Tea Total

Moving

2005-11-15T20:41:00.000-08:00

I'm moving to a new bat place and new bat format: Numerical Notes. This move is spurred by a combination of technical and personal considerations. On the technical side: I mostly spend my evenings away from computer networks, which means that the times I'm most likely to take a break and blog are also the times that I'm least likely to have the connectivity to post anything. Also

Understanding and reviewing

2005-10-04T20:02:00.000-07:00

In How to Solve It, Polya lists four steps for mathematical problem-solving: understand the problem, devise a plan, carry out the plan, and then look back. It seems like I spend most of my time -- or at least most of my interesting time -- in the understand the problem or the look back phases. In some sense, I spend way more time in the phases of initial understanding and later

Another week in books

2005-10-03T15:13:00.000-07:00

Adventures of a Mathematician (S. Ulam) Did I finish this two weeks ago? In any case, it was interesting to read. In addition to the autobiographical and historical comments, Ulam says a great deal about mathematics and mathematical ways of thinking. Though he sometimes mentions specific technical areas, almost all of the book is accessible to a general audience.

Windows woes

2005-10-02T12:06:00.000-07:00

I wish I had a better idea how to effectively use a Windows box at a distance. Now that my old laptop is retired, I no longer have such easy access to a Windows machine. The department has a server that I can use with rdesktop, but it's of limited usefulness: I can't run MATLAB on it to compile my codes; I can't print from it; and for security reasons, I can't access it from the

Frequently searched questions

2005-09-28T18:44:00.000-07:00

The word you're thinking of is teetotal. It's an adjective that describes one who does not drink. It is a pun, since I prefer tea to alcohol (though I've decided a cup of cider from time to time is okay, too). There are two aspects of MATLAB EXternal interface (MEX) programming that cause most of your headaches. First: when you use the mex script, the compiler

Time out for reading

2005-09-19T10:36:00.000-07:00

Time out for reading There is a new Half Price books in Berkeley, along Shattuck Avenue a couple blocks west of campus. Curiously, they're in the same space as the dollar store where I got some pans and utensils just after I moved to Berkeley. As part of their opening celebration, they have an additional 20% off. So I wandered in, saw some familiar faces, and picked up a few

Multiples of q

2005-09-19T10:35:00.000-07:00

You probably learned this trick in grade school: to see whether a number is divisible by three, add all the digits and check if the sum is divisible by three. The same thing works for nine. Ever wonder why? Actually, three and nine are just special cases of something very general. What does it mean if q divides n evenly? It means that there is ultimately no remainder in the

Penguins

2005-09-16T11:15:00.000-07:00

A friend pointed out this, which I think is one of the most entertaining uses of GIF animation that I've seen in a long time.

A little long division

2005-09-12T09:54:00.000-07:00

Suppose p and q are relatively prime integers, and 0 < p < q. If q has any prime factors besides 2 and 5, then a decimal expansion of p/q will eventually start to repeat. How long will the repeating part be? Looking at the sequence of digits is actually a very difficult way to approach this problem. It's much simpler to look at the sequence of remainders. Remember how long division works.

Honest exercise

2005-09-06T17:01:00.000-07:00

Alas, we didn't get through all the Common Lisp exercises I'd planned for section today. This is too bad, because I would have liked to have people think about the last exercise: given a collection of (programmer program) pairs, how can you find the sets of programmers with structurally identical codes? It took me about five minutes to do this one (though this may be because I

Law and linear algebra

2005-09-05T11:34:00.000-07:00

The Economist has an article on using linear algebra network analysis tools to identify important legal cases. This is the same technology used by some search engines to find important web sites (hubs and authorities). I learned about this from a posted on NA digest. Currently drinking: Coffee

Cycling for digits

2005-09-05T10:49:00.000-07:00

There's a computer language called Nickle which grew out of something Keith Packard started working on two decades ago because he needed to do a little arbitrary-precision calculation. One of the entertaining features of the language, particularly if you're trying to teach people about compilers, is the treatment of rational numbers. Every rational number can be written as a

