Grant McDermott
@gmcd.bsky.social
Economics and data science | Former academic now working in the tech sector | Views my own | 🇿🇦 in 🇺🇸 | https://grantmcdermott.com/
Social media (often, very deservedly) gets a bad wrap. But then you also get Thomas Lumley popping into your replies with stats advice, so swings and roundabouts.
January 17, 2026 at 5:12 AM
Social media (often, very deservedly) gets a bad wrap. But then you also get Thomas Lumley popping into your replies with stats advice, so swings and roundabouts.
Relatedly: I recently read about the Burning of Smyrna and, amidst the horror of the fire and casualties, my overriding feeling was one of sadness at the city that was lost. As in, it sounds exactly like somewhere I would want to live.
January 17, 2026 at 5:09 AM
Relatedly: I recently read about the Burning of Smyrna and, amidst the horror of the fire and casualties, my overriding feeling was one of sadness at the city that was lost. As in, it sounds exactly like somewhere I would want to live.
1000% and something that I truly, deeply miss about Cape Town. (Among many things.)
The violent desire for cultural uniformity is just so alien for me at a personal level.
The violent desire for cultural uniformity is just so alien for me at a personal level.
January 17, 2026 at 5:06 AM
1000% and something that I truly, deeply miss about Cape Town. (Among many things.)
The violent desire for cultural uniformity is just so alien for me at a personal level.
The violent desire for cultural uniformity is just so alien for me at a personal level.
Lololol. It's such a cringe tell, right?
January 14, 2026 at 4:24 PM
Lololol. It's such a cringe tell, right?
Real pros use the ln -sn flag(s)
;-)
But ya, symlinks are super useful and a good habit to get into.
;-)
But ya, symlinks are super useful and a good habit to get into.
January 13, 2026 at 10:21 PM
Real pros use the ln -sn flag(s)
;-)
But ya, symlinks are super useful and a good habit to get into.
;-)
But ya, symlinks are super useful and a good habit to get into.
Nice. Using existing guides are great ofc, but I do think there's value in getting an AI to extract the (implicit) patterns of your own code.
January 13, 2026 at 10:17 PM
Nice. Using existing guides are great ofc, but I do think there's value in getting an AI to extract the (implicit) patterns of your own code.
At work we use VS Code or derivatives (Positron / Kiro). But I most often pair directly with the terminal TBH.
Start with $20 and see how you go ;-)
Start with $20 and see how you go ;-)
January 13, 2026 at 10:15 PM
At work we use VS Code or derivatives (Positron / Kiro). But I most often pair directly with the terminal TBH.
Start with $20 and see how you go ;-)
Start with $20 and see how you go ;-)
@vincentab.bsky.social can keep me honest here, but I'm pretty sure you can do something like:
library(marginaleffects)
mod = lm(mpg ~ wt + hp + cyl, mtcars)
mod |>
hypotheses(mod, "wt >= hp", "hp >= cyl") |>
hypotheses(joint = TRUE)
marginaleffects.com/bonus/hypoth...
library(marginaleffects)
mod = lm(mpg ~ wt + hp + cyl, mtcars)
mod |>
hypotheses(mod, "wt >= hp", "hp >= cyl") |>
hypotheses(joint = TRUE)
marginaleffects.com/bonus/hypoth...
January 13, 2026 at 10:12 PM
@vincentab.bsky.social can keep me honest here, but I'm pretty sure you can do something like:
library(marginaleffects)
mod = lm(mpg ~ wt + hp + cyl, mtcars)
mod |>
hypotheses(mod, "wt >= hp", "hp >= cyl") |>
hypotheses(joint = TRUE)
marginaleffects.com/bonus/hypoth...
library(marginaleffects)
mod = lm(mpg ~ wt + hp + cyl, mtcars)
mod |>
hypotheses(mod, "wt >= hp", "hp >= cyl") |>
hypotheses(joint = TRUE)
marginaleffects.com/bonus/hypoth...
The whole game here is furnishing relevant & specific context to your AI, w/out overwhelming. (A bias-variance tradeoff of a kind.)
If AI knows that you always use Oxford commas or load ggplot2 in every project, then this improves consistency & reliability, leading to an overall better experience.
If AI knows that you always use Oxford commas or load ggplot2 in every project, then this improves consistency & reliability, leading to an overall better experience.
January 12, 2026 at 9:24 PM
The whole game here is furnishing relevant & specific context to your AI, w/out overwhelming. (A bias-variance tradeoff of a kind.)
If AI knows that you always use Oxford commas or load ggplot2 in every project, then this improves consistency & reliability, leading to an overall better experience.
If AI knows that you always use Oxford commas or load ggplot2 in every project, then this improves consistency & reliability, leading to an overall better experience.
This will take 1 or 2 minutes at most, and give you a starter template that you can use to save a lot of boilerplate time down the road. Spend a bit more time iterating on the .md (think of it as a living document) and you'll have an invaluable pair programmer/writer who is much more attuned to you.
January 12, 2026 at 9:18 PM
This will take 1 or 2 minutes at most, and give you a starter template that you can use to save a lot of boilerplate time down the road. Spend a bit more time iterating on the .md (think of it as a living document) and you'll have an invaluable pair programmer/writer who is much more attuned to you.
Jeez. Just when you think these goons have reached the bottom of the intellectual barrel...
January 12, 2026 at 9:00 PM
Jeez. Just when you think these goons have reached the bottom of the intellectual barrel...
Including some recently updated slides since I gave a talk at the Bank of Portugal in December... speaking of which, I also gave a shout out to you for the Julia version. Doesn't look like the videos are up yet but should be there soon? github.com/BPLIM/Worksh...
