Cangjie method

*Note: Some variants use Z as a collision key instead of X, in those systems Z has the name 重 and X has the name 難; but the use of Z as a collision key is neither in the original Cangjie nor used in the current mainstream implementations; in some other variants, Z may have the name 造 (user-defined) or some other names

</table> The auxiliary shapes of each Cangjie radical have changed slightly between different versions of the Cangjie method; this is one reason why different versions of the Cangjie method are not completely compatible.

Keyboard layout

Image:Keyboard layout Cangjie.png

The basic rules

The typist must be familiar with several decomposition rules 拆字規則 that defines how to analyse a character to arrive at a Cangjie code.

• Direction of decomposition: left to right, top to bottom, and outside to inside
• Geometrically connected forms: take 4 Cangjie codes, namely the first, second, third, and last codes
• Geometrically unconnected forms: identify the first geometrically connected subform according to the direction of decomposition rule, then take the first and last codes of the subform; next consider the rest of the original form, and take the first, second, and last code of this subform. (If the second subform is itself geometrically unconnected, the second code taken is the last code in the first geometrically-connected subform of this second subform.)

The rules are subject to various principles:

• Conciseness (精簡) — if two decompositions are possible, the shorter decomposition is correct
• Completeness (原整) — if two decompositions of the same length are possible, the one that identifies a more complex form first is the correct decomposition
• Reflection of the form of the radical (字型特徵) — the decomposition should reflect the shape of the radical, meaning (a) the same code used twice or more is to be avoided if possible, and (b) the shape of the character should not be "cut" at a corner in the form
• Omission of codes (省略)
  • Partial omission (部分省略) — when the number of codes in a complete decomposition would exceed the permitted number of codes, the extra codes are ignored
  • Omission in enclosed forms (包含省略) — when part of the character need to be decomposed and the form is an enclosed form, only the shape of the enclosure is decomposed; the enclosed forms are omitted

The short list of exceptions

Some forms are always decomposed in the same way, whether the rules say they should be decomposed this way or not. Fortunately, the number of exceptions are few:

Examples

• 車 (chē, vehicle)
  • This character is geometrically connected, consisting of one part with a vertical structure, so we take the first, second, and last Cangjie codes from top to bottom.
  • The Cangjie code is thus 十 田 十 (JWJ), corresponding to the basic shapes of the codes in this example.
• 謝 (xiè; to thank, to wither)
  • This character geometrically consists of unconnected parts arranged horizontally. For the initial decomposition, we treat it as two parts, 言 and 射.
  • The first part, 言, is geometrically unconnected from top to bottom; we take the first (, auxiliary shape of 卜 Y) and last parts (口, basic shape of 口 R) and arrive at 卜 口 (YR).
  • The second part is again geometrically unconnected, arranged horizontally. The two parts are 身 and 寸.
    • For the first part of this second part, 身, we take the first and last codes. Both are slants and therefore H; the first and last codes are thus 竹 竹 (HH).
    • For the second part of the original second part, 寸, we take only the last part. Because this is geometrically unconnected consisting of two parts, the first part is the outer form while the second part is the dot in the middle. The dot is I, and therefore the last code is 戈 (I).
  • The Cangjie code is thus 卜 口 (YR) 竹 竹 (HH) 戈 (I), or 卜 口 竹 竹 戈 (YRHHI).
• 谢 (simplified version of 謝)
  • This example is identical to the above, except that the first part is 讠; the first and last codes are 戈 (I) and 女 (V)
  • Repeating the same steps as the above example, we get 戈 女 (IV) 竹 竹 (HH) 戈 (I), or 戈 女 竹 竹 戈 (IVHHI).

Early Cangjie system

In the beginning, the Cangjie input method was not a way to produce a character in any character set. It was, instead, an integrated system consisting of the Cangjie input rules and a Cangjie controller board. The controller board contains character generator firmware, which dynamically generates Chinese characters from Cangjie codes when characters are output, using the hi-res graphics mode of an Apple II computer. In the preface of the Cangjie user's manual, Mr. Chu wrote in 1982

[Translation]
In terms of output: The output and input, in fact, [form] an integrated whole; there is no reason that [they be] dogmatically separated into two different facilities.… This is in fact necessary.…

In this early system, when the user types "yk " (for example) to get the Chinese character 文, the Cangjie codes does not get converted to any character encoding; the actual string "yk " is stored. In a very real sense, the Cangjie code of each character (string of 1 to 5 lowercase letters plus a space) was the encoding of that particular character.