On the radio

2005-09-03T13:44:00.000-07:00

The AC voltage provided by the local power company is a bit over 60 Hz. Consequently, most of the clocks in the house (excepting the battery-powered ones) end up running fast. They all got reset to the correct time when daylight savings started; now they're about fifteen minutes out of sync. Consequently, my alarm goes off at 7:15, now, even though the clock thinks it's 7:30. I

Fall 05

2005-08-25T17:41:00.000-07:00

Classes start next week. How about that? A couple years ago, I was the TA for the local graduate parallel computing course. That was a lot of fun, though it was also a lot of work. Kathy Yelick has done a lot with performance tuning and language design for parallel machines; and I'm a numerical analyst who happens to know something about systems. So I think the folks taking the

Local names

2005-08-24T16:08:00.000-07:00

Modern programming languages support the notion of restricted lexical scope: the meaning assigned to a name can be made to hold only over restricted sections of the program text, allowing the programmer to re-use the same symbol to refer to different things depending on the context. It's hard to overstate how useful this is. It's so useful, in fact, that we fake it when we don't have

Essays interspersed

2005-08-23T09:21:00.000-07:00

Richard Gabriel, Paul Graham, and Peter Norvig all have sites of essays. Norvig has more technical stuff than Graham or Gabriel, but all three collections are worth browsing. I've already mentioned Graham's essays, but if you're unfamiliar with the other two: Norvig is Director of Search Quality at Google, but I know him better as the author of The AI Book (together with

Day in the life

2005-08-16T16:01:00.000-07:00

Get up. Coffee. Tease flatmate. Taylor's theorem, integration by parts, Cauchy-Schwartz. Rinse and repeat. Get error estimate. Check numerically whether estimate holds for simple test case. Discover algebra errors in the proof. Correct proof. Discover algebra errors in the test program. Correct test program. Discover errors in the compiler. Swear. Let out cat, who is

Starts with P

2005-08-14T13:59:00.000-07:00

Public transportation I visit Winnie in San Jose most Saturdays. The full trip proceeds in three legs: a BART ride to Fremont, a bus ride to a transfer station at the Great Mall transit center, and a light rail ride to a stop near Winnie's apartment. Depending on how long I spend waiting between each leg (and whether I meet Winnie at her apartment or at Great Mall), the trip

Messiness and computing

2005-08-12T12:25:00.001-07:00

Heidi recently wrote an entry in praise of messiness in science, which set me thinking about messiness in mathematics and in computing. While reading some of Dijkstra's old writings, I came across this tidbit, which seemed apropos: We should never forget that programmers live in a world of artifacts, a fact that distinguishes them from most other scientists. A programmer

Three books

2005-08-12T12:25:00.000-07:00

The Structure of Scientific Revolutions. Thomas Kuhn You've heard of this book, even if you don't think you have. Kuhn gave the modern meaning to the phrase paradigm shift. You may recall that I mentioned this book -- a month ago, perhaps? It took me a while to read it, just as it took me a while to read it the first time I was exposed to it some ten years ago. I tried

Backstroke of West

2005-08-11T13:46:00.000-07:00

There's an old story about the phrase the spirit is strong, but the flesh is weak being translated to Russian and back to English to yield the vodka is good, but the meat is rotten. I thought that was funny. I nearly hurt myself reading about this English-subtitled Chinese edition of Revenge of the Sith. Back to Sobolev estimates.

Little things

2005-08-09T15:15:00.000-07:00

I like pen and ink drawings, the kind in which every line is critical to the picture. I enjoy short poems, sonnets, and lyrics in which each sound and connotation is placed just so. I appreciate Strunk and White, Kernighan and Ritchie, and Rudin. I love ripe summer tomatoes with naught but a sprinkle of salt. Romantic landscape paintings, Wagner's Ring Cycle, Gibbon's history,

Search terms 2

2005-08-05T16:03:00.000-07:00

Searching for Lisp tokenizer or Lisp parser -- nearly useless. Searching for Lisp regular expression -- much more useful. Google -- priceless.

Macro expanding disclaimers

2005-08-05T15:14:00.000-07:00

From the CLiki Common Lisp resource site: Imagine a fearsomely comprehensive disclaimer of liability. Now fear, comprehensively.

