| Andrew Cooke | Contents | Latest | RSS | Twitter | Previous | Next

C[omp]ute

Welcome to my blog, which was once a mailing list of the same name and is still generated by mail. Please reply via the "comment" links.

Always interested in offers/projects/new ideas. Eclectic experience in fields like: numerical computing; Python web; Java enterprise; functional languages; GPGPU; SQL databases; etc. Based in Santiago, Chile; telecommute worldwide. CV; email.

Personal Projects

Lepl parser for Python.

Colorless Green.

Photography around Santiago.

SVG experiment.

Professional Portfolio

Calibration of seismometers.

Data access via web services.

Cache rewrite.

Extending OpenSSH.

C-ORM: docs, API.

Last 100 entries

SFO Get Libor Trader (14 years); Why Are There Still So Many Jobs?; Navier Stokes Incomplete; More on Benford; FBI Claimed Vandalism; Architectural Tessellation; Also: Go, Blake's 7; Delusions of Gender (book); Crypto AG DID work with NSA / GCHQ; UNUMS (Universal Number Format); MOOCs (Massive Open Online Courses); Interesting Looking Game; Euler's Theorem for Polynomials; Weeks 3-6; Reddit Comment; Differential Cryptanalysis For Dummies; Japanese Graphic Design; Books To Be Re-Read; And Today I Learned Bugs Need Clear Examples; Factoring a 67 bit prime in your head; Islamic Geometric Art; Useful Julia Backtraces from Tasks; Nothing, however, is lost with less discomfort than that which, when lost, cannot be missed; Article on Didion; Cost of Living by City; British Slavery; Derrida on Metaphor; African SciFi; Traits in Julia; Alternative Japanese Lit; Pulic Key as Address (Snow); Why Information Grows; The Blindness Of The Chilean Elite; Some Victoriagate Links; This Is Why I Left StackOverflow; New TLS Implementation; Maths for Physicists; How I Am 8; 1000 Word Philosophy; Cyberpunk Reading List; Detailed Discussion of Message Dispatch in ParserCombinator Library for Julia; FizzBuzz in Julia w Dependent Types; kokko - Design Shop in Osaka; Summary of Greece, Currently; LLVM and GPUs; See Also; Schoolgirl Groyps (Maths); Japanese Lit; Another Example - Modular Arithmetic; Music from United; Python 2 and 3 compatible alternative.; Read Agatha Christie for the Plot; A Constructive Look at TempleOS; Music Thread w Many Recommendations; Fixed Version; A Useful Julia Macro To Define Equality And Hash; k3b cdrom access, OpenSuse 13.1; Week 2; From outside, the UK looks less than stellar; Huge Fonts in VirtualBox; Keen - Complex Emergencies; The Fallen of World War II; Some Spanish Fiction; Calling C From Fortran 95; Bjork DJ Set; Z3 Example With Python; Week 1; Useful Guide To Starting With IJulia; UK Election + Media; Review: Reinventing Organizations; Inline Assembly With Julia / LLVM; Against the definition of types; Dumb Crypto Paper; The Search For Quasi-Periodicity...; Is There An Alternative To Processing?; CARDIAC (CARDboard Illustrative Aid to Computation); The Bolivian Case Against Chile At The Hague; Clear, Cogent Economic Arguments For Immigration; A Program To Say If I Am Working; Decent Cards For Ill People; New Photo; Luksic And Barrick Gold; President Bachelet's Speech; Baltimore Primer; libxml2 Parsing Stream; configure.ac Recipe For Library Path; The Davalos Affair For Idiots; Not The Onion: Google Fireside Chat w Kissinger; Bicycle Wheels, Inertia, and Energy; Another Tax Fraud; Google's Borg; A Verion That Redirects To Local HTTP Server; Spanish Accents For Idiots; Aluminium Cans; Advice on Spray Painting; Female View of Online Chat From a Male; UX Reading List; S4 Subgroups - Geometric Interpretation; Fucking Email; The SQM Affair For Idiots; Using Kolmogorov Complexity

© 2006-2015 Andrew Cooke (site) / post authors (content).

Auto-layout of Graph Components

From: "andrew cooke" <andrew@...>

Date: Thu, 19 Mar 2009 09:43:18 -0400 (CLT)

One of the projects I work on (at my paid job, ISTI) is a simple GUI
front-end to software that manages data for seismic detectors.  I don't
understand the underlying system completely, but it's component-based,
with many different processes, each configured separately, communicating
in real time via shared buffers.  Each installation is different, and some
rather complex, so can be a bit of a nightmare to configure, or to
understand an existing system.

Hence a GUI front end, although there are obvious limitations on what is
possible when you are layering on top of a system like that, especially
when the top layer must be as tolerant as possible to different deployment
scenarios.

Anyway, I wrote the code a while back (which is itself based on an earlier
system) and one thing we tried to add was a graphical display, showing the
interconnected processes and buffers.  The main problem (after inferring
what the connections are, which means reading each process's configuration
file) is providing a clear, flexible layout.

Originally I hoped to use a "springs" layout engine, which simulates the
physics of connecting the nodes with springs - if you're interested in
this kind of problem you've probably seen libraries like this.  However, I
couldn't find a good implementation for Python and was worried that
implementing my own would be too expensive.

So I went with a simpler option, which was to constrain the geometry to
two concentric circles, with the buffers on the inner circle and the
processes outside.  The exact ordering was calculated using simulated
annealing.  This seemed to produce reasonable results for my test system
(with a handful of buffers and maybe 10 or so processes), but I was unsure
how it would scale (I guessed at how various things would vary with graph
size and made the layout engine auto-adapt the parameters, but didn't have
another system to test it on).

Anyway, yesterday we finally used it on a larger client system.  The
result is here - http://www.acooke.org/ewfe-graph.png - and I am really
pleased.  Sure, there are more beautiful programs in the world, but for
the tradeoffs made I think this is a great result.  It should be a huge
help to the end user (clicking on the different components lets you edit
their configurations, stop/start them. etc etc).

Andrew

Comment on this post