|The Universe of Discourse|
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Sat, 08 Feb 2014
I wrote some time ago about Moonpig's use of GUIDs: every significant object was given a unique ID. I said that this was a useful strategy I had only learned from Rik, and I was surprised to see how many previously tricky programming problems became simpler once the GUIDs were available. Some of these tricky problems are artifacts of Perl's somewhat limited implementation of hashes; hash keys must be strings, and the GUID gives you an instantaneous answer to any question about what the keys should be.
But it reminds me of a similar maxim which I was thinking about just yesterday: Every table in a relational database should have a record ID field. It often happens that I am designing some table and there is no obvious need for such a field. I now always put one in anyway, having long ago learned that I will inevitably want it for something.
Most recently I was building a table to record which web pages were being currently visited by which users. A record in the table is naturally identified by the pair of user ID and page URL; it is not clear that it needs any further keys.
But I put in a record ID anyway, because my practice is to always put in a record ID, and sure enough, within a few hours I was glad it was there. The program I was writing has not yet needed to use the record IDs. But to test the program I needed to insert and manipulate some test records, and it was much easier to write this:
If you ever end up with two objects in the program that represesent record sets and you need to merge or intersect them synthetically, having the record ID numbers automatically attached to the records makes this quite trivial, whereas if you don't have them it is a pain in the butt. You should never be in such a situation, perhaps, but stranger things have happened. Just yesterday I found myself writing
which nobody should have to do either, and yet there I was. Sometimes programming can be a dirty business.
During the bootstrapping of the user-url table project some records
with bad URLs were inserted by buggy code, and I needed to remove
them. The URLs all ended in
So the rule is: giving things ID numbers should be the default, because they are generally useful, like handles you can use to pick things up with. You need a good reason to omit them.
Tue, 05 Oct 2010
Tufte says "Here five colors report, almost by happenstance, only five pieces of data (since the division within each year adds to 100 percent). This may well be the worst graphic ever to find its way into print."
Unfortunately the standards of the Internet can be even lower than those of print, as exhibited by this infographic, produced by Pingdom:
Chapter 6 of Tufte's book, "Data-Ink Maximization and Graphical Design", explores the exercise of erasing all the ink from an infographic that does not perform the function of communicating data. If we were to take this a little farther, and replace the original 80,265-byte graphic file with the 32 bytes of numeric data that it was designed to communicate, we might conclude that the image contained an astounding 99.96% chartjunk.
Wed, 06 Feb 2008
Phil Rodgers has pointed out that a "physique" is not an emetic, as I thought, but a laxative.
Are there any among you who doubt that Bruce Schneier can shoot sluggbullets out of his ass? Let the unbelievers beware!
Tue, 05 Feb 2008
He told us a very handsome passage of the King's sending him his message ... in a sluggbullet, being writ in cypher, and wrapped up in lead and swallowed. So the messenger come to my Lord and told him he had a message from the King, but it was yet in his belly; so they did give him some physique, and out it come.Sure, Bruce Schneier can mount chosen-ciphertext attacks without even choosing a ciphertext. But dare he swallow a "sluggbullet" and bring it up again to be read?
Silly me. Bruce Schneier can probably cough up a sluggbullet without swallowing one beforehand.
[ Addendum 20080205: A correction. ]
Sun, 30 Apr 2006
Abbreviations in medieval manuscripts
Diacritical marks have been used to abbreviate printed words ever since Gutenberg, and early English printers adopted the same conventions that Gutenberg used for Latin (a trick he picked up from medieval scribes.)Shortly afterward I realized that I have some reproductions of illuminated manuscripts—they're hanging in the bathroom, so I see them every day—and could actually see this for myself. This one is my favorite:
I had never been able to decipher the Latin text, but I had never tried very hard before. So I stared at it for a few minutes. Here is the inscription itself, in case you'd like to play along at home:
After quite a lot of staring, I came to two conclusions:
Eventually I did what I should have done in the first place and plugged mella locustis into Google. The result was quite conclusive. The words here are from a very famous hymn about John the Baptist, attributed to Paulus Diaconus (c. 720 -799). The hymn is in three parts, and this is the beginning of the second part. The words here are:
Antra deserti teneris sub annisI've colored the text here to match the text in the manuscript. Stuff in gray in the first verse is omitted from the manuscript; I do not know why. A copying error, perhaps? Or a change in the words?