Linear B

2005-08-03T17:50:00.000-07:00

I gave my advisor an early draft of my thesis early in May; he returned the marked up version to me a couple weeks ago. There was a section in my draft which I cut from previous documentation of one of my codes in which I described the mixed-language structure of the code as a combination of C++, Fortran, Lua, MATLAB, and Minoan linear B script. I forgot to cut the last one from

Turtles in Austin

2005-07-29T22:00:00.000-07:00

Texans believe in air conditioning. I should rephrase that: there exist at least some Texans who believe in air conditioning at least part of the time. Presumably one of those Texans is involved in the administration of the Austin convention center. It was hot and humid outside, but I wished more than once that I'd paid closer attention to the advice to bring a blazer.

In a Barrel

2005-07-23T13:08:00.000-07:00

Searching for LISP-based implementations of different programming languages is a task akin to shooting a mixture of metaphors and pre-hatched chickens in a barrel. Let's see who Google brings to this post based on that sentence. I think I've written already that next semester I'll be the GSI (graduate student instructor -- a UC-ism for teaching assistant) for the local

Its Own Worst Enemy

2005-07-22T12:39:00.000-07:00

I like Best Software Writing I (ed Joel Spolsky) more the more I read. One of the things I like about it is that most of the selected pieces are available in electronic form, so that I can point people to them without saying Oh, but you need to buy the book to see it. That said, this is a book worth checking out, even if you're not a software developer. I just finished reading

Pen trip

2005-07-21T17:28:00.000-07:00

I will fly to Austin on Sunday so that I can give a talk on MEMS resonator simulation on Monday morning at the computational mechanics conference. I'll be back in Berkeley come Friday, and that will be it for my summer travels. I'd originally planned to go home at the start of August, but I'm tired of travel, and want to spend the rest of my summer enjoying my own bed and my own

PowerBook accelerometers

2005-07-19T17:20:00.000-07:00

The Sudden Motion Sensor (SMS) on the PowerBook is used to turn off the hard drive in the case of sudden acceleratins (like those that occur when you drop the computer, for instance). The ThinkPads have a similar system. The device is almost certainly using a microelectromechanical system (MEMS) sensor, probably one of the ADXL series from Analog Devices -- the same types of

On Anonymity

2005-07-18T15:12:00.000-07:00

Have you seen the old New Yorker cartoon in which two dogs are sitting at a computer, and one is telling the other On the Internet, nobody knows your a dog? Hmm. Let me share some reasons why online anonymity is a little more complicated than that. First, let's dispense with the obvious. If you write a large body of information drawn from your personal experiences, then

Reading list

2005-07-17T14:35:00.000-07:00

I have not read the new Harry Potter book. Even if I had, I doubt I'd have much to say about it. Good book reviews either alert the reader to a book he may not otherwise have noticed or chosen to read, or they put the book under review into a wider perspective, or they become a sort of essay draped on the structure of the contents of a book. For a book so heralded as Rowling's

From New Orleans

2005-07-13T22:42:00.000-07:00

My talk went fine, and was far from the most technically interesting thing I've seen or heard while hear. The weather is muggy, the food is good, the coffee and tea are respectively mediocre and dreadful. Tensor the Laptop has continued to function beautifully, even during the required night-before slide editing session. It's been fun, but I'm glad to head home tomorrow. And I'll be

MEX and OS X

2005-07-09T11:55:00.000-07:00

If it isn't clear by now, half the point of these last few points is to record quirks of architectural quirks as I encounter them while re-building my software under OS X. This is useful for me (it's sometimes easier for me to search old blog entries than it is to search through my old research notebooks); it may or may not also be useful for the people who stumble in here on the

Fixing things

2005-07-08T21:05:00.000-07:00

HiQLab now compiles and runs on the PowerBook. The problem, as it turns out, had to do with a compiler issue in the Xcode version of gcc-4. Somehow the default destructor was getting bungled for classes that contained STL vectors. In a way, I'm glad that this happened, because it meant that I was forced to do something I'd intended to do for a while anyhow (default destructors have

It's alive!

