You know how you slip once on a habit and everything goes crazy? Well, I’ve been 4 weeks without writing these, so here’s the accumulated reading from 4 weeks. Because, even if I don’t write it, I read a lot anyway. Also, there’s lot of interesting content this “week”.
I had always wanted to play with Processing (after leafing through The
some years ago). My general dislike for Java or the JVM made me just play a
short amount of time with processing.js something around 2011 (there was a
native processing.js application for iOS, I used it for a while on my iPad and
A few weeks ago I started trying a pre-beta release of Dyalog APL (now available as “full beta”) for Mac. Fellow Mac users, looks like we are in for a treat after so much time of only having GNU APL and the pretty expensive APLX. Now Mac APL lovers, users and aficionados will have a competitive, commercial option. At last!
I started with the usual 1+1, ⍳ 10 , ⍴ ⍳ 10 to check it worked as expected.
Is this line noise?
⍉' *'[⍎'1+0<|z',(∊150⍴⊂'←c+m×m'),'←c←(¯2.1J¯1.3+(((2.6÷b-1)×(¯1+⍳b))∘.+(0J1×(2.6÷b-1)×(¯1+⍳b←51))))'] Nope. This is not line noise, but a complete APL program to display the Mandelbrot set in glorious ASCII, with asterisks and spaces just like Brooks and Matelski did a long time ago while studying Kleinian groups (it’s a short paper, read it someday). I’ll explain in (a lot, I hope) detail this line in a few moments. So, what’s APL first?
Click to open in a new window/tab and then right click to Save as
Today is Iceland’s National Day (commemorating their independence day and the date of birth of Jón Sigurðsson), and to commemorate it I share this image with everyone.
I computed this image a long, long time ago (using the Distance Estimator Method, paralellised with PVM using 16 computers, it took just 2 minutes). The full file is a 30MB pdf, which I printed large-size, and sits in my office.
A week without writing here. A week with little thesis related work done. But it has also been a week with ideas and things and such. You know, two weeks ago I was in Dresden for a conference. Lots of parallel sessions, and quite a few time to think. This post is mostly a digest from my life bookmarks for these two weeks.
Several complex dynamic ideas: Unrelated to my thesis, but I’ve been thinking about them these days.
As you may remember, I spent quite some time this August with Lavaurs algorithm for the topological identification of the circle corresponding to the Mandelbrot set. After that, I spent quite some more trying to do pictures of external rays to show side by side. I was not able… and then found Mandel.
Thanks to Mandel, LISP and my Lavaurs code
Really nice program, with lots and lots of options (and I met the programmer, which happens to be also mathematician, we met at a conference).
As you may already know, I presented a poster at a conference recently, and did the set up with Scribus, the texts with LaTeX with the Beamer and Beamerposter packages.
Note from 2019: I can’t find the final version of that poster, only a modified version from a few months later for another conference.
The first piece of advise, is to set page guides where needed (in the Page menu, you can put them at a certain numerical place, and then move them along) and then Snap to guides in the same menu.
I have several (really, a lot) of programs to compute different images for my article, amusement, anything. And all of them require a change-and-try approach for zooming. The first I wrote needed to be finished quickly… so I just hard-coded in the source the parameters. And this program turned to be the basis for all others… And now each zoom requires some calculations and recompile.
A time ago I decided to do something about it.
Just 5 excerpts of it
And “e” appears from nowhere!9 programming books I have read and somewhat liked…
C code juicer: detecting copied programming assignments
Cron, diff & wget: Watch changes in a webpage
8 reasons for re-inventing the wheel as a programmer
Approximating images with randomly placed translucent triangles
September is to months as Monday is to weekdays
September is again here, like a new year in more than a sense. I have no new “New Year’s promises”, since the beginning of the year. In fact, most of the things I wanted to do are already done, on the way to be done or I gave up. Well, let’s summarize what I shall do these three months to end 2009
These days I’ve been busy programming a version of Lavaurs algorithm for the idenfication of circle chords: the abstract Mandelbrot set.
The images don’t look like much, but the output of the program is nicer: it outputs an Encapsulated PostScript file which looks sharper. But when converting to png with ImageMagick some distortion appeared.
Lavaurs chords, depth 13 cutoff
Lavaurs chords, depth 5
Lavaurs chords, depth 13
Lavaurs algorithm on course
Like almost every year, August comes with a lot of pending To Do lists… This year, it is choking full, mostly of work related issues, and some unknotted threads waiting to be finished. And in two and a half weeks I’ll head for Paris, and then my “vacation” is over.
Yesterday I wasted my morning: bought my orange belt, set up the external monitor for my netbook, configured the printer, fotocopied two pages of a book and drank an horchata with a friend.
As I already did with Douady Rabbits, here is another dynamical plane, this time corresponding to a Siegel disk in an entire transcendental family in a parameter corresponding to a polynomial-like region.
Siegel disk in an ETF, available below as wallpaper
Siegel disk for desktop background 1280x800
Siegel disk for desktop background 1024x768
You can also buy a poster version here.
If you liked it, or have whatever else to say please leave a comment, digg, stumble or whatever you feel like doing.
I have been experimenting with exponential-power potentials in my fractal images as of late, and by far the best results have been these. You can download it as a desktop wallpaper, hope you enjoy it. This Douady rabbit appears as a capture zone for a critical value in an exponential family.
Douady rabbit in an exponential family, available below as wallpaper
Douady rabbit for desktop background 1280x800
Douady rabbit for desktop background 1024x768