spec: generic sync plugin for Songbird

eric — Tue, 16 Dec 2008 12:01:38 -0800

I was going to whip up a python script to sync music to my mass-storage phone, but since I am using Songbird on all my platforms, the little extra effort to make a Songbird sync plugin will pay off big for me, and also be useful to lots of others.

the spec

Works with: USB mass storage devices
Options:

select connected device (persist selection?)
select disk usage setting (min free space or total usage?)
select playlists (these are songbird playlists, and may be ie mp3 blogs or rss feeds)

Behavior on sync:

remove oldest items
add newest items (so that disk usage is balanced among playlists or just so that newest items are available?)
optional renaming to maintain original playlist order (ie sequence-based naming)

Drupal as Open Architecture

eric — Fri, 21 Nov 2008 00:21:16 -0800

Wish I had seen this in August after OSCON, but it really strikes a chord. I’ve been a Drupal dev for a long time, and have recently been focusing on the newer “agile frameworks” in Python and Ruby, and I’ve found the same shortcoming: there is no component architecture, at least not on the level of Drupal with its myriad callback hooks and “monkey patching” facilities. I’ve been ruminating on the idea of following the Drupal architecture to build a similar framework on top of WSGI.

Personal Document Management

eric — Tue, 07 Oct 2008 16:42:38 -0700

I hate the boxes of paper records I have to lug around.

Some of the types of documents in my life:

Records of:
- Financial transactions
- Taxes
- Contracts
- Business cards
- Academic certificates
Papers I’ve written
- Math
- Creative writing

My goal is to put all my documents (paper and digital) into a single cross-referenced document management system with flexible metadata. Eric Blue recommends SCAN. From what I see, it looks simple and highly useful! I may start using this system and then convert to something else (probably a custom system based on RDF). I just purchased a nice scanner, so I’m going to implement this right away!

This fits into a larger goal of creating a unified model of all the entities I interact with, across all media.

Paper → Image → PDF → SCAN metadata store

Panels for Django

root — Mon, 06 Oct 2008 11:41:56 -0700

I ♥ Panels (it does the simple layout on this blog, but it’s capable of much more advanced usage).

Pro-tip: jEdit on network drive

eric — Sun, 05 Oct 2008 20:24:25 -0700

Most school networks provide users a personal network folder mounted as a Windows network drive and accessible from any campus workstation. This is primarily meant as a document folder, but executable programs can be stored here too. I have several useful programs in my network folder, but the most useful by far is jEdit. The same copy runs on both Windows and Mac workstations, with the same plugins and configuration options.

To use jEdit in a network environment, just make sure that your jEdit user settings directory is stored on in your network folder by launching jEdit with

“jedit.jar -settings=P:/ath/to/your/folder/.jedit”

via an application shortcut in windows, or a shell script on Mac/Linux (jEdit is an executable jar). Enjoy!

Can Paper Think?

eric — Sun, 05 Oct 2008 13:59:45 -0700

An empty husk of a posting.

Portable Document Repository

eric — Sat, 04 Oct 2008 17:53:12 -0700

Microcontent can be easily transferred between infosystems. Simpler data formats are simply more portable.

By organizing your information as microcontent, you can easily implement various distributed workflows, including

local checkout of individual items
consolidation (aggregation)

As the device market gets more complicated, .NET and Java propose to achieve portability through homogeneity, but the browser remains the single (somewhat) universally available client platform. The key difference is that the web grew around portable data formats, not portable code.

Serving web content from flat files (RDF, Git, Textile, XHTML)

root — Sun, 27 Jul 2008 15:19:31 -0700

At the OSCON Django meetup last Tuesday I asked some vim aficionados how they managed to keep their .vimrcs synchronized between different hosts. I myself prefer to use a network-aware editor like jEdit and KDE’s kate to avoid platform quirks.

