Property Allocation

So, the rigors of four independent people sharing one refrigerator and kitchen have finally caught up with this house. All de facto boundaries of personal "spaces" within our fridge have disappeared in the previous weeks. Finding my cream pushed behind someone's leftovers and spilled has empowered me to speak out.

I'm working on a solution for this and the other common spaces problem. People have laid claims to their storage areas, some of which are unreasonable. People leave dishes in the sink, also unreasonable. Messes get ignored and grow as a result, unreasonable.

What have the readers of this blog implemented when sharing living spaces with people you weren't sleeping with? Any pitfalls? How did you keep dishes out of the sink?

Oh, and the first person to cite Garret Hardin's specious "Tragedy of the Commons" gets a cock punching. We're not talking about sterilizing human beings to keep the Earth from being overpopulated. We're not even talking about consuming commonly held goods. I'm just designing a workable attitude toward property rights with respect to space and time to avoid inefficiency and to prevent people from resenting and hating the others. Perhaps it's a little late, but it's a good experiment.

Golub and Van Loan wear the clock so you can know the time

Just thought I'd share the magic.

U = 
[
0.3594  -0.5577  0.5229  -0.4077  0.3128  0.1494 ;
0.4158  -0.4082  0.0545  0.4089  -0.5689  -0.4082 ;
0.4449  -0.1494  -0.4741  0.4072  0.2794  0.5577 ;
0.4449  0.1494  -0.4729  -0.4093  0.2786  -0.5577 ;
0.4158  0.4083  0.0558  -0.4076  -0.5697  0.4082 ;
0.3594  0.5577  0.5216  0.4088  0.3135  -0.1494 ;
];

B = 
[
-30.5509  -0.0006  -0.0000  -0.0000  -0.0000  0.0000 ;
-0.0000  -7.4641  0.0001  -0.0000  -0.0000  0.0000 ;
-0.0000  -0.0000  1.7912  0.0035  -0.0000  0.0000 ;
0.0000  -0.0000  0.0000  1.0000  0.0008  0.0000 ;
-0.0000  0.0000  0.0000  -0.0000  0.6579  0.0000 ;
-0.0000  0.0000  0.0000  -0.0000  0.0000  -0.5359 ;
];

V' = 
[
-0.3594  -0.4158  -0.4449  -0.4449  -0.4158  -0.3594 ;
0.5577  0.4082  0.1494  -0.1494  -0.4083  -0.5577 ;
0.5234  0.0540  -0.4746  -0.4724  0.0563  0.5211 ;
-0.4072  0.4092  0.4065  -0.4100  -0.4073  0.4093 ;
0.3126  -0.5687  0.2796  0.2784  -0.5699  0.3137 ;
-0.1494  0.4082  -0.5577  0.5577  -0.4082  0.1494 ;
];


U B V' = 
[
7.0000  6.0000  5.0000  4.0000  3.0000  2.0000 ;
6.0000  7.0000  6.0000  5.0000  4.0000  3.0000 ;
5.0000  6.0000  7.0000  6.0000  5.0000  4.0000 ;
4.0000  5.0000  6.0000  7.0000  6.0000  5.0000 ;
3.0000  4.0000  5.0000  6.0000  7.0000  6.0000 ;
2.0000  3.0000  4.0000  5.0000  6.0000  7.0000 ;
];
U and V' are unitary.

Working on making SVD converge as fast as possible and to minimize storage requirements. Right now, it holds a whole copy of the tridiagonal matrix B. Storing a lot of elements known to be zero is a bit wasteful, if you believe that information theory voodoo.

Yes, I realize the output B is not *quite* diagonal, but that's with four iterations of the diagonalization process (two Givens rotations per row) and no explicit zeroing of elements.

Problems to solve:
* minimize storage requirements for B.
* figure out whether it is possible to store U and V in factored Householder forms and accumulate the Givens rotations some other way (as opposed to forming U and V explicitly then rotating them to diagonalize as I do now).
* complex Householder reflections

Singular Venereal Disease

Implemented singular value decomposition in a sense. It's not integrated into VSIPL but rather written as a VSIPL application. That'll change in the next few days.

As the reference implementation of VSIPL lacks this functionality, I'm told I can submit mine to VSIPL forum for distribution perhaps. That'd be a feather in my cap.

My HPEC presentation is taking shape. I have to cover a slide a minute as it is. Probably should condense it.

Emma's here. No more time for interwebs!

Weather Models

Frequently, news articles covering global warming cite weather models that predict the Earth's climate will warm in the coming decades. The articles never mention whether said models have accurately predicted past meteorological trends given historical data. Sometimes articles explicitly claim the models have not. In all cases, the expectation for a model to explain the past is categorically ignored.

I'd like to propose what appears to be an equally valid weather model:


printf("Earth's climate will be hotter 100 years from now.\n");


This clearly achieves the modern standard of rigor for getting the model published. It was cheap to develop, and as a bonus, it accurately confirms what we already know about the future of our planet!

Surely you don't disagree with overwhelming popular opinion on the subject...

