Mike X Cohen PhD, Sincxpress Education
@mikexcohen.bsky.social
Check out my longer posts on Substack (mostly detailed tutorials about data science and LLMs). mikexcohen.substack.com Explore my video-based courses and books ➔ sincxpress.com
I nerded out and wrote a Substack post on Givens angles and Jacobi rotations. It's a tutorial post with Python code to demonstrate everything. By the end of the post, you will accidentally discover the eigenvalues of a matrix. It's fun. mikexcohen.substack.com/p/givens-ang...
Givens angle, Jacobi rotations, and eigenvalues
Join me for a meander down linear-algebra lane
mikexcohen.substack.com
Fun movie idea: Time travel exists but you can only travel to the year 6174. mikexcohen.substack.com/p/a-kink-in-...
A kink in the universe at 6174
I’m gonna do something different: I’m not going to talk about AI.
mikexcohen.substack.com
Are you a neuroscientist considering a transition to AI? I wrote some thoughts about it. mikexcohen.substack.com/p/transition...
Transitioning from neuroscience to AI?
Some tips from someone who's done it (sort of)
mikexcohen.substack.com
I'm almost finished my new book, titled "50 ML projects to understand LLMs". I call this figure the "mitten plot."
How to live a happy life, according to the most elegant equation in humanity. (Hint: it's the math version of "omit needless words.") mikexcohen.substack.com/p/eulers-ide...
In my latest substack post, I show how to measure gender bias in open-source LLMs. The post comes with detailed explanations and a Python notebook file that you can easily adapt to any other biases. Curious? Come check it out :) mikexcohen.substack.com/p/gender-bia...
Statistician: Someone who has their head in an oven, their feet in an ice bucket, and says "on average I feel fine."
If I had a million euros (that's 1.170686 million USD), I would do Daily Data Challenges to master machine-learning. Like this one, which involves running a t-test in Python to compare two random samples. Act like a millionaire. Solve Daily Data Challenges. mikexcohen.substack.com/p/ddc-15-two...
DDC-15: Two-samples t-test
A data challenge a day helps you master machine learning
mikexcohen.substack.com
“King – man + woman = queen” sounds smart until you actually check the math. Spoiler: it’s fake news. mikexcohen.substack.com/p/king-man-woman-queen-is-fake-news
"King - man + woman = queen" is fake news
On analogies and arithmetic inside LLM embeddings spaces.
mikexcohen.substack.com
I don't know what's going on in this AI image. But I do know this: Daily Data Challenge #25 is short and very practical for data science. You'll get to create a symmetric matrix and extract its unique elements. Can you solve it in less than 6 minutes? mikexcohen.substack.com/p/ddc-25-uni...
Here’s a picture of Thalorion The Destroyer reading my calculus textbook. I hope he likes it! Otherwise he might unleash doom on humanity. www.amazon.com/dp/B0DX6BPPZ8
Karl Gauss (yeah, *that* Gauss) sent me a fax this morning to say that he really enjoyed working through today's Daily Data Challenge. mikexcohen.substack.com/p/ddc-23-dis...
DDC-23: Distributions of MNIST pixel values
A data challenge a day helps you master machine learning
mikexcohen.substack.com
Why I left academia and neuroscience. This post on Substack has gained a lot of traction. I think many people identify with it. (Most of my posts are technical tutorials on machine-learning and LLM-mechanisms.) mikexcohen.substack.com/p/why-i-left...
Why I left academia and neuroscience
Don't worry, this isn't yet another story of rage-quitting.
mikexcohen.substack.com
Daily Data Challenge 8: Test for Pythagorean triplets A data challenge a day helps you master machine learning. More exercises and solutions at mikexcohen.substack.com youtube.com/shorts/LlqS2...
Daily Data Challenge 8: Test for Pythagorean triplets
YouTube video by Mike X Cohen
youtube.com
Bootstrapping: because sometimes asking “what if?” 10,000 times is a valid math strategy. open.substack.com/pub/mikexcoh...
Confidence intervals 2/3: bootstrapping methods
Learn computational statistics in the second part of this three-part series.
open.substack.com
genAI never fails to deliver the laughs.
Daily Data Challenges are going strong. Today's challenge is to create this beautiful graph using numpy and matplotlib. Can you do it? mikexcohen.substack.com/p/ddc-18-err...
People talk a lot about GPT5 and hallucinations and trust and so on. But let's not forget that GPT2 is the ultimate arbiter of truth and science. Proof of my claim? This zinger from GPT2. Wanna explore GPT2's wisdom in your own private Python session? mikexcohen.substack.com/p/lessons-on...
Dear bluesky neuroscientists: You should pay attention to the field of LLM mechanistic interpretability. Not because LLMs are like real brains (they are absolutely nothing alike), but because mech interp analysis methods would be useful in neuroscience. Start learning here: tinyurl.com/48pum4pb
LLM breakdown 1/6: Tokenization (words to integers)
Large language models can't read; instead, they are given numbers that come from text.
mikexcohen.substack.com
One of my fav quotes: "The way you do anything is the way you do everything." The problem with these pithy faux-philosophical quotes is that they don't stand up to scrutiny. For example, I definitely do not pick my nose with the same rigor, depth, and intensity with which I write 600-page textbooks
Can you code the Fourier transform from scratch? I bet you can. Spend 20 minutes on the Substack post, and you'll learn everything you need to understand and code the FT in Python. mikexcohen.substack.com/p/the-fourie...
Do you have enough confidence? I am, of course, talking about confidence intervals, the statistical measure of uncertainty around a sample characteristic like the average or correlation. Here's my latest series on Substack about confidence intervals: mikexcohen.substack.com/p/confidence...
Confidence intervals 1/3: interpretation and equation
Start building confidence about confidence intervals in the first of this three-part series.
mikexcohen.substack.com
Daily data challenge. 10 minutes a day to improve your coding, data science, and visualization skills. open.substack.com/pub/mikexcoh...
Happy teacher's day (in India)!
