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jordibc

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Your friendly neighborhood astrophysicist.

Personal website: https://metamagical.org/

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Clojure is a fantastic language, but I have always missed a quick interactive shell where you can easily explore the language, using tab-completion and viewing the documentation easily in a way similar to ipython for the Python world. This release of Babashka fills beautifully that role for me.

I hope it shows and helps others start exploring with this beautiful language!

Writerdeck.org 8 months ago

I thought about it when I read Charlie Stross getting one last year [0]. Then thought, what is essential about it? And decided to try something related, even if it was likely to be just another distraction:

  (defun full-screen ()
    (interactive)
    (shell-command "wmctrl -r :ACTIVE: -btoggle,fullscreen")
    (menu-bar-mode 0))

  (defun just-write ()
    "Convert into a big, clean, centered window."
    (interactive)
    (full-screen) (olivetti-mode) (text-scale-adjust 2) (scroll-bar-mode -1)
    (end-of-buffer) (recenter-top-bottom 0))
This is the simple "just-write" function I wrote in emacs, and it also needs the olivetti package and the wmctrl program.

To my surprise, it actually did the trick. I've written more and more pleasantly since then. I feel it's better than if I had gotten a Writer Deck or similar. So I thought I'd share in case it does the trick for anyone else.

(I also use a font and a color scheme that pleases me, but that's minor.)

[0] https://www.antipope.org/charlie/blog-static/2024/09/zen-and...

I found myself in a similar situation and also started de-googling, which is much nicer and liberating than I was fearing.

I did the exact same thing with Immich (what a great software, by the way!).

And in case it helps:

Instead of always relying on google maps, I now mostly use CoMaps (https://www.comaps.app/). Way better than using directly OpenStreetMap. And for my Pixel 7, I switched to LineageOS with gapps (https://lineageos.org/) and I'm not missing anything and am very happy with it.

Also, I'm trying now Nextcloud (https://nextcloud.com/), with a setup similar to Immich, and now I do believe there is life beyond google, and it's a better life.

Thanks for clarifying! FWIW, I wasn't there, but that matches exactly what I remember from that time (I did follow all the different renamings in detail).

Just to give a brief answer to those reasonable criticisms:

The mixed-grade already exists in complex numbers (it is very useful there, and even more so in geometric algebra).

Differential forms are included in geometric algebra (the exterior/outer products are isomorphic). Turns out, combining that product with the inner product gives you an invertible product (as Clifford found out). That by itself already is a huge advantage.

Finally, Maxwell's equations are sweetly summarized in differential forms, but even more in geometric algebra: dF = J . Not only it is just one equation instead of two, but in addition the "d" (or "nabla") is directly invertible thanks to the geometric product (which differential forms lack and then have to use more indirect methods, including the Hodge dual).

By the way, I'm very partial to geometric algebra, but wouldn't say it is an "error" not to use it! Maybe just a big missed opportunity :)

(I just wish I understood what in meant in "Effective Programs" by "typos are not important". They are, aren't they ? A typo is a runtime error begging to occur during the demo, how is that "not important" ? Never mind.)

They are going to create an error that you can see and fix immediately, in the vast majority of cases. Certainly in compiled languages (like clojure), but less so in interpreted languages like python, where a misspelled variable in a hidden part of the code may not cause an exception until that part of the code is run.

At least, that's my understanding of what he means by typos being less important than other types of mistakes.

By the way, when I saw his comment originally I was surprised too. But when comparing to the other kind of mistakes he talks about I realized that, yes, I'd rather have a typo than any of the other problems! Though of course, I'd prefer to have none :)

jq 1.7 3 years ago

I really like jq, but I think there is at least one nice alternative to it: jet [1].

It is also a single executable, written in clojure and fast. Among other niceties, you don't have to learn any DSL in this case -- at least not if you already know clojure!

[1] https://github.com/borkdude/jet

I encrypt with gpg and upload the .xkdb file (itself already encrypted) to a server I have access to with scp.

Not manually, and not only for this file: this is a system I have to sync the files I want in different machines, by running a little program I wrote (https://gitlab.com/jordibc/csync just in case). I would use syncthing otherwise, but this system has several advantages for me.

If I hadn't access to an online server, I'd use some cloud storage for the same thing.

In case it helps:

In addition to "Geometric Algebra for Physicists" (whose first two chapters I'd recommend to get a nice overview), I found Hestenes' "New Foundations for Classical Mechanics" to be very good and readable.

Also, there are many good resources in https://bivector.net/ , including videos, papers, presentations and programs.

Finally, an interesting paper (that got me kickstarted) is "Imaginary Numbers Are Not Real—The Geometric Algebra of Spacetime" by Gull, Lasenby and Doran.

For sure I got significantly(?) better with classics like Spivak, Apostol, Rudin.

"Real and Complex Analysis" by Rudin, and the two books both named "Calculus" from Spivak and Apostol. But also from Apostol his more concise and far-reaching "Mathematical Analysis". And from Spivak his small gem "Calculus On Manifolds" made quite a dent on me.

Other than more "classic math" books, I also wanted to mention two outliers that I found eye-opening and generally awesome:

* Street-Fighting Mathematics, by Mahajan (http://streetfightingmath.com/). Intuitive, useful and fun.

* Geometric Algebra for Physicists, by Doran and Lasenby. I found the power and elegance of geometric algebra mesmerizing, and even if this book is also about physics and there may be more appropriate math-only books about geometric algebra, this is the one that made it for me.

Xsnow 5 years ago

Apologies to my old classmates at the university, when during the computer lab sessions I would telnet(!) to their machines and launch at random times xneko and/or xsnow. Seeing their surprised and puzzled reactions from a few rows behind was one of the best silly laughs I've had in my life!

(If you happen to be one of them, track me down, I'm thanking you for your inadvertent participation and will invite you to a well-deserved nice meal.)