DC Exploration

On Thursday, I attempted to visit the Whitehouse to conduct a self-guided tour. On the Metro, I began to sweat profusely and feel light-headed. By the time I approached McPhereson Square, bloodflow to my brain apparently decreased so much that my vision became impaired. I willed myself to remain upright, and when the doors opened I walked forward and groped around for a railing on the platform. I was completely blind by then. Bad news. I'm okay now though.

I need to transmit my medical care facility doctor's note to the person who arranged my tour so they don't think I'm a slacker who failed to show up because I don't value free things.

--

My parents and sister arrived later that evening. We ate Chinese down the street and planned our weekend. I had to work Friday, so they visited Smithsonian museums of their choice. We went to eat at Nathans in Georgetown again which ruled. Saturday, my dad and I drove out to Dulles to see the Steven Udvar-Hazy Center. This is perhaps the greatest single aviation exhibit I've ever seen, and I will gladly take any readers who visit and be just as thrilled to go a second time.

I have photos, but they require post-processing and downsampling. I'll try to get them up soon. I'm creating a flickr account. A separate post will chronicle what was seen with perhaps a way to prevent the strong-willed reader from avoiding spoilers.

Saturday night we ate at The Front Page in Ballston then drove down to the Iwo Jima Memorial after supper. This proved a wise choice as it was low key, parking was free, and the view was splendid. The Netherlands presented the US with a carillon tower in 1960 as a way of demonstrating gratitude for liberating them from the Nazis during 1944-45. A player comes Saturdays from 6pm-8pm and plays. With the gates unlocked, my sister ran up the stairs to obtain a 100ft higher view of Arlington National Cemetery, the Potomac, and the Mall across the river. Next week, I plan to drag Emma along closer to 6pm such that there is more light and take photographs.

Sunday, we returned to the National Gallery and I saw the only Da Vinci work in the United States: Ginevra de Benci. It is painted on both faces of a wooden panel and is mounted in a free-standing exhibit so you can see the reverse as well as the obverse. Ginepro is apparently the Latin term for juniper tree and was used to symbolize chastity. Now we see it as a precursor to gin.

With that, they left Sunday afternoon to split the trip in half. We ate well, and everyone seemed to have a splendid time.

Hype v Economics

Scary

The element gallium is in very short supply and the world may well run out of it in just a few years. Indium is threatened too, says Armin Reller, a materials chemist at Germany’s University of Augsburg. He estimates that our planet’s stock of indium will last no more than another decade.

Not so scary [ArsTechnica]

One of the arguments trotted out in most posts focuses on the fact that the price of Indium has risen from around $95 in 2002 to over $1000 in 2006. What these posts fail to point out is that it was around $180 in 2000, so $95 appears to have been carefully chosen as a starting point. The end point is pretty suspicious as well, given that Indium's price was around $665 in May. Meanwhile, everyone fails to point out that the price of Gallium has remained flat in recent years.

To understand why the supply side has not increased production substantially with this increase in price, you have to look at how Indium is produced. Indium is extracted from raw materials mainly as a by-product of Zinc production. Because the price of Zinc has not increased recently, and may decrease in the near future, producers have little incentive to increase output.

Let's try to keep our heads, Internet.

July 4th Celebrations

Part 1 of my July 4th plans included grilling. The day was sunny, clear, and cool. My roommate Carter and I proceeded to skewer a number of chunks of beef and chicken. We included slices of onion, peppers, and zucchini. With kabobs constructed, I attempted to get a fire roaring on our kettle grill. Rather than rest the fuel on a grate above air vents at the lowest point and rely on convection to produce a flow of oxygen, our grill is simply a large pan. Given the dimensions of the fire I attempted, the result was an anemic heat that demanded approximately 45-60 minutes to grill each kabob.

The result may have been worth it. Each cut was tender and juicy. All those involved concluded the grilling was a success.



Still, air holes will be nice.

--

I spent the rest of the day at home. Some of that time was spent coding. When it was time for fireworks, I remained indoors due to rain.

I spent Saturday indoors as well, though I went out for a midafternoon pedal down the bike paths of Arlington. A rather interesting rail follows I66 all the way to the Key bridge from George Mason Dr (my stoop, practically). Atlanta is missing out.

July 4

[from Declaration of Independence]


We, therefore, the Representatives of the united States of America, in General Congress, Assembled, appealing to the Supreme Judge of the world for the rectitude of our intentions, do, in the Name, and by Authority of the good People of these Colonies, solemnly publish and declare, That these United Colonies are, and of Right ought to be Free and Independent States; that they are Absolved from all Allegiance to the British Crown, and that all political connection between them and the State of Great Britain, is and ought to be totally dissolved; and that as Free and Independent States, they have full Power to levy War, conclude Peace, contract Alliances, establish Commerce, and to do all other Acts and Things which Independent States may of right do. And for the support of this Declaration, with a firm reliance on the protection of divine Providence, we mutually pledge to each other our Lives, our Fortunes and our sacred Honor.




I shall observe this glorious occasion with kebobs and dry ice.