2005-07-08T00:06:00.000-07:00

I'm typing this on the new PowerBook. I had good timing -- the backlight on the Thinkpad simply wouldn't come on after I returned to the office this afternoon, and so it is attached to an external monitor. I'm in the process of transferring my files over to the Mac. It's going smoothly at the Mac end, less smoothly at the Thinkpad end. This is perhaps to be expected. I'm impressed

Hamming Talk

2005-07-06T10:09:00.000-07:00

Courtesy Revolutionibus, I spent some time reading Hamming's talk on You and Your Research. There's a lot of good stuff in there -- and I think it's still good stuff even if you're not planning a career in research.

Code Tomography

2005-07-06T09:27:00.000-07:00

This is part three in a planned five-part sequence on some interesting applications of linear algebra to tomography for computer networks, programs, and a yet-to-be-decided physical example. Today: how to get more utility from conventional code coverage tools by analyzing a matrix that traces out the different execution paths exercised by a test suite. If you compile programs

Pitfalls in Computation

2005-07-06T09:26:00.000-07:00

From the introduction to Pitfalls in Computation, or Why a Math Book Isn't Enough, by George Forsythe (Stanford CS Tech Report 147, 1970): Why do students take mathematics in college and university? I see two reasons: (i) To learn the structure of mathematics itself, because they find it interesting. (ii) To apply mathematics to the solution of problems they expect to

Apple of my i

2005-07-05T19:08:00.000-07:00

I ordered a 15 inch PowerBook today. Sadly, it turns out that the right grant to pay for this is called my savings account; fortunately, I found out in time to get the new machine before my next trip. It should arrive in the next day or two. I'm excited. I'd better start thinking of a name... I played on a Commodore 64 when I was a kid, then moved to PCs. One of my best friends

Network Tomography

2005-07-05T11:01:00.000-07:00

This is part two in a planned five-part sequence on some interesting applications of linear algebra to tomography for computer networks, programs, and a yet-to-be-decided physical example. Today: understanding link properties from end-to-end measurements. I'm going to start with the same setup that we had yesterday. We have n computers attached to the Internet, and they need to

Network Monitoring

2005-07-04T13:31:00.000-07:00

This is part one of a planned five-part sequence. This article and the next are on network tomography; then there will be two articles on coverage testing and code tomography, a simple application of the same ideas to a completely different problem; and the fourth article will be on a physical tomography problem with the same flavor (I have two in mind, but haven't yet decided which

Book Review

2005-07-04T13:28:00.000-07:00

In flipping through the June 2004 issue of SIAM Review (vol 46, no 2), I happened to re-read Emma Previato's review of the CRC Concise Encyclopedia of Mathematics. If you have electronic access to the SIAM journals (through a university library, perhaps), go read it for yourself! It's a wonderful example of what a book review can be.

Testing Euler

2005-07-03T20:31:00.000-07:00

If you can see this, then jsMath is working as promised: e^{\pi i} + 1 = 0 UPDATE: It works! At least, it works for me. If you're reading this and not seeing Euler's formula, please let me know. And expect to see more mathematics from me, now that I can actually typeset it.

Miscellaneous

2005-07-02T21:16:00.000-07:00

Go read Keith Devlin's article on Staying the Course. It has nothing to do with the rest of what I'm going to write, and a great deal to do with my recent day-to-day life. I'm still enjoying the novelty of glasses that allow me to read the subtitles and authors from the spines of my books without getting out of my chair; I'm getting used to having a cell phone; and I sincerely

College: Freshman, Sophomore

2005-06-27T12:47:00.000-07:00

I divide my undergraduate years into two distinct periods. My living environment, course load, and social interactions all changed between my first two years and my last two years of college. I changed, too. During my freshman and sophomore years, I lived in Denton Hall, one of the massive high-rise dormitories on the UM campus. To be specific, I lived in 6107 Denton Hall. I

Duality and Tensors

2005-06-23T14:31:00.000-07:00

A little while ago, I wrote about the idea of dual spaces, and how the idea of a dual vector could be represented directly in languages like LISP and Lua, where functions can be treated like any other sort of data. If you remember that entry (or if your page down button works), you'll know that for any real vector space V the dual space V* is the space of all linear functions from

High School

2005-06-18T11:30:00.000-07:00

I visited the campus book store today. I got the book that I was wanted, Becker's Electromagnetic Fields and Interactions, which now sits comfortably next to my copy of Jackson's book. I'll have to return the earlier book by Abraham and Becker on Monday. I was also pleasantly surprised to discover that Electromagnetic Fields is bound together with a second volume, Quantum Theory

Three Stories

2005-06-15T13:01:00.000-07:00

Stay Hungry. Stay Foolish.