The amount of abbreviation here is just amazing. In the first line, deserti is abbreviated deseti, and the s and the e are all squashed together, sub is abbreviated sb, annus is abbreviated ãnis, civium is abbreviated civiû and is illegible anyway, because the letters all look alike, as in Russian cursive. (I have a similar problem with cui on the third line.)
On the second line, artubus is written artub3; Hoefler had already pointed out to me that the 3 was a common notation in 16th-century printing. On the third line, pastum is written pa'tû, where the wiggly mark between the a and the t denotes an elided s. Or perhaps the scribe left it out by mistake and then went back to squeeze it in later.
Probably the most amazing abbreviations in the whole thing are in the fourth line. (I wonder if perhaps the scribe realized he was running out of room and wanted to squeeze in as much as possible.) The word caeteri is abbreviated to ceti, tantum to tm, and praesago to p'sago. (Also note uatû, which is an abbreviation for vatum; I had been wondering for some time what Uatu had to do with it.)
There are a number of other typographical features of interest. The third word in the second line is apparently hirtum. The hi in the manuscript is written as a sort of a V-shape. The r in corde on the fourth line (and elsewhere) is a form that was once common, but is now obsolete.
This hymn, by the way, is the one that gives us the names do, re, mi, fa, so, la, si for the notes of the major scale. The first part of the hymn begins:
Ut queant laxis resonare fibris"Ut" was later changed to "do" because "do" is open while "ut" is closed. Scholars speculate that the name "si" was chosen because it is the initials of the words in the final line.
The thing about the locusts and wild honey reminds me of something else. I was once on a business trip to Ottawa and found that there was a French Bible in my hotel room. And I discovered that, although I cannot read French, I could read the Bible in French, because I already knew what it was going to say. So I lay in bed and read the French Bible and enjoyed the rather strange sensation of being able to pretend to myself to be able to read French.
Two points struck me at the time. One was that when I read "Dieu dit: Que la lumière soit!" ("God said, 'Let there be light'") my instant reaction was to laugh at how absurd it was to suggest that God had spoken French when He created the universe. It's like that Reader's Digest joke about the guy who thinks the Spanish-speaking folks are silly for talking to the squirrels in the park in Spanish, because squirrels don't speak Spanish. I didn't know I had that in me, but there I was, laughing at the silly idea of God saying "Que la lumière soit!" You know, I still find it silly.
The other memorable occurrence was a little less embarrassing. The part in Matthew (excuse me; "Matthieu") about John the Baptist eating locusts and wild honey was "Il se nourrissait de sauterelles et de miel sauvage." I was impressed at how tasty it sounded, in French. It is not hard to imagine going into an expensive restaurant and ordering sauterelles et de miel sauvage off the menu. I concluded that food always sounds better in French, at least to an anglophone like me.
