An ag(e)ing hacker

Luca Saiu's blog

Post index (17 posts)
Atom feed for all posts All post feeds: Atom 1.0, RSS 2.0.
Happy pi Approximation Day 20142014-07-22 00:10
Updated: 2015-01-23 22:59
It’s 22/7 again. Last year on pi Approximation Day I published a simple Forth program based on an intuitive geometrical idea: see Happy pi approximation day 2013 (<>). I’ve been thinking about what to do in 2014 for some time, without finding anything as nice from the programming point of view. Sure, you can find series and continued fractions converging to pi, even rapidly; these methods work, but the corresponding programs are trivial to code and don’t provide any insight. So I chose another route: a practical experiment to approximate pi by cutting and weighing metal. The result turned out [...] Read more
Tags: english, experiment, gnu, guile, hacking, pi, science

A practical GNU epsilon tutorial2013-08-23 12:54
Updated: 2013-12-27 19:39
A practical GNU epsilon tutorial Audience Lexical conventions Rationale and introduction My PhD thesis Implementation, and the relation beteen epsilon0 and epsilon1 The bootstrap problem Setup Writing more comfortably, from ‘guile+whatever’ and Emacs Basics of epsilon1 The stuff values are made of: fixnums, pointers, buffers Error situations in epsilon1 Slightly higher-level data structures: vectors, strings, boxes, tuples, records Equality and boxedness tags Lists, and simple programming examples Digression: a look at epsilon0 Practical programming in epsilon1 Sums A programming example: structural equality with boxedness tags A look at reflective data structures ‘e1:define’ is just a macro! S-expressions What’s the point [...] Read more
Tags: english, epsilon, gnu, guile, hacking, tutorial

Hello from the GHM2013-08-22 16:13
Updated: 2013-08-31 21:15
Posting during a quiet time at the GHM pre-meeting, before most people arrive. We have something new to show: [ghm-t-shirt] I went to get the t-shirt at the shop this morning, with José; they did a nice job in the end. This post is just for bragging a little, and to make the people who aren’t here envious. — Luca Saiu, 2013-08-22 16:13 (last update: 2013-08-31 21:15) [...] Read more
Tags: english, gnu, hacking

Playing with graphics2013-08-12 02:40
Updated: 2015-01-26 19:43
I’m not good at graphics. Or rather, don’t think I have particularly good taste. Now that I’m thinking of it, in the remote past as part of my first big job I was actually paid to do photo touch-ups. It was my driving school job. Old graphic hacks The screenshot below belongs to that project; what we would call now an e-learning system, to be used locally on the driving school computers. [a simple touch up I did] The driving school owner went around taking photos of the roads in the neighborhood, so that his customers could recognize familiar places, [...] Read more
Tags: english, gimp, gnu, graphics, hacking

Privacy 2013: Why. When. How --- a talk by Werner Koch2013-08-05 23:05
Updated: 2013-08-26 12:16
A couple days ago Sylvain (<>) asked me to proofread his transcription of the latest talk by Werner Koch (<>). That was an occasion for listening carefully to what Werner has to say about electronic communication privacy in the global police state. Following his speech while paying attention to the text was instructive for me and, I think, a good use of my time. Werner is very competent on the subject: he’s a security expert and, as you probably know, the main author of GPG (<>). [Werner Koch speaking] Werner speaking: a frame from the video, CC-BY-SA <>. I’ve known [...] Read more
Tags: english, gnu, politics, privacy, security, talk

Happy pi approximation day 20132013-07-21 12:34
Updated: 2014-07-21 21:14
The fraction 22/7 has been known since antiquity as a simple rational approximation of pi. The fraction decimal expansion is 3.(142857); since pi is about 3.141592653589793, the approximation has three correct digits. Of course nowadays we can compute much better approximations with computers, and billions of digits are known: <π> is a nice review also explaining some efficient computation methods. For example if you want to obtain a lot of pi digits in a short time you may like the series by Ramanujan, yielding very good approximations even with a small number of terms; but that’s not the point now. [...] Read more
Tags: forth, gnu, hacking, pi, tutorial

