes and the prompts I used, here are the changes I just deployed to openwhyd.org: github.com/openwhyd/ope...
May 21, 2025 at 3:12 PM
New episode! 📽️💛

What is interpolation, really? | Dirty D3 - Episode 3 youtu.be/LOaqG--VWas #dataviz #d3js
What is interpolation, really? | Dirty D3 - Episode 3 (and "default interpolator"?)
YouTube video by Fun Fun Function
youtu.be
May 19, 2025 at 10:09 PM
Reposted by Mattias Petter Johansson (MPJ)
I'm obsessed with this:
Mystical, a visual representation of PostScript as magical symbols. What if software departments were catacombs of hooded figures scratching arcane circles into the dirt
github.com/denismm/myst...

(via @piterpasma.nl)
May 19, 2025 at 11:57 AM
I love love love this example, really visceral way of unstanding variance
Ziet's simulation of potential German election results
www.zeit.de/politik/deut...
May 15, 2025 at 8:29 PM
Great thread on dataviz animation ❤️
What is #dataviz animation good for? An updated thread with examples.
May 15, 2025 at 6:01 PM
Reposted by Mattias Petter Johansson (MPJ)
Humanity may never be able to find a counter-example to Collatz conjecture if this package gets removed from npm.
May 1, 2025 at 11:41 PM
Was sent this golden thing from 3 months ago written by @peck.phd
Trying something new:
A 🧵 on a topic I find many students struggle with: "why do their 📊 look more professional than my 📊?"

It's *lots* of tiny decisions that aren't the defaults in many libraries, so let's break down 1 simple graph by @jburnmurdoch.bsky.social

🔗 www.ft.com/content/73a1...
March 11, 2025 at 1:30 PM
mundus sine caesaribus
March 11, 2025 at 1:07 PM
Are you sure you want to hide the ads in your editor
March 11, 2025 at 10:51 AM
Reposted by Mattias Petter Johansson (MPJ)
We often mind-wander about our past, present, & future. What happens when our minds drift towards our bodies? In a new fMRI study (n ~ 500), @leahbanellis.bsky.social + team discovers unique neural, affective, & physiological correlates of "body-wandering" at rest. www.biorxiv.org/content/10.1...
December 10, 2024 at 8:05 AM
Reposted by Mattias Petter Johansson (MPJ)
Me in the WSJ today, arguing that the relationship between social media and mental health is not clear cut, and bans for teenagers aren't the answer.

(NB I did not pick this title, I would have gone for something kinder. I understand why people are worried.)

1/

www.wsj.com/health/welln...
Essay | Stop Panicking Over Teens and Social Media
Modern life is digital. Adults need to help young people navigate the costs and benefits, not launch bans and hope for the best.
www.wsj.com
February 1, 2025 at 12:39 PM
Reposted by Mattias Petter Johansson (MPJ)
New manuscript published! ✍️👀

Concept neurons evolve from index neurons through overlapping memories.

Check it out here: www.cell.com/trends/cogni... 1/15
On the origin of memory neurons in the human hippocampus
The hippocampus is essential for episodic memory, yet its coding mechanism remains debated. In humans, two main theories have been proposed: one suggests that concept neurons represent specific elemen...
www.cell.com
March 5, 2025 at 5:43 PM
Reposted by Mattias Petter Johansson (MPJ)
Can what you eat change your mind? 🍎
My first piece in @theguardian.com on why we like what we like, and the role the gut might play in mental health. Hint: it’s probably not all about the microbiome.
January 6, 2025 at 10:46 AM
I find it so lovely that @augmentcode.com
uses the separate domain name hkjl.ai for their @neovim.io
integration 💛💛💛 much poise #neovim
Vim and Neovim developers can now get Augment’s powerful code completions and chat–yes, chat!–right in their editors.

Get started: hjkl.ai
March 6, 2025 at 7:57 AM
This beautiful video by Kurtzgesagt voiced by @johngreensbluesky.bsky.social captures well why I like following the Green brothers. LFG in an orderly fashion.
www.youtube.com/watch?v=GFLb...
This Disease is Deadlier Than The Plague
YouTube video by Kurzgesagt – In a Nutshell
www.youtube.com
March 6, 2025 at 7:14 AM
but the bitcoin can be hacked at any time
Who amongst us has not accidentally sent $81 trillion when you only meant to send $280
February 28, 2025 at 4:23 PM
Reposted by Mattias Petter Johansson (MPJ)
If you're curious about coding-assisted platforms (but tired of the hype and unfulfilled promises), have a look at this video about Augment Code. Maybe, just maybe, this is for you :) #aifordevs #aicoding
youtu.be/LEOSWYlQyVw?...
From Physics to AI: Building a 200ms Coding Assistant | ft. Guy Gur-Ari, co-founder of Augment Code
YouTube video by Fun Fun Function
youtu.be
February 24, 2025 at 6:00 PM
How many % of the currently experienced value of large language models come from the fact that they ingest in a way that a traditional search engines would have been sued and blocked to oblivion if they did? And how expensive would they be if they paid fairly for the privilege?
Every major UK newspaper - left, right, broadsheet, tabloid - is running a front page campaign against copyright carveouts for AI training.

I can't remember the last time any political cause had such broad support, let alone one so anti-big tech and so economically consequential.
February 25, 2025 at 11:57 AM