Summer

root — Sat, 24 May 2008 14:25:57 -0700

I won’t be taking any other math classes this Summer (except 2 credit independent study), and the work I’ll be doing is bound to be highly personal. We’re talking, tricked out home site and portfolio, doing work with friends such as the relaunch of of Marjorie Bevis’ Marbled Fabrics, and perhaps the genesis of some sort of local peer-commerce/underground economy social networking site, which has been in conceptual stages among my friends.

Nokia 770 Hackathon Notes

eric — Tue, 08 Apr 2008 23:48:42 -0700

Poky linux 3.1.

supports 770 with image
doesn’t come with wifi driver, power mgmt

Wireless

Chipset is cx3110 with bitbake recipe in poky. How to build this in an image?

power-management

Intro to Sage

eric — Tue, 29 Jan 2008 16:53:02 -0800

Useful Links

Sage is…

A general purpose symbolic computer algebra system (CAS) like Mathematica, Maple, Magma, etc.
Designed to be accessible and useful right away for people with some math background.
Accessed through your browser.
Powerful, as we shall see…

Why Sage? We have Mathematica…

Cost.

Homepage Dreams

eric — Fri, 18 Jan 2008 21:38:20 -0800

I would like to get my homepage in shape (easier than myself). I saw Magnus' homepage and was inspired. Magnus is the author of the Epilicious extension for Gnome's Epiphany web browser. I found his site while trying to file a bug report for same. He is interested in some of the same things as I am, but his site is well-organized, friendly to navigate, and full of content.

Getting my hands dirty with MTH 421 ODEs

eric — Wed, 16 Jan 2008 22:28:54 -0800

The author of my ODE text V.I. Arnold giving the modern (last 50 years) abstract mathematics curriculum a sound flogging. Quite entertaining IMO.

PSU BS Mathematics Planner

eric — Fri, 21 Sep 2007 14:15:32 -0700

BS Math requirements
Unfilled:

Mth 256 or Mth 421: Differential Equations
Mth 311, 312: Advanced Calculus
Mth 344: Group Theory

PSU BS Requirements:

2 terms Foreign language
Upper-division cluster (12 credits)
Senior capstone (6 credits)

Enroll in honors program?

Useful Drupal Links

root — Thu, 09 Aug 2007 12:37:27 -0700

API Documentation for Drupal core
Contrib module project pages. Issue tracking, CVS browser, releases, documentation.
Drupal Lists
#drupal-support on freenode

read more

Back in Portland...

eric — Sun, 29 Jul 2007 18:34:31 -0700

... for the third time this week, a record.

I'm staying the night at the Washington Park Inn, an affordable option downtown since the NW Intl Hostel is full up. Hope to sleep long and sweet tonight. View of downtown, bridges, construction:

Dinner care of Fred Meyer's deli, leftovers in the mini-fridge.

My things to do list is as follows:

Get cash (onpoint) since I left my debit card at Heather's.

read more

My Friends

eric — Tue, 24 Jul 2007 16:02:28 -0700

http://akuatuta.freeservers.com/

plant and animal sightings (and lichens)

eric — Sun, 08 Jul 2007 20:49:13 -0700

Me and Heather are going to make a website! We take lots of pictures of native plants, animals, lichens etc, and this will be a database of amateur sightings. Of course anybody can contribute their own sightings, and we will have a rating system so really neat pictures etc can float up.

Todo:
- temp domain (can't login to dyndns.org?)

collect:
- coordinates (or address)
- Photo
- species tags (free at first?)
maps

The Continuing Quest for Freedom from Telco Tirany

root — Mon, 11 Jun 2007 22:46:53 -0700

Rant

Why is Skype evil?

They choose to create their own proprietary network rather than interoperating with SIP, for the sole purpose of building a monopoly. Sure, it makes good business sense for them, since they are doubtless far more profitable than any public SIP service trying to compete in the same space. Can we blame them for wanting to make some dinero? No, I guess not. Will we fight them for control of the network? Duh of course!