A Matter of Tone

2005-06-14T12:28:00.000-07:00

Usually when I receive requests for help with software, they are neutrally phrased. Sometimes, though, they are incomprehensible, impolite, or both. It's hard to do much about the incomprehensible questions, except to reply with an e-mail that might be briefly summarized as eh, wozzat?; but for the deliberately rude or insulting requests, I sometimes will suggest some ways to get

Pines and Signs

2005-06-13T11:21:00.000-07:00

I got my new glasses yesterday morning, and since then I've been admiring the world's sharp edges. My vision isn't terrible, but I am more myopic than I was when I got my last pair of glasses (eight years ago?). I'd noticed in the past couple years that I was having increasing difficulty reading street signs and seminar slides, but I did not notice that the needles on the upper

Programming and Duality

2005-06-11T23:20:00.000-07:00

Vector spaces are like potato chips. You cannot have only one. W. Kahan One of the key ideas in linear algebra is that of a dual space. If V is a finite-dimensional real vector space, then the dual space V* consists of all linear functions from V into the real numbers. A function from V into the real numbers is sometimes called a functional on V, so we also sometimes say

Physics of Star Wars

2005-06-10T19:00:00.000-07:00

Almost exactly a week ago, I got around to seeing Revenge of the Sith. I think I would rather have seen Hero on the big screen and waited to see the last Star Wars installment on the small screen, but it was entertaining nonetheless. Even more entertaining, at least for me, where my falling-asleep thoughts about the movie over the past several evenings, which I will share with you

Piano Rain

2005-06-08T22:43:00.000-07:00

I do not know the name of the piano piece playing on the radio now, but it is a good accompaniment to the tap of rain on the roof and the occasional swish of a car on the wet pavement. It is a sound I associate with summer rains in Maryland; but for today there is rain in Berkeley as well. This evening I walked to a cafe, and from there to the office, and from there back home. Low

Cartoons and math jokes

2005-06-07T17:42:00.000-07:00

I've heard this one already. But I chuckled nonetheless.

More Books

2005-06-06T14:35:00.001-07:00

Recently, I've taken less time for light reading than I sometimes do. Oh, I had a grand time with Truesdell's Idiot's Fugitive Essays on Science, and if you can find a library copy, I encourage you to enjoy it as well. But I didn't read much while I was traveling. I did read A Short History of Nearly Everything by Bill Bryson, and I recommend it -- Bryson is funny, and manages

Bus Stop

2005-06-06T14:35:00.000-07:00

While at the bus stop on Saturday, I queued up behind a large group of Chinese travelers (they were speaking to each other in Mandarin, at least), most of whom took an awfully long time getting on the bus. I'm not so sure why the rest of them took so long, but I got to witness the whole interaction when the woman in front of me paid her fare. She tried to put in just a dollar, and

Things Learned

2005-06-01T12:31:00.000-07:00

I learned last week that it's past time for new glasses. So I'm getting an eye exam today, and will proceed from there. In preparation for walking around half-blinded by dilated pupils, I invested in a pair of sunglasses this morning. There are some people who manage to look classy in sunglasses. For myself, I think goofy is a better adjective. I knew that before, but it's good

Pondering Plurals

2005-05-30T11:32:00.000-07:00

The plural of house may be houses, But the plural of mouse isn't mouses. Is some sense of what's nice, Unlike rodents or lice, Why we do not say spice, but say spouses?

The Things We Do

2005-05-29T18:29:00.000-07:00

I'm back. I spent one week at the Householder meeting in Pennsylvania, where I spoke with interesting people and with them mourned the lack of network access and good coffee. My talk went fine, and I listened to various other talks, some good and some not-so-good, but (as usual) all the most useful work and conversation happened between sessions, or in the hall outside the sessions.