A particular interesting "feature" of this early system is that if you send random lowercase words to the character generator, it will attempt to construct Chinese characters according to the Cangjie decomposition rules, sometimes causing strange, unknown characters to appear. This unusual feature, "automatic generation of characters", is actually described in the manual and is responsible for producing more than 10,000 of the about 15,000 characters that the system can handle. The name Cangjie, evocative of creation of new characters, was actually very apt for this early version of Cangjie.

The presence of the integrated character generator also explains the historical necessity of existence of the "X" key as used for disambiguation of decomposition collisions: because characters are "chosen" when the codes are output, every character that can be displayed must in fact have one and only one Cangjie decomposition. It would not make sense—nor would it be practical—for the system to provide a choice of candidate characters when some random text file is displayed; the user would not know which of the candidates are correct.

Issues

Cangjie was designed to be an easy-to-use system to help promote the use of Chinese computing; nevertheless, many users find Cangjie to be a difficult method. Many of the perceived difficulties arise from poor instruction

Perceived difficulties

• In order to input using Cangjie, one must know not only the names of the radicals, but also all their auxiliary shapes (which might not appear to make sense, though Mr. Chu had intended all the auxiliary shapes to be related to the basic shapes and "easy to remember"); it is common to find tables of the Cangjie radicals with their auxiliary shapes taped onto the monitors of casual computer users.
• One must also be familiar with the decomposition rules; unfortunately, a lot of casual computer users are not even aware of the existence of decomposition rules but rather type by guessing. This makes Cangjie a very difficult method.

Enough practice, however, can overcome the above problems. A typist with sufficient practice in Cangjie touch types, much like a typist that works on the English language; it is entirely possible for a touch typist to type at 25 words (Chinese characters) per minute or better in Cangjie, yet have difficulty remembering the list of auxiliary shapes or even the decomposition rules. Experienced Cangjie typists can reportedly attain a typing speed between 60 wpm and over 200 wpm.

Cangjie, however, also have some "real" problems:

Actual difficulties

• Cangjie is not error forgiving (不容錯): The decomposition of a character depends on a predefined set of "standard shapes" (標準字形); however, because Cangjie is used in many different countries, the standard shape of a certain character in Cangjie is not always the standard shape of the same character the user has learnt. Learning Cangjie would then entail not only learning Cangjie itself, but also the standard shape of some characters. The difference between 溫 and 温, or 黑 and 黒, for example, illustrates the frustration learners of Cangjie might have to go through. The Cangjie IME is also not expected to handle mistakes in decomposition other than tell the user (usually by beeping) that there is a mistake.
• Punctuation marks are not geometrically decomposed, but rather given random-looking codes that begin with ZX followed by a string of three letters related to the ordering of the characters in the Big5 code. Typing punctuation marks in Cangjie thus becomes a frustrating exercise in either memorization or pick-and-peck.
• The user cannot type a character which he or she has forgotten how to write. This, of course, is not a real problem with Cangjie but a problem with all non-phonetic input methods. (This is not to say that phonetic input methods are superior; in fact they suffer from the opposite problem, namely that the user cannot type a character which he or she does not know how to pronounce.)

In some situations it cannot be used at all. Cangjie uses all 26 keys in an English (United States) keyboard, it cannot be used to input Chinese on cell phones. For cell phones, the Q9 method is the current norm because it is designed specifically for use on numeric keypads.

Versions of Cangjie

The Cangjie input method is commonly said to have gone through 5 generations (commonly referred to as “versions” in English), each of which slightly incompatible with the other. Currently, version 3 (第三代倉頡) is the most common, being the version of Cangjie supported natively by Microsoft Windows. Version 5 (第五代倉頡), supported by the Free Cangjie IME and previously the only Cangjie supported by SCIM, is a significant minority.

The early Cangjie system supported by the Zero One card on the Apple II was Version 2; Version 1 had never been released.

The Cangjie input method supported on the Mac OS is somewhat like Version 3 and somewhat like Version 5.

Besides the original Cangjie input method, Version 5 was also created directly by Mr Chu, the inventor. Originally slated for release as Version 6, Mr Chu had hoped that the release of Version 5 would bring an end to the “more than ten versions of Cangjie input method” (slightly incompatible versions created by different vendors).

