Robert van Engelen, PhD
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engelen.bsky.social
Robert van Engelen, PhD
@engelen.bsky.social
Possessed by math and coding since the 80s, vintage tech enthusiast, steam engines fanatic, CEO/CTO of Genivia, fmr Professor of Computer Science and Scientific Computing | NYC | 🇺🇸🇳🇱 | defend democracy | support 🇺🇦 | please be kind to animals🙏
I’ve written code with SWI-Prolog since 1994, so it’s certainly over 30 years. Jan came over to our Uni when I had invited him to give a talk. Glad he also added multi-precision integers later, like I added myself using the GNU MP lib, stored as atoms. The foreign interface was very useful.
December 5, 2025 at 7:54 PM
SWI-Prolog is excellent. The author, Jan Wielemaker, keeps expanding it to a does-it-all Prolog platform.
December 5, 2025 at 7:30 PM
The author admits in the article that numerical weather forecast models are still needed. Numerical models use physics (PDE math etc). But AI is a black box, trained with historical data to extrapolate a prediction. AI is not robust and will make mistakes when measurements do not align with history.
November 27, 2025 at 1:15 PM
Weather balloons are largely unnecessary. We have excellent weather models that are fed land-based data and sea-based data. So I’m so disappointed in IEEE to publish this unscientific article claiming that AI and weather balloons are better. spectrum.ieee.org/amp/ai-weath...
Inside the Best Weather-Forecasting AI in the World
Autonomous weather balloons surf the winds to collect needed data
spectrum.ieee.org
November 27, 2025 at 1:00 PM
💔
November 22, 2025 at 5:29 PM
Naïve implementation that runs in quadratic time, so won’t scale. Instead of that, use a sliding window and update the sum incrementally (subtract outgoing, add incoming). Use C++ for speed.
November 14, 2025 at 1:19 PM
Addicted? Nah. Just always close to grab, like these on our counter right now.
November 1, 2025 at 11:48 AM
Philips MSX New Media System
October 17, 2025 at 4:59 PM
-1 1 RSHIFT . since RSHIFT is a logical shift, not arithmetic, it shifts in a 0 so to get max positive value of a signed integer. Minor caveat: Assumes 2s complement, but which is universal these days.
October 2, 2025 at 9:27 AM
Hope this helps: I wrote a Forth introduction and manual for newbies to Forth, for a 2012 standard Forth implementation which is more up to date than the vintage textbook introductions github.com/Robert-van-E...
github.com
September 26, 2025 at 7:13 PM
Combinations of words are included for performance, such as 1+ 2* 2/ 0= to perform two sequential operations with one word, but there are also a few to perform two operations simultaneously like /MOD (div mod) to return two results. Because most vintage Forth do not optimize code, these are useful.
September 26, 2025 at 6:41 PM