Travels

2005-05-21T19:04:00.000-07:00

I will probably be in Boston from May 27 through June 1. My original reason for going there has evaporated, but because of how it fits in with other travel, it makes little sense for me not to spend at least a couple days in Boston regardless. Any suggestions for what I should do while there? The workshop this past week was enlightening. Most of the attendees had backgrounds

Mathematics and Science

2005-05-15T22:26:00.000-07:00

From Saturday's reading: In the main, it is the applied scientists who call for numbers, numbers, numbers. Although the layman conceives mathematics as being the science of numbers, few mathematicians agree, and most of modern mathematics gives to numbers a role at best ancillary or illustrative in the development of concepts. Mathematics is the science of precise relations.

Tensor

2005-05-14T12:44:00.000-07:00

When I first heard the word tensor toward the end of high school, I liked the sound of it. But it took me until a couple years into graduate school to get to my current understanding. It's not so uncommon for students to come into college with a bit of formal mathematical coursework beyond basic calculus. In my case, I had a second semester calculus course and some differential

Ha

2005-05-11T15:58:00.000-07:00

Vader blog? Excellent.

Idiot's Fugitive Essays

2005-05-11T15:12:00.001-07:00

Clifford Truesdell was interested not only in mechanics, but also in the history and philosophy of science. Knowing this, I looked up the list of books he wrote. My intention was to find a reference that might tell me a little about the history of Riemannian ideas in continuum mechanics. I didn't exactly find what I was looking for; what I found instead was An Idiot's Fugitive

City CarShare

2005-05-09T16:12:00.000-07:00

I used the City CarShare program for the first time today. As the name suggests, this is a program for sharing cars, a sort of non-profit micro-rental program. There are pods of cars scattered across the East Bay and the South Bay, usually close to public transportation so it's possible to just take the car for a final leg of a trip after taking public transit. I don't like

Computational Fest

2005-05-09T16:11:00.000-07:00

The Berkeley-Stanford Computational Mechanics Fest took place this Saturday. Twelve professors, some from Stanford and some from Berkeley, spoke on numerical models of various problems in mechanics; the topics included things phenomenta such as sedimentation, ductile fracture, dislocation dynamics, granular flows, and anisotropic surface friction. I thought the talks were

Quick Explanations

2005-05-06T15:34:00.000-07:00

What makes a good quick explanation? I can think of several possible criteria. The most obvious are that it should be quick and it should explain something. A lecture is, to most people, not quick; and a sound bite is, as often as not, not very explanatory. Political speeches, marketing pitches, and other such beasts are neither quick nor explanatory, It's easy to measure

Cinco de Mayo

2005-05-05T13:19:00.001-07:00

Happy May 5! Today is not actually Mexican independence day, but it is the anniversary of a major battle between Mexico and France. Popular confusion over the reason for the celebration won't keep any number of people from celebrating, of course. The weather, on the other hand, might be an impediment. It's raining here. It's also sufficiently close to the end of the semester that a large

Baa-ck

2005-05-05T13:19:00.000-07:00

... said the sheep to the masseuse. I think this is a good time to end my blogging hiatus. Posting will be light at times, particularly during the weeks when I'm on travel or when I'm making good progress on writing my thesis. But there will be posts. I may even get around to adding a blogroll.

Blogging Hiatus

2005-04-11T12:51:00.000-07:00

I haven't been posting much recently. I'm busy, but not more so than usual (for me or for anyone else). I've been busy writing, be it ever so slowly, documentation for my code, papers for publication, and a thesis; and I've been busy reading, and doing mathematics, and programming. But this blog has been largely independent of those things in the past; so why so few posts?

Recent reading

2005-04-08T14:43:00.000-07:00

I've had a great week for pondering and reading, some of which is reflected in my seminar talk on complex symmetric matrices this Wednesday, and some of which may show up in more detail later. Want to know what a Prony series is? What an Evans function is? What the Correspondence Principle is? Why mixed precision arithmetic is a Good Thing for even simple computations? Okay,

Electronic Paper

2005-04-08T13:43:00.000-07:00

Remember the paperless office? The name dates the idea: if it was conceived in the past decade, it would have been the e-office, or if Apple were involved it might have been the iOffice. However it's called, the idea hasn't been realized, and for good reason. Electronic document management still has a ways to go. Display I refuse to read books on CRT monitors. When I