Workshops/BPLIM2025 at master · BPLIM/Workshops
Collection of presentations at BPLIM's workshops. Contribute to BPLIM/Workshops development by creating an account on GitHub.
github.com
January 12, 2026 at 8:57 PM
Including some recently updated slides since I gave a talk at the Bank of Portugal in December... speaking of which, I also gave a shout out to you for the Julia version. Doesn't look like the videos are up yet but should be there soon? github.com/BPLIM/Worksh...
... the extent that these new implementations "work", it's largely by piggy backing of an existing SW / test suite, written by someone who actually knew (knows) what they were doing.
Maybe it's helpful to have XYZ estimator re-written in Rust (TM) idk. But there's very discipline to back it up.
Maybe it's helpful to have XYZ estimator re-written in Rust (TM) idk. But there's very discipline to back it up.
January 7, 2026 at 10:52 PM
... the extent that these new implementations "work", it's largely by piggy backing of an existing SW / test suite, written by someone who actually knew (knows) what they were doing.
Maybe it's helpful to have XYZ estimator re-written in Rust (TM) idk. But there's very discipline to back it up.
Maybe it's helpful to have XYZ estimator re-written in Rust (TM) idk. But there's very discipline to back it up.
Yeah, exactly. It's turtles all the way down.
Fwiw, I don't mean to sound nihilistic, but I am at a weird inflection point. Personally, I feel like I'm getting a *ton* of value from pair programming. But I'm increasingly seeing vibe-coded semi slop in my domain (metrics + stats packages). To [1/2]
Fwiw, I don't mean to sound nihilistic, but I am at a weird inflection point. Personally, I feel like I'm getting a *ton* of value from pair programming. But I'm increasingly seeing vibe-coded semi slop in my domain (metrics + stats packages). To [1/2]
January 7, 2026 at 10:47 PM
Yeah, exactly. It's turtles all the way down.
Fwiw, I don't mean to sound nihilistic, but I am at a weird inflection point. Personally, I feel like I'm getting a *ton* of value from pair programming. But I'm increasingly seeing vibe-coded semi slop in my domain (metrics + stats packages). To [1/2]
Fwiw, I don't mean to sound nihilistic, but I am at a weird inflection point. Personally, I feel like I'm getting a *ton* of value from pair programming. But I'm increasingly seeing vibe-coded semi slop in my domain (metrics + stats packages). To [1/2]
Counterpoint: A shibboleth of yolo vibe coding is a battery of (shitty to mid) tests.
January 7, 2026 at 10:16 PM
Counterpoint: A shibboleth of yolo vibe coding is a battery of (shitty to mid) tests.
An overlooked point IMO is that the Xitter algo was rubbish even before all of Musk's self-aggrandizing, ketamine-fueled bullshit. I'd like to click on an occasional post or profile for pure curiosity's sake, without my feed being Busta Rhymes yo dawged into a singular thread from that person.
December 24, 2025 at 8:46 PM
An overlooked point IMO is that the Xitter algo was rubbish even before all of Musk's self-aggrandizing, ketamine-fueled bullshit. I'd like to click on an occasional post or profile for pure curiosity's sake, without my feed being Busta Rhymes yo dawged into a singular thread from that person.
Art.
(I cannot be the only person who would willingly shell out real money for a compendium of KJ Healy's greatest poasts / twetes.)
(I cannot be the only person who would willingly shell out real money for a compendium of KJ Healy's greatest poasts / twetes.)
December 24, 2025 at 8:17 PM
Art.
(I cannot be the only person who would willingly shell out real money for a compendium of KJ Healy's greatest poasts / twetes.)
(I cannot be the only person who would willingly shell out real money for a compendium of KJ Healy's greatest poasts / twetes.)
+1 although this is the incoming PR I'm most excited about. github.com/Rdatatable/d...
modularize optimization internals by ben-schwen · Pull Request #7401 · Rdatatable/data.table
Closes Using Map instead of lapply turns GForce off #5336
Closes lapply GForce opt could work also without .SD #5032
Closes Move GForce tests to own script #4305
Towards GForce optimisation coul...
github.com
December 24, 2025 at 8:10 PM
+1 although this is the incoming PR I'm most excited about. github.com/Rdatatable/d...
Exactly!
I use the word "persona" b/c that's how I think of it. And you can v. easily switch between different personas in the same session depending on your needs (programming language, research mode, referee/reviewer, etc.)
www.claude.com/blog/extendi...
I use the word "persona" b/c that's how I think of it. And you can v. easily switch between different personas in the same session depending on your needs (programming language, research mode, referee/reviewer, etc.)
www.claude.com/blog/extendi...
Extending Claude's capabilities with skills and MCP | Claude
Learn how skills and MCP work together to build agents that follow your workflows and use external tools effectively. Best practices and real-world examples.
www.claude.com
December 24, 2025 at 5:27 PM
Exactly!
I use the word "persona" b/c that's how I think of it. And you can v. easily switch between different personas in the same session depending on your needs (programming language, research mode, referee/reviewer, etc.)
www.claude.com/blog/extendi...
I use the word "persona" b/c that's how I think of it. And you can v. easily switch between different personas in the same session depending on your needs (programming language, research mode, referee/reviewer, etc.)
www.claude.com/blog/extendi...
... I also combine skills w/ MCPs. I think this is more or less what your superpower link is doing, but w/ more customization/control. E.g. My "r-expert" skill (persona) knows about the `btw` package and how to use these tools to read up on documentation, inspect objects in my active R session, etc.
December 24, 2025 at 5:24 PM
... I also combine skills w/ MCPs. I think this is more or less what your superpower link is doing, but w/ more customization/control. E.g. My "r-expert" skill (persona) knows about the `btw` package and how to use these tools to read up on documentation, inspect objects in my active R session, etc.