GNU Hackers Meeting 2013 in Paris, France2013-05-17 20:39
Updated: 2013-10-10 21:36
Thanks to a kind offer by Sylvestre Ledru (<>) from IRILL (<>) we have a venue for this year’s GNU Hackers Meeting: we will be in Paris, France, for the second time at IRILL after the very successful 2011 edition. Since I live near Paris and I also happen to work at IRILL once or twice a week I’ve decided to do something to help organize the event, along with Sylvestre and Dodji Seketeli (<>) who graciously volunteered as well. The meeting will take place in late August 2013: right now we’re deciding whether to have talks on Friday 23 [...] Read more
Tags: english, ghm, gnu, hacking, paris

European unitary patent amendments2012-12-10 13:17
Updated: 2012-12-11 19:40
Please call the Members of the European Parliament right now, asking them to support amendments 74 and 76 on the Unitary Patent directive. <> • Amendment 74 restates that software is not patentable, as already expressed by the European Parliament in 2003 and 2005; • amendment 76 makes explicit the legislator’s control, in particular the European Parliament’s. Without this amendment the European Patent Office would not be accountable to enforce any limit on patentability, thus opening the door to unlimited US-style patenting of abstract ideas including pure software. All amendments, including 74 and 76: <> The plenary vote will take [...] Read more
Tags: english, europe, gnu, politics, software-patents

Meta-update and GNU epsilon news2012-08-29 23:33
Updated: 2012-09-16 13:38
This little diary of mine needed some love. A good excuse to motivate myself to write more often comes from the idea of syndication in the GNU Planet (<>); to make that possible without adding off-topic stuff to the GNU site I’ve recently improved trivalblog to also support per-tag RSS and Atom feeds — the idea being, of course, to have only posts explicitly tagged as “gnu” linked from the planet. My little blog system is described in The trivialblog software (<>). It’s just a quick unpolished hack with no documentation built upon bash and Texinfo, but I find it [...] Read more
Tags: english, epsilon, gnu, hacking, meta

ACTA as a test for democracy in Europe2012-02-11 02:01
Updated: 2012-02-14 13:27
The conflict couldn’t be more clear. On one side you have the copyright and patent lobbies pushing for even more draconian measures against private behavior, more limitations to freedom of expression, and more power for them on top of what they already have in this war of the rich against the poor. On the other side, of course, there is the public interest. Seeing what the European Parliament does on this occasion will be a test of its worth: will another European institution bend to the pressure of rich lobbies, or will it respect its democratic mandate? Will it prove [...] Read more
Tags: acta, censorship, english, politics

I will remember John McCarthy2011-10-25 23:55
Updated: 2014-07-26 14:57
I’ve just learned that Professor John McCarthy (<>) died two days ago on October 23, at the age of 84. He was the father of Lisp, Artificial Intelligence, Non-Monotonic Logics and Situation Calculus; and garbage collection, and time-sharing. An amusingly absent-minded brilliant mathematician and thinker with philosophical inclinations, and a technological optimist. I’ve loved reading his lightly sketched deep thoughts in his plain unassuming style(1), so different from the pretentious generations of big-egoed Lispers who came after him, myself included. And who even cares now if I agree with what he said one hundred percent, or not; I’ve never met [...] Read more
Tags: computer-science, english, my-masters, obituaries, parentheses

About Erdős numbers and not wanting what you have2011-09-22 19:41
Updated: 2015-09-15 15:54
Today at lunch with colleagues(1) we were having a very nice, relaxed conversation. At some point somebody mentioned he knew somebody who knew Erdős (<>); so I asked him what his Erdős number (<>) was, and he said it. Then —I think for the first time— the thought crossed my mind that I also could already have a finite Erdős number. I’ve just found that in fact that’s the case, and has been for several years now. My Erdős number is(2) at most 6. For example: • Paul Erdős (0) • Vilmos Komornik (1) • Marco Pedicini (2) • Patrick [...] Read more
Tags: english, identity, myself, research, university