Not Written

2005-04-04T13:18:00.000-07:00

In the past week, I wrote one entry on a quote from William James. In the past week, I wrote three letters, about twenty pages of miscellaney in my log/research notebook, and more e-mails than were probably necessary. I swapped a new cartridge into my fountain pen, and wrote it dry again within five days. I renewed my library books, and recommended to someone else that they might

Sifting Studies

2005-04-01T14:58:00.000-08:00

You can give humanistic value to almost anything by teaching it historically. Geology, economics, mechanics are humanities when taught with reference to the successive achievements of the geniuses to which these sciences owe their being. Not taught thus, literature remains grammar, art a catalogue, history a list of dates, and natural science a sheet of formulas and weights and

Empire Star

2005-03-28T12:08:00.000-08:00

... Once she rather surprised both Jo and me by saying during one lesson when he seemed particularly recalcitrant and demanded another reason for why he had to improve his Interling: Besides, think how tiring your clumsy speech will be to your readers. My what? He had already, with great difficulty, mastered his final consonants. You have undertaken an enterprise of great pith

Some Sums

2005-03-25T11:07:00.000-08:00

Probably everyone reading this has heard the (likely apocryphal) story of Gauss being given sums as a school exercise. At least, I think it was Gauss. Anyhow, the story goes that the teacher told the class to sum the numbers from one to a hundred, and Gauss came back with the answer a few moments later. The numbers from one to a hundred can be grouped into 50 pairs, each of which

More Writing Comments

2005-03-24T14:30:00.000-08:00

Good writing is to bad writing as idiomatic usage is to idiotic usage.

Culture of Life

2005-03-24T13:57:00.000-08:00

Does anyone else think of Petri dishes when they hear the phrase culture of life?

Absent-Mindedness, Part Deux

2005-03-24T13:48:00.000-08:00

Pete has things to say about my comments on absent-mindedness. In fact, Pete has many things to say about the topic. I think most of them are more interesting than my original comments, actually.

Absent-Minded Thoughts

2005-03-23T11:03:00.000-08:00

Do you ever find yourself staring at a written word and thinking how strange it looks on the page? Or do you hear a clearly-spoken English sentence which you're unable to immediately process? What about looking for glasses while they're perched on your nose -- or sitting in clear sight on the desk in front of you? All these things happen to me regularly: at least once a week for

Ramanujan

2005-03-22T16:50:00.000-08:00

I just read a Slashdot post in which Ramanujan is referred to is some Indian math guy. I regard this as about the same as calling Einstein some German physics guy.

Composing My Thoughts

2005-03-22T11:46:00.000-08:00

This weekend the latter half of my last Amazon order came. I now have a copy of Mathematical Writing (Knuth) and Approximation Theory (Cheney). The former was much less intriguing than I thought it would be; but Teacher in America (Barzun) was part of the same order, and it was better than I expected, so in the mean I think I was pleasantly surprised. Anyhow, most of Mathematical

Movies and China

2005-03-22T11:45:00.001-08:00

The Elephant Pharmacy on Shattuck Avenue is a fancy sort of place, and most of the things it sells are expensive. But the store also rents DVDs, and the DVD rentals are a dollar a night. I only discovered how cheap the rentals were this weekend, and I perhaps went overboard by spending four dollars to rent Once Upon a Time in China, Iron and Silk, Harry Potter and the Prisoner of

Saturday Dinner

2005-03-22T11:45:00.000-08:00

I had friends over for dinner on Saturday. It's the first time I've invited people over in a bit over a month, and in that month I've had several good meals with friends: we made gyoza once, and we had a chicken dinner with all the trimmings another time. So I felt it was my turn. We started with bread and tomatoes, steamed asparagus, and salad. Winnie handled the asparagus,

Cheeseboard

2005-03-22T10:42:00.000-08:00

Late Saturday morning, Winnie and I walked to the Cheeseboard for bread. I can't see how any other bakery within a mile stays in business, said Winnie; I replied that other bakeries stay open longer. Besides, baked goods go well with coffee, and any city that can support as many cafes as Berkeley supports must also be able to support more than one bakery. The Cheeseboard is a

To Blog

2005-03-18T13:46:00.000-08:00

I can verb any noun you give me, said my undergrad linguistics teacher. She may have exaggerated, since I'm not sure how to use sky or desk as verbs. Still, I can think of many terms that prove her point: to email, to google, to code, to spam, to TeX, and to blog. People create new tools and feel dissatisfied with the current vocabulary to describe how the tools are used, and

Happy pi day!