Wed, 12 Apr 2006
Diacritics and horseheads
I wrote to Jonathan Hoefler to ask about this. Jonathan Hoefler is one of the principals of the typography firm Hoefler & Frere-Jones, and his mind is a vast storehouse of typographical history and arcana. I was sure M. Hoefler would know about the tildes, and would have something interesting to say about them, and I was not disappointed:
Diacritical marks have been used to abbreviate printed words ever since Gutenberg, and early English printers adopted the same conventions that Gutenberg used for Latin (a trick he picked up from medieval scribes.) As you say, tildes and macrons (and circles and odder things still) were used to mark the elision of letters or entire word parts: the "Rx" ligature that we know from prescriptions (Lat. 'recipe') was also used as shorthand for the "-rum" Latin ending, among other things. The French circumflex is a holdover from the same tradition, as it once the absence of a succeeding 's' ("hôpital" for "hospital", etc.) All of these were compositors' tricks to help in the justification of an entire paragraph, something that was considerably easier in the days before standard spelling and orthography!The surprising diacritical marks don't exhaust the oddities of 16th-century fonts. Hoefler & Frere-Jones have designed a font, English Textura, that is similar to the blackletter font that Recorde's book was printed in; they did this by borrowing characters from actual 16th-century documents. The documents contain all sorts of interesting typographic features that are no longer used; look at the bottom rows of this sample of English Textura for examples:
Hoefler mentions that "you'll see Ms and Ns with lightning bolts above, which presumably mark the absence of a following vowel," and that even he hasn't deciphered all the odd diacritics and ligatures that were in use then, which he and Frere-Jones included in the font anyway.
I should mention, in case it isn't clear, that justification of paragraphs is not merely a cosmetic feature. If you are a printer in 1577, you are laying out metal types into a square frame, and if the frame isn't completely filled, the types will fall out when you turn it over. In particular, you must make each line of each paragraph fully extend from left to right, or it will be unprintable. The Renaissance printers must have to justify the text somehow. One way to do this is by inserting blank spaces of suitable lengths between the words of each line; I asked M. Hoefler why the Renaissance printers didn't just use blank space, and he replied:
They did that as well, but I think the general principle (which endures) is that wordspacing really isn't as flexible as you'd hope -- "rivers" are the effect of adjacent lines being overjustified, and they really interrupt reading. Even with today's very sophisticated H&J [Hyphenation and Justification] algorithms -- some of which can even scale the actual dimensions of letterforms in order to improve copyfit -- the chief ingredient in good H&J controlling the number of letters per line. Contemporary newspapers do this through aggressive hyphenation; their forbears did it through colorful spelling. (Although any headline with the word "Prez" suggests that this tradition lives on.)You'll note that The Whetstone of Witte is also agressively hyphenated:
I think Marshall McLuhan said something about the new media cannibalizing the old, and although I'm not sure what he meant (if he did say that) I don't think it matters much, because the phrase so perfectly encapsulates the way new information technologies tend to adopt the obsolete forms of the technologies they replace. I've been collecting examples of this for a few years. In the early days of the web, there was a web dictionary which would lay out the pages just like a real dictionary, with an unreadably tiny font, page breaks in inconvenient places, and "next page" and "previous page" buttons at the bottom. The tiny font was bad enough, but the "next page" buttons just killed me. I wanted to redesign the application with another button that you could press if you wanted to simulate what happens when you read the dictionary in the bathtub and drop it in the water by mistake.
I call these phenomena "horseheads", after the false horse heads that were mounted on the hoods of old automobiles, which still survive as in vestigial form as hood ornaments. My favorite horsehead is a Citibank ATM design from around 1987 or so. The old ATMs, which the new design was replacing, had green phosphor display, about 20×40 characters, four menu buttons down the side, and a telephone-style keypad with ten digits and # and * signs. The new ATM had no buttons. Instead, it had a color touch-sensitive screen that was used to display a touch-sensitive picture of four menu buttons down the side, and, when appropriate, a telephone-style keypad with ten digits and # and * signs.
[ Addendum 20120611: The
term "skeuomorph" has recently become popular to describe this
The following passage appears on page 3:
How strange a thing this art of writing did seem at its first invention, we may guess by the late discovered Americans, who were amazed to see men converse with books, and could scarce make themselves believe that a paper could speak; especially, when after all their attention and listening to any writing . . . they could never perceive any words or sound to proceed from it.I find this plausible, since as far as I know none of the aboriginal peoples in the part of the world colonized by the English had writing, and because writing does seem strange and astonishing to me. Also, it seems that many other people found it so. For example, in The Origin of Consciousness in the Breakdown of the Bicameral Mind (which I am sure will turn up here again) Jaynes quotes examples of letters written by the Assyrians. The standard form of such letters was to address the messenger who delivered them, like this:
To Babu-aha-iddina, governor of Eridu, say thus:This form arose originally because the recipient was unable to read, and the messages were sent orally. A messenger would memorize the message at the source, and recite it from memory at the destination. So the message is written as an instruction to the messenger who would deliver it: "To Babu-aha-iddina, say thus..." and ends with a closing statement, also to be made by the messenger, that "so says Tukulti-Ninurta." But in later times, the form was still followed even when both sender and recipient were literate, and then it becomes an instruction to the letter itself to "say thus".