How I learned procedural abstraction and the wonder of science2011-09-19 05:06
Updated: 2014-11-24 23:55
Inspired by a happy “discovery” I made today, I’ve written this instead of finishing the post about identity. The abandoned tape This story began on a summer evening of the late Eighties when I was 10, maybe 11. I was at some small country fair near home with my brother, five years younger than me — quite a big difference back then. My brother found an audio cassette discarded on the ground, and wanted to take it home; it looked dirty and I remember that I didn’t want to pick it up at first, but I guess I wasn’t too [...] Read more
Tags: commodore-64, english, hacking, my-masters, myself, nostalgia, science

Things to come2011-09-16 15:03
Updated: 2011-11-02 04:41
I’ve seen from the server log that some people are looking for updates (thanks!). Since the post I’m writing now is not over yet, let me give you just an idea of what I think I will add soon: • Against identity — about the conflict between identity and culture, if you will. This will touch nationalism, sports fans, politics and religion. • The World-Wide Web and the fun of programming — Since its writing I softened a little the language of the first post: there I attacked the web, in the first version quite violently; but before using strong [...] Read more
Tags: english, meta

Writing every day2011-09-09 01:50
Updated: 2011-09-12 08:00
I’ve been remembering the Latin phrase Nulla dies sine linea (no day [shall pass] without [writing] a line) for years now. Until a couple of minutes ago I was sure it was a motto by Gabriele d’Annunzio(1) (1863-1938), who despite the sheer beauty of some of his prose and poetry was quite revolting as a person — the kind of artist that you cannot quite declare you admire without adding all sorts of qualifiers and disclaimers. Annoying but necessary. You know, it’s about your reputation, and here I’m not kidding: that guy was a lot worse than just a histrionic [...] Read more
Tags: d-annunzio, english, latin, meta, myself, very-bad-literature

The trivialblog software2011-09-08 08:45
Updated: 2011-09-08 14:44
I’ve written the software running this blog myself, in Bash; in fact it’s mostly a simple combination of GNU command-line utilities, producing completely static HTML. Texinfo renders the post source text into HTML; my scripts generate indices, links and other minor things. I will probably add a PDF export feature later. I’ve put together the software very quickly, for myself; the source is crude and there’s no documentation, but since I guess somebody might want a copy anyway I’m publicly releasing it. trivialblog is free software, released under the GNU GPL version 3 or later. Most icons were not drawn [...] Read more
Tags: english, gnu, hacking, meta, software-by-myself

About this blog2011-09-08 08:44
Updated: 2011-09-20 04:24
I have rough ideas about what I’d want to write about, but I don’t really know with what frequency I will touch each topic. I’m mostly interested in free software, (computer) languages and Computer Science in general, art, literature and politics; but I make no promise of staying on-topic. I will also not be necessarily “balanced”, soft or cautious when expressing my opinions. This is my site (by the way I pay hosting costs myself, with my money) and as such it is the appropriate place for holding my opinions. If you want to engage in discussion with me, there’s [...] Read more
Tags: angle-brackets, english, meta, myself

Post index (17 posts)

Go to the main index...
Atom feed All post feeds: Atom 1.0, RSS 2.0.

[my photo]
Luca Saiu

The opinions I express here are my own and do not necessarily reflect the beliefs or policies of my employer, or for that matter of anyone else. In case you felt that the public statement of my thoughts threatened your warm sense of security and your emotional stability, please feel free to leave at any time.

The system does not support user comments and probably never will. Anyway you can contact me by e-mail if you want to discuss some topic with me. I might update my posts if you provide interesting insights.

Copyright © 2009, 2011, 2012, 2013, 2014 Luca Saiu
Verbatim copying and redistribution of this entire page are permitted in any medium without royalties, provided this notice is preserved.
This page was generated by trivialblog. trivialblog is free software, available under the GNU GPL.
Tag icon copyright information is available in this file.