2005-03-14T14:33:00.000-08:00

It's 3.14, and there's mathematical graffiti for pi day all over the sidewalks in front of Soda Hall. Whee!

Dice

2005-03-10T12:43:00.000-08:00

If I roll two dice and I take the sum, I'm more likely to roll seven than to roll two. But is it possible that I could weight a pair of dice so that all possible sums are equally probable? If you like mathematical puzzles, I strongly encourage you to stop here and play with this problem for a while. It's a fun one, and there are all sorts of generalizations. What if I use more

Books Again

2005-03-09T12:52:00.000-08:00

I haven't written anything for a while about the books I've been reading. I've gone through a batch of good ones in the past two weeks or so, and if I say nothing about them now, I may forget. Isaac Newton (James Gleick) I like Gleick's writing. I know I've written before about his book Faster, and I think I've written about Chaos, a book I read in high school. Isaac Newton is

Programming Languages

2005-03-07T19:25:00.000-08:00

I use several programming languages day-to-day, and a few more languages occasionally. I have a passing familiarity with several more languages that I uses rarely, as are most students with recent computer science degrees. They are our basic tools. They are so basic that I sometimes assume everyone knows about them, until I get brought up short with a question. What's a lambda

How Long?

2005-03-03T21:12:00.000-08:00

Know this feeling?

Structure and Speed

2005-03-03T20:03:00.000-08:00

Hit a tuning fork on a table and it will ring -- for a while. Over time, the ringing will gradually decay away, its energy spent. Some of the energy of resonance goes into the air; some of it gets absorbed into motion of defects in the metal; and some of it will be absorbed by the hand that holds the tuning fork. If you have a very tiny tuning fork made out of a nice material like

Representation

2005-03-02T14:41:00.000-08:00

The Mythical Man Month: Essays on Software Engineering (Brooks), like Elements of Style (Strunk and White), has a proud place on my shelves. Brooks book is now thirty years old; I have the twentieth anniversary edition, which is still in print. The technical references are dated; the ideas about writing, design, and engineering organization remain fresh. The last section of the

Library Loan

2005-02-24T20:42:00.000-08:00

I ran into a colleague on my way back from the engineering library this afternoon, and we had a conversation that went something like this: It's strange to see you carrying that book. I'd forgotten that I'd returned it to the library, and I was used to seeing it on my shelf. I figured that was where it was; I've been checking on and off for a while. It has been on my shelf for

Paper

2005-02-24T20:25:00.000-08:00

Sometimes paper works better. Courtesy LifeHacker.

Shipped!

2005-02-23T20:42:00.000-08:00

This is the third attempt to draft this entry. The first two times, I was cut short when my computer locked up; it does this from time to time -- due, I think, to a known bug in the graphics hardware -- but not so often that I'm willing to get rid of it and get a new computer. There are days, though, when I'm tempted to do just that. This laptop is sturdy, and has done well for the

Miscellaneous T

2005-02-20T14:17:00.000-08:00

Does this sound familiar? I may have to watch a little more television. Okay, I'll probably forget; but I'm pleased by the idea that someone is casting a mathematician in a role that is not insane or doofy. Thinking of public awareness of mathematics, I just saw the poster for Math Awareness Month 2005. Pretty pictures! I mentioned a while ago two articles on the

Elderflower and Spinach

2005-02-20T12:45:00.000-08:00

It rained yesterday. Our original plan, to walk around Chinatown and watch New Year festivities, washed away with the rain. Instead, we went to have lunch at Ikea. I've never visited an Ikea before, though I hear about it often. I shared a plate of Swedish meatballs, which were good, and had a croissant sandwich, which was stale. The restaurant was having a Lunar New Year

Play

2005-02-17T23:24:00.000-08:00

The past month or so has been busy. Tomorrow afternoon, I'll be giving a tutorial on my resonator simulation code, and -- if the kami that govern my interactions with Office feel benevolent -- I will quickly finish the last bits of the slide, poster, and report that are due at the BSAC office for the upcoming industrial advisory board meeting. Then I'll have some breathing room for