The idea that it is the letter itself that speaks seems to be a natural one. Wilkins tells a story of an Indian who is sent to deliver a letter and a basket of figs to a man in the next village. The messenger ate half the figs on the way, and was surprised to be found out upon his arrival when the quantity of figs he delivered did not match the quantity described in the letter. He responded by cursing the letter as a false and lying witness. On the next trip, he was careful to bury the letter under a rock while he ate the figs, so that it would not be able to accuse him when it was delivered.
Children first learn to read by pronouncing the words aloud and hearing them; when they hear, they understand. Hearing is much easier than reading, and I think this is one reason why people like to attend lecture classes instead of just reading the book. People who "move their lips when they read" are widely ridiculed. But reading aloud is a good strategy for anyone faced with difficult material. When I can't make sense of a difficult paragraph, especially a long and confused one, I always back up and try reading it aloud, and this often resolves the difficulty. Even when I have forgotten the words at the beginning by the time I get to the end, I find that I still retain the sense of them. Reading aloud is also a good exercise for writers. If you read aloud what you wrote, you are much more likely to notice when it doesn't make sense. If you are too self-conscious to read aloud, or if the sign says QUIET PLEASE, try subvocalizing; it is still a big help.
Some kinds of literature should always be read aloud. Poetry, of course. If it is good poetry, it loses a lot of its value when read silently. I find that humor also loses its savor for me when I read it non-orally. When I first read Fear and Loathing in Las Vegas myself, I thought it was just stupid. When I heard James Woodyatt read it aloud, it was riotously funny. Lorrie and I found that Louise Erdrich's stories and novels, which can seem unrelievedly depressing when you read them alone, when read aloud became rich, complex, funny, sometimes bitter, sometimes joyful, and often sad—but never depressing.
Someone once told me that some famous scholar, I think perhaps Thomas Aquinas [ addendum: it was Ambrose; see below ] was the only one of his contemporaries to read non-orally, that they were astonished at how the information would just fly from the book into his mind without his having to read it. Their failure to understand non-oral reading may be surprising today, when everyone is expected to do it. But I can remember making the same mistake myself. I was sitting on the floor, reading (aloud) the Sunday comics pages one evening, and I remarked that grown-ups did not actually read; they only looked at the pictures. My mother told me that they did read, but they did so silently. This was the first time I had encountered this idea, which I immediately adopted. I can't remember a time before I could read, but I do remember that occasion of my first silent reading.
[ Addendum 20120611: It turns out that there is a story collected by the Brothers Grimm, but unpublished, which recounts the lying letter story. It is "The Poor Boy in the Grave": "As he again was so extremely hungry and thirsty, he could not help it, and again ate two grapes. But first he took the letter out of the basket, put it under a stone and seated himself thereon in order that the letter might not see and betray him." ]
[ Addendum 20141202: The story about the famous scholar who astounded his contemporaries by reading silently was not Thomas Aquinas, as I said above, but Ambrose. Augustine, in his Confessions, says:
But when he was reading, his eye glided over the pages, and his heart searched out the sense, but his voice and tongue were at rest.I missed by eight hundred years! ]
Thu, 12 Jan 2006
Medieval Chinese typesetting technique
Here's a nice example. You may have heard that the Koreans and the Chinese had printing presses with movable type before Gutenberg invented it in Europe. How did they organize the types?