Variants of Cangjie

Most modern implementations of Cangjie IME's provide various convenience features:

• Some IME's lists all characters beginning with the code you have typed; for example, if you type A, the system gives you all characters whose Cangjie code begins with A so that you can select the correct character if it is on the screen; if you type another A, the list is shortened to give all characters whose code begins with AA. Examples of such implementations include the IME in Mac OS X, and SCIM.
• Some IME's provide one or more wildcard keys, usually but not always * and/or ?, that allows the user to omit part(s) of the Cangjie code; the system will display a list of matching characters for the user to choose. Examples of such implementations include xcin, SCIM, and the IME in the Founder (University of Peking) typesetting systems.
• Some IME's provide an "abbreviation" feature, where impossible Cangjie codes are interpreted as abbrevations of the Cangjie codes of more than one character, allowing more characters to be input with less keys. An example of such an implementation is SCIM.
• Some IME's provide an "association" (聯想 lianxiang) feature, where the system anticipates what you are going to type next, and provides you with a list of characters or even phrases associated with what the user has typed. An example of such an implementation is the Microsoft Cangjie IME.
• Some IME's present the list of candidate characters differently depending on the frequency of use of the characters (how many of the same character has been typed by the user). An example of such an implementation is the Cangjie IME in NJStar.

Besides the wildcard key, many of the above features are very convenient for casual users but unsuitable for touch typists because they make the Cangjie IME unpredictable.

There are also various attempts to "simplify" Cangjie one way or another:

• Simplified Cangjie has the same radicals, auxiliary shapes, decomposition rules, and short list of exceptions as Cangjie, but only the first and last codes are used if more than 2 codes are required in Cangjie

See also

• Chinese input methods for computers
• keyboard layout

References

• Taipei: Chwa! Taiwan Inc. (全華科技圖書公司). 倉頡中文資訊碼 : 倉頡字母、部首、注音三用檢字對照 [The Cangjie Chinese information code : with indexes keyed by Cangjie radicals, Kangxi radicals, and zhuyin]. Publication number 023479. — This is the user manual of an early Cangjie system with a Cangjie controller card.
  • The second-last paragraph on the first page in the section entitled "The Cangjie radical-based Chinese input method" (倉頡字母中文輸入法) states that

    [Translation]
    This is no problem; there are also auxiliary forms to complement the deficiencies of the radicals. The auxiliary forms are variations of the shape of the radicals, [and therefore] easy to remember.

  • The last paragraph on the fifth page in the same section states

    [Translation]
    The dictionary appended in the back [of this book] is based on the 4800 standard, commonly used characters proclaimed by the Ministry of Education. Adding to this the characters that are automatically generated, the number of characters is about 15,000 (using the Kangxi dictionary as a basis).

• Part of the information from this article comes from the equivalent Chinese-language wikipedia article
• The decomposition rules come from the "Friend of Cangjie — Malaysia" web site at http://www.chinesecj.com/ The site also gives the typing speed of experienced typists.
• It might be difficult to find specific references to the "not error forgiving" property of Cangjie. The table at http://www.array.com.tw/keytool/compete.htm is one external reference that states this fact.
• http://input.foruto.com/introduce/introduce_article021.htm has a brief history of the Cangjie input method as seen by that article‘s author. Versions 1 and 2 are clearly identified in the article.
• http://www.cbflabs.com/book/essay/agdi0.htm contans a number of articles written by Mr Chu Bong-Foo, with references not only to the Cangjie input method, but also Chinese language computing in general. Versions 5 and 6 (now referred to as 5) of the Cangjie input method are clearly identified.

External links

• The Chinese University of Hong Kong Research Centre for Humanities Computing: Chinese Character Database: With Word-formations Phonologically Disambiguated According to the Cantonese Dialect: A Chinese character database covering the entire set of Big-5 chinese characters (5401 Level 1 and 7652 Level 2 Hanzi) as well as 7 additional ETen Hanzi. Cangjie input codes are shown for each character in the database. Note: The Hong Kong Supplementary Character Set (HKSCS - 2001) is not included in this database.
• Sino Input Method Online (input Chinese using Cangjie method without installation)ja:倉頡輸入法

zh:倉頡輸入法