Upcoming Conferences

I suppose everyone else’s mind is on the Desktop Summit in Berlin next week, but I’d like to take a moment to tout three conferences in the Netherlands later this year:

EuroBSDCon on .. well, everything BSD-ish, october 6th-9th 2011. There’s a fantastic line-up of speakers, including PC-BSD’s Kris Moore. That looks like the only desktop talk there, but the rest is equally nifty (not just because I like ZFS, SSH, SPARC and Dru).

NLUUG Fall Conference on IPv6 (and all the rest), october 20th 2011. The Call for Abstracts is open until August 1st, so not much time to drop a note (100 words is enough) to the programme committee. NetworkManager in transition would be a nifty topic, IMO.

PostgreSQL Conference Europe, october 18th-21st 2011. The Call for Papers is open until august 21st. All things Postgressy — the last talk I saw about the 9.1 release was amazing in terms of features.

Upgraded to KDE 4.7

Some people may find it odd that I don’t track KDE releases very closely — at least, not on my Linux machines, which includes my laptop. There things tend to be "whatever DVD is on the top of the pile gets installed" and updates happen only rarely. Quite different from my OpenIndiana or FreeBSD boxes, which track KDE closely.

Anyway, I saw so much buzz and enthusiasm for KDE 4.7.0 that I wanted to update my desktop machine at home. It was running Kubuntu 10.04 LTS (with whatever KDE came with that, probably KDE 4.4). That meant a three-step upgrade path: 10.04 to 10.10 (I used these instructions on techie-buzz), 10.10 to 11.04 (repeat the upgrade-to-newer-release steps) and 11.04 to 11.04 + KDE 4.7.0 (the install instructions are clear and point elsewhere to add the KDE backports repository — some of the screenshots don’t match what I saw, but it’s well done).

I hit one snag as the upgrade to KDE 4.7.0 (the last step) stopped counting progress at 66% and just sat there for an hour or more. I dented that and was quickly referred to the Kubuntu developers channel. That sorted me out quickly — I killed some processes and finished the upgrade from a text console. Big thanks to the Kubuntu folks who helped out.

Something else caught me during this upgrade — somehow, I must have moved the Plasma cashew at some point, because in 11.04 it was labeled "Desktop". Sure, PEBKAC, but it left me confused. Unlock widgets, drag it back into the corner and it turns back into my familiar quarter-circle. I gather it’s got to do with what activity I’m in — but I don’t think I’ve ever seen any of the activity-related stuff before. Thanks to RRix and Aaron for setting me straight there.

I have not tried some of the new stuff (e.g. the newest KDE-PIM applications including KMail2), but I’ve also not noticed some of the things people have been complaining about like over-enthusiastic indexing or Akonadi.

One of the neatest things I’ve seen so far — maybe this has been in KDE for years already, but it’s new to me — is that I started Akregator, by accident. Then I closed the main window. Akregator then goes to the system tray (er .. system notifications area? the thing, anyway). In doing so, it tells you where it’s going. Well I think that’s a great idea, but it even took a screenshot and drew a little arrow at the place where it would be, so I knew exactly where to look!

The meaning of oracles

A few weeks ago, Paul Adams (one of the folks whose innuendo I shall miss most in two weeks time) wrote about his newest oracle, which calculated something based on SVN logs. this Oracle of Ervin expresses a notion of connectedness in a group of developers working on shared resources.
That Oracle (for once in my blogging, not that database company) is related to Erdös numbers, and to Hirsch indexes) reminds me of some work I once did on software quality where we defined an “eyeball number” which was the number of distinct developers who worked on a given file. By fiddling around with the eyeball number modified by other factors we hoped to get some interesting indicator of software quality.
Indicator is the operative word here.
I think I can sum up (ha!) Paul’s Oracle of ERVIN as follows: given a set of developers D0…Dn and a set of shared resources (e.g. Files) create a graph with nodes D0…Dn and arcs (Di,Dj) if both Di and Dj have modified a resource R in the time period under consideration. If the resulting graph is connected, carry on. Otherwise, bail out with “OMG this community is not connected but rather like grains of loose sand!” Or perhaps redefine the set of developers to make the community connected.
Now we have a connected graph define Dij as the hop count from node Di to Dj (clearly Dii=0, Dij=1 iff an arc exists ie. They both modified the same software artifact). Finally define the connectedness Ci of developer Di as the average of Dij for all j.
(Drat WordPress and its lack of LaTeX support, btw)
After all that we have an indicator of .. something. If someone has a Ci close to 1 then that person has worked on a resource R that nearly every other person Dj has worked on (R may vary with Dj).
There is an obvious way to game this system which is called CHANGELOG. Of course everyone maintains that so in theory all developers work on that and so Dij=1 for everyone. Let’s ignore that resource then – there are plenty of heuristic ways to tighten up the set of resources R so we get something more meaningful.
Ah, but what does it mean?
Or, what does it mean?
I think where Paul went off the rails is only in calling Ci a measure of collaboration and using it to identify core contributors. Well, it might indicate (point at) some people as core contributors, but interpretation and further study – further data – is needed. So giving this indicator the right name is of some importance.
Aside #1: if I am a terrible coder and keep committing atrocities in the codebase and all other contributors fix up my abominations, then I might end up with a Ci (i=adridg) of 1. But then I would be the core of the problem, not the solution. Interpretation is needed – you may have to squint.
Aside #2: at work I was dealing with quality indicators (waiting times for patients and throughput for various conditions) and ran into similar problems as this indicator. What it’s called matters. How it is presented matters. Formulating the definitions in a way that is both understandable and valid is tricky. Get any of them wrong and you end up with plenty more of long discussions and reiterated definitional phases.
So where is all this headed? Certainly it illustrates that single-metric definitions rarely yield unambiguous results for concepts as ambiguous as “collaboration” or “core contributor”. This touches on the ALERT project (mentioned on the Dot and by Stuart). The system being designed there is about “stuff that’s happening that is inteesting for me”, collected, filtered and presented automatically. There is no single metric to do that – rather, clustering and heuristic approaches are needed. As the project goes on, there will be half-baked illustrations (mixed metaphor: should be scribbles) of what it finds. What I take away from Paul’s indicator is that presentation and interpretation are going to be very important. Also that critiquing an indicator is an art in itself.
So there you have it: tl;dr (length metric=N, formulas count=4, boringosity=17.6) and it means marketing metrics matters.


It’s the wettest July in ages. You might think that that is good weather for hacking, but no. I did discover that my raincoat is less waterproof than it ought to be. That shorted out my n900 in my pocket. It gives the kind of bing-bing sound of a low battery, then some high-pitched beeps and switches off. After shaking the water out and leaving it to dry overnight, things are fine again. Good engineering! On the other hand, if the phone had perished, I would have been looking hard at the N9.

My GPS logger, allegedly waterproof and floatable, also got waterlogged and did not fare nearly so well. I think the case developed a tiny crack when the kids dropped it and enough rain fell on it to flood it. It no longer charges.

Without my logger – I bought it some years ago after Robert Scott’s talk on Open Street Map in Glasgow, Curly-Wurlies were involved, but I never got around to actually contributing to OSM, which already has good material on Nijmegen – I am now looking for something on my phone to do the same. Marble? I see it updating regularly, but I find I haven’t used it for much, ever. Any other tips for a track-logging, export to useful formats (KML or UMEA sentences), doesn’t-eat-batteries GPS app for the n900? Comments welcome.