In Europe, there is no problem to solve. You have 26 different types for capital letters and 26 for small letters, so you make two type cases, each divided into 26 compartments. You put the capital letter types in the upper case and the small letter types in the lower case. (Hence the names "uppercase letter" and "lowercase letter".) You put some extra compartments into the cases for digits, punctuation symbols, and blank spaces. When you break down a page, you sort the types into the appropriate compartments. There are only about 100 different types, so whatever you do will be pretty easy.
However, if you are typesetting Chinese, you have a much bigger problem on your hands. You need to prepare several thousand types just for the common characters. You need to store them somehow, and when you are making up a page to be printed you need to find the required types efficiently. The page may require some rare characters, and you either need to have up to 30,000 rarely-used types made up in advance or some way to quickly make new types as needed. And you need a way to sort out the types and put them away in order when the page is complete.
(I'm sure some reader is itching to point out that Korean is written with a phonetic alphabet, hangul, which avoids the problem by having only 28 letters. But in fact that is wrong for two reasons. First, the layout of Korean writing requires that a type be made for each two- or three-letter syllable. And second, perhaps more to the point, moveable type presses were used in Korea before the invention of hangul, before Korean even had a written form. Movable type was invented in Korea around 1234 CE; hangul was first promulgated by Sejong the Great in 1443 or 1444. The first Korean moveable type presses were used to typeset documents in Chinese, which was the language of scholarship and culture in Korea until the 19th century.)
In fact, several different solutions were adopted. The earliest movable types in China were made of clay mixed with glue. These had the benefit of being cheap. Copper types were made later, but had two serious disadvantages. First, they were very expensive. And second, since much of their value could be recovered by melting them down, the government was always tempted to destroy them to recover the copper, which did indeed happen.
Wang Chen (王禎), in 1313, writes that the types were organized as follows: There were two circular bamboo tables, each seven feet across and with one leg in the middle; the tabletops were mounted on the legs so that they could rotate. One table was for common types and the other for the rare, one-off types. The top of each table was divided into eight sections, and in each section, types were arranged in their numerical order according to their listing in the Book of Rhymes, an early Chinese dictionary that organized the characters by their sounds.
To set the type for a page, the compositors would go through the proof and number each character with a code indicating its code number from the Book of Rhymes. One compositor would then read from the list of numbers while the other, perched on a seat between the two rotating tables, would select the types from the tables. Wang doesn't say, but one supposes that the compositors would first put the code numbers into increasing order before starting the search for the right types. This would have two benefits: First, it would enable a single pass to be made over the two tables, and second, if a certain character appeared multiple times on the page, it would allow all the types needed for that character to be picked up at once.
The types would then be inserted into the composition frame. If a character was needed for which there was no type, one was made on the spot. Wang Chen's types were made of wood. The character was carefully written on very thin paper, which was then pasted upside-down onto a blank type slug. A wood carver with a delicate chisel would then cut around the character into the wood.
(Source: Invention of printing in China and its spread westward. Thomas Francis Carter, 1925.)
In 1776 a great printing project was overseen by Jian Jin (Chin Ch'ien), also using wooden types. Jin left detailed instructions about how the whole thing was accomplished. By this time the Book of Rhymes had been superseded.
The Imperial K'ang Hsi Dictionary (K'ang-hsi tzu-tien or Kāngxī Zìdiǎn, 康熙字典), written between 1710 and 1716, was the gold standard for Chinese dictionaries at the time, and to some extent, still is, since it set the pattern for the organization of Chinese characters that is still followed today. If you go into a store and buy a Chinese dictionary (or a Chinese-English dictionary) that was published last week, its organization will be essentially the same as that of the Imperial K'ang Hsi Dictionary. Since readers may be unfamiliar with the organization of Chinese dictionaries, I will try to explain.