Anyway, I've been using Skype for awhile since certain people I talk to also use it (there's the lock-in bit). Gizmo was pretty good, but not good enough (connection under bad conditions on public wifi etc was better under skype). Skype has its own cross-platform SIP client (using Trolltech's excellent dual-license QT library of course), which is free as in beer, but not Free Software. Anyway big woop. It also doesn't do video.

FF_>> 6 months, and now the market is starting to shift around a bit. Wengo, a France-based SIP provider, has produced a very interesting SIP client:

Actually cross-platform (again via QT), unlike Skype which has a different and buggy version on each of Win, Lin and Mac.
Open source, and using open components (big woop), unlike Gizmo or Skype
Full-featured chat with all the major nets (MSN, AIM, Gtalk, IRC.....)
Video! Cross-platform video, fi-na-lly! Hallelujah!
Polished so it glistens. It's odd actually, the company clearly has enormously skilled and motivated engineers, but very poor marketing. They must have some other income source, perhaps in partnerships with Telcos.

The latest Wengophone release (2.1) claims to allow connections to other SIP providers. This is important because Wengo's service:

is in French / France
doesn't include important features like a US call-in number

So anyway I'm thinking that Sipphone's service might be the perfect match for Wengo's client. Testing follows, this article to document results.

Wikipedia does spoken articles

root — Mon, 11 Jun 2007 13:04:14 -0700

http://en.wikipedia.org/wiki/Category:Spoken_articles

I'm listening to the Lego article, it's a good format to listen to while doing something else, not too distracting but you pick up interesting snippets here and there.

Perfect number finder in python

root — Sun, 10 Jun 2007 02:00:23 -0700

In the interest of greater openness (sharing my inner life with the world and such), here is a bit of python I just wrote to find perfect numbers. After a few minutes of optimization, it is now quite fast and no longer brings OSX to its knees with memory-hungryness:

from math import *
def is_perfect(a):
	sum = 1 
	for i in xrange(2, floor(sqrt(a))):
		if a%i == 0:
			sum = sum + i + a/i
	if sqrt(a)%1 == 0: sum += sqrt(a)
	return sum == a

def find_perfect(limit):
	results = []
	for i in xrange(1, limit):
		j=2**i*(2**(i+1)-1)
		if is_perfect(j):
			results.append(j)
read more

Uke stuff

eric — Tue, 08 May 2007 20:10:54 -0700

I bought a ukulele a few months ago, the $20 China special at one of the 3 string shops in downtown Corvallis. I don't play any songs all the way through yet, but this guy's rendition of the (NES, Level 1-1) Mario Bros. theme on the uke should hold you over:

I find this ukulele chordfinder very useful. Also surf around their site, if you can figure out the wacky navigation. It's a media playground!
My favorite ukulele tablature site.
Article on relative tuning method

Summer of Code Proposal

eric — Sun, 25 Mar 2007 14:54:57 -0700

Motivation

In building a content-oriented website, people need a way to specify
structure (how the pages and content items of the site inter-relate)
and provide navigation based on the structure.

Most existing tools for site-structuring and navigation in Drupal are problematic for two main reasons:

HW #5: Spherical Coordinates, Duex

eric — Sun, 18 Feb 2007 22:31:23 -0800

This work is borrowed gratefully from Flanders 4.1.

