Tuesday, December 23, 2008

Scala

Andrew has been pretty enthusiastic about Scala, which he is using for his new factor graph inference library, FACTORIE. I've been reading the new Programming in Scala to learn more. I've not written any Scala code yet, except for a "Hello world" to test the Eclipse plugin. I like the improved conciseness compared with Java, the functional programming facilities, the more uniform object system, the more consistent data structures, the pattern matching facilities. I'm still unsure about the syntax, which feels a bit too clever at times, and skeptical about the use of type-erasure semantics for generics, which has many pitfalls in my experience with teaching and using Java. However, the Scala designers seem to be well aware of the problems with (at least Java's version of) type erasure and are exploring ways of addressing them.

The future is a shoe being thrown at a human face - forever! — Crooked Timber

The future is a shoe being thrown at a human face - forever! — Crooked Timber: [...]Which brings me to the actual topic of the post; a link to a post on my other blog where, in comments, we have been working out job-related mortality rates for a variety of professions.

[...Units: deaths/year-on-the-job...]

President, USA - 2283
Pope – 2126
Hezbollah, active member – 1000-2000
Prime Minister, UK - 937
Monarch, England/UK – 912
Monarch, France – 890
Soldier, Iraqi Army – 800
Soldier, US Army (while in Iraq, March 2003-March 2006) – 392
Fisherman, Pacific Northwest crab fishing – c400
Timber-cutter – 117
Fisherman, overall – 85
Soldier, US Army – c80
(Via Matt Yglesias.)

What about backcountry skiers?

Sunday, December 21, 2008

Eastern Sierra from afar

I flew yesterday over the Eastern Sierra just North of Mono Lake on my way to Philadelphia for Christmas. I looked hungrily at the snowy terrain down there, which I want to visit before this season is over.


Sunday, December 7, 2008

Police launch appeal after grim series of avalanche fatalities

Police launch appeal after grim series of avalanche fatalities: The man, a Nicois, was part of a group of three boarders who crossed under netting at the top of the pistes to ski a ridge into a bowl. [...] was buried under 300cm of snow. [...] was not wearing an avalanche beacon. (Via PisteHors.com.)

The beacon would have likely been a sad redundancy in this case, just helping the rescuers to recover the body more easily. The odds of being dug alive from under three meters of avalanche debris are negligible.

Although the statistics are not fully in, it seems that a reduction in fatalities among practiced backcountry riders is being offset by an increase in reckless behavior by "side country" riders who get into uncontrolled terrain from ski lifts. Moving further into speculation, easier to use equipment and very aggressive publicity for off-piste riding in movies, internet videos, and magazines may also be factors.

Saturday, December 6, 2008

Let it snow

Ed Berry:
Models have now generally caught on to what some would describe as a large amplitude reverse/negative phase of the PNA teleconnection by week-2. I think it is probable this situation may persist the rest of this month per above. As discussed in past postings, particularly weeks 2-4 there should be episodes of significant precipitation along the USA west coast associated with “cold” digging troughs, leading to an active southwest flow storm track across the Plains. Weather ramifications, including high impact blizzard conditions and intense thundersnow in the cold sectors and severe local storms in the warm sectors of synoptic lows, should be understood.

Let’s Talk About Python 3.0

Let’s Talk About Python 3.0: Thoughtful essay by James Bennett in support of Python 3.0. Love the opening.

I agree that the opening is a great cautionary tale. However, the actual Python 3.0 content is even better, because it gives an interesting example of difficult software engineering tradeoffs being worked out through serious debate and attention to conceptual, craft, and social issues in programming. I especially like the discussion about Unicode, because I never understood why previous solutions allowed confusion between a string over a given alphabet and byte encodings of such strings. But then I remember that computer science faculty and students seem to have perversely conspired to make automata and formal languages seem totally irrelevant, so that the simple notion of an injective homomorphism from $\Sigma^*$ to $\Gamma^*$ is no longer obvious to all concerned. (Via Daring Fireball.)

Waiting for snow

High pressure still rules the Sierra, but a door may be cracking open:
LONG TERM /TUESDAY THROUGH FRIDAY/...
CONFIDENCE REMAINS HIGH THAT A RIDGE WILL REMAIN OVER THE WEST
TUESDAY AND WEDNESDAY. THIS WILL MAINTAIN STRONG NIGHTTIME
INVERSIONS WITH NEVADA VALLEY HIGHS NEAR NORMAL. HIGHS IN THE
SIERRA WILL BE 10 DEGREES ABOVE NORMAL.
FORECAST BECOMES LESS CERTAIN FRIDAY AND SATURDAY /DEC 13TH/ AS
MODELS DIVERGE AND ENSEMBLE SPREAD REMAINS HIGH ACROSS THE NORTHEAST
PACIFIC. THE RIDGE SHOULD RETROGRADE TO AT LEAST 140W ON
THURSDAY...WHICH TURNS THE FLOW ALOFT TO THE NORTH OR NORTHWEST.
THIS WILL OPEN THE REGION TO A COLD FLOW...WITH AIR DROPPING SOUTH
OUT OF NORTHERN CANADA OR THE GULF OF ALASKA.
THE GFS IS FARTHER WEST WITH THE RETROGRESSION OF THE RIDGE TO ABOUT
150W...WHILE THE ECMWF IS NEAR 140W. THE GFS SOLUTION WOULD FAVOR A
SIGNIFICANT INCREASE IN WINDS FRIDAY NIGHT INTO SATURDAY ALONG WITH
A HIGHER POTENTIAL FOR ACCUMULATING SNOW AS THE STORM TRACK IS FROM
THE GULF OF ALASKA. THE ECMWF WOULD BE COLDER THEN THE GFS...DRIER
WITH ITS STORM TRACK REMAINING OVER LAND BUT WOULD STILL PRODUCE
SNOW SHOWERS AT MOST LOCATIONS.

Reading...

Sea of Poppies, thanks to Chris Lydon's interview of Amitav Ghosh.

Tuesday, December 2, 2008

Truthy math

Slightly evil question: is TeX truthiness for math? It's so beautifully typeset, it feels so true.