Characters are organized primarily by a "classifier", more usually called a "radical" today. The typical Chinese character incorporates some subcharacters. For example, the character for "bright" is clearly made up of the characters for "sun" and "moon"; the character for "sweat" is made up of "water" and "shield". (The "shield" part is not because of anything relating to a shield, but because it sounds like the word for "shield".) Part of each character is designated its radical. For "sweat", the radical is "water"; for "bright" it is "sun". How do you know that the radical for "bright" is "sun" and not "moon"? You just have to know.
What about characters that are not so clearly divisible? They have radicals too, some of which were arbitrarily designated long ago, and some of which were designated based on incorrect theories of etymology. So some of it is arbitrary. But all ordering of words is arbitrary to some extent or another. Why does "D" come before "N"? No reason; you just have to know. And if you have ever seen a first-grader trying to look up "scissors" in the dictionary, you know how difficult it can be. How do you know it has a "c"? You just have to know.
Anyway, a character has a radical, which you can usually guess in at most two or three tries if you don't already know it. There are probably a couple of hundred radicals in all, and they are ordered first by number of strokes, and then in an arbitrary but standard order among the ones with the same number of strokes. The characters in the dictionary are listed in order by their radical. Then, among all the characters with a particular radical, the characters are ordered by the number of strokes used in writing them, from least to most. This you can tell just by looking at the characters. Finally, among characters with the same number of strokes and the same radical, the order is arbitrary. But it is still standardized, because it is the order used by the Imperial K'ang Hsi Dictionary.
So if you want to look up some character like "sweat", you first identify the radical, which is "water", and has four strokes. You look in the radical index among the four-stroke radicals, of which there are no more than a couple dozen, until you find "water", and this refers you to the section of the dictionary where all the characters with the "water" radical are listed. You turn to this section, and look through it for the subsection for characters that have seven strokes. Among these characters, you search until you find the one you want.
This is the solution to the problem of devising an ordering for the characters in the dictionary. Since this ordering was (and is) well-known, Jin used it to organize his type cases. He writes:
Label and arrange twelve wooden cabinets according to the names of the twelve divisions of the Imperial K'ang Hsi Dictionary. The cabinets are 5'7" high, 5'1" wide, 2'2" deep with legs 1'5" high. Before each one place a wooden bench of the same height as the cabinet's legs; they are convenient to stand on when selecting type. Each case has 200 sliding drawers, and each drawer is divided into eight large and eight small compartments, each containing four large or four small type. Write the characters, with their classifiers and number of strokes, on labels on the front of each drawer.(Source: A Chinese Printing Manual, 1776. Translated by Richard C. Rudolph, 1954.)
The size measurements here are misleading. The translator says that the "inch" used here is the Chinese inch of the time, which is about 32.5 mm, not the 25.4 mm of the modern inch. He does not say what is meant by "foot"; I assume 12 inches. That means that the type cases are actually 7'2" high, 6'6" wide, 2'9" deep, (218 cm × 198 cm × 84 cm) with legs 1'10" high (55 cm), in modern units.
(Addendum 20060116: The quote doesn't say, but the illustration in Jin's book shows that the cabinets have 20 rows of 10 drawers each.)
One puzzle I have not resolved is that there do not appear to be enough type drawers. Jin writes that there are twelve cabinets with 200 drawers each; each drawer contains 16 compartments, and each compartment four type. This is enough space for 153,600 types (remember that you need multiples of the common characters), but Jin reports that 250,000 types were cut for his project. Still, it seems clear that the technique is feasible.
Another puzzle is that I still don't know what the "twelve divisions" of the Imperial K'ang Hsi Dictionary are. I examined a copy in the library and I didn't see any twelve divisions. Perhaps some reader can enlighten me.
As in Wang's project, one compositor would first go over the proof page, making a list of which types needed to be selected, and how many; new types were cut from wood as needed. Then compositors would visit the appropriate cases to select the types as necessary; another compositor would set the type, and then the page would be printed, and the type broken down. These activities were always going on in parallel, so that page n was being printed while page n+1 was being typeset, the types for page n+2 were being selected, and page n-1 was being broken down and its types returned to the cabinet.