Position in is given in terms of spherical parameters as:

with basis . Applying the exterior derivative operator gives:

&+ (r\cos{\phi}\cos{\theta}, r\cos{\phi}\sin{\theta}, -r\sin{\phi})d\phi \\
&+ (-r\sin{\phi}\sin{\theta}, r\sin{\phi}\cos{\theta}, 0)d\theta \\
= &dr\hat{r} + rd\phi\hat{\phi} + rd\theta\hat{\theta} \\
\end{align*}" />

with

\hat{\phi} &= (\cos{\phi}\cos{\theta}, \cos{\phi}\sin{\theta}, -\sin{\phi}) \\
\hat{\theta} &= (-\sin{\phi}\sin{\theta}, \sin{\phi}\cos{\theta}, 0) \\
\end{align*}" />

Therefore, (answer part (a))

&+ (\cos{\phi}\cos{\theta}, \cos{\phi}\sin{\theta}, -\sin{\phi})d\phi \\
&+ (-\sin{\phi}\sin{\theta}, \sin{\phi}\cos{\theta}, 0)d\theta \\
= &\hat{\phi}d\phi + \hat{\theta}d\theta \\
d\hat{\phi} = &(0,0,0)dr \\
&+ (-\sin{\phi}\cos{\theta}, -\sin{\phi}\sin{\theta}, -\cos{\phi})d\phi \\
&+ (-\cos{\phi}\sin{\theta}, \cos{\phi}\cos{\theta}, 0)d\theta \\
d\hat{\theta} = &(0,0,0)dr \\
&+ (-\cos{\phi}\sin{\theta}, \cos{\phi}\cos{\theta}, 0)d\phi \\
&+ (-\sin{\phi}\cos{\theta}, -\sin{\phi}\sin{\theta}, 0)d\theta \\
\end{align*}" />

HW #3

eric — Tue, 13 Feb 2007 15:35:31 -0800

Hodge Dual in Minkowski Space

Minkowski 4-space has orthonormal, oriented basis with volume element (choice of orientation) and inner product defined by

g(dx,dx)&=1 \\
g(dy,dy)&=1 \\
g(dz,dz)&=1 \\
g(dt,dt)&=-1 \\
g(d\alpha_i,d\alpha_{j\ne i})&=0 \\
\end{align*}" />

Determine the Hodge dual operator * on all forms by computing its action on basis forms at each rank.
In general, the dual can be computed as (Equation 20, http://oregonstate.edu/~drayt/Courses/MTH434/2007/dual.pdf):

where is the volume element.
In particular:

\ast 1=\omega
\end{align*}" />

\ast dx &=dy \wedge dz \wedge dt \\
\ast dy &=(-dx \wedge dz \wedge dt) \\
\ast dz &=dx \wedge dy \wedge dt \\
\ast dt &=(-1)(-dx \wedge dy \wedge dz) \\
\end{align*}" />

\ast dx\wedge dy &=dz \wedge dt) \\
\ast dx\wedge dz &=(-dy \wedge dt) \\
\ast dx\wedge dt &=(-1)(-dy \wedge dz) \\
\ast dy\wedge dz &=dx \wedge dt) \\
\ast dy\wedge dt &=(-1)(-dx \wedge dz) \\
\ast dz\wedge dt &=(-1)(dx \wedge dy) \\
\end{align*}" />

\ast dx \wedge dy \wedge dz &=dt \\
\ast dx \wedge dy \wedge dt &=(-1)(-dt) \\
\ast dx \wedge dz \wedge dt &=(-1)dt \\
\ast dy \wedge dz \wedge dt &=(-1)(-dt) \\
\end{align*}" />

\ast \omega = -1
\end{align*}" />

How does your answer change if the opposite orientation is chosen, namely ?
The sign of each dual would change, due to the additional odd number (3) of transpositions to the volume element. The sign of the number of transpositions required to transform one volume element into another is an invariant (independent of a particular permutation).

Spherical Coordinates

Spherical coords in with \theta}dr\wedge d\theta \wedge d\phi $" />
1. Calculate the action of * on the basis elements of each rank.
2. Compute the dot- and cross-products of 2 arbitrary "vector fields" (1-forms) using the expressions:
  
  \alpha\cdot\beta&=\ast(\alpha\wedge\ast\beta) \\
  \alpha\times\beta&=\ast(\alpha\wedge\beta) \\
  \end{align*}" />

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