Circumflex


The circumflex is a diacritic in the Latin and Greek scripts that is used in the written forms of many languages and in various romanization and transcription schemes. It received its English name from Latin circumflexus "bent around"a translation of the Greek περισπωμένη. The circumflex in the Latin script is chevron-shaped, while the Greek circumflex may be displayed either like a tilde or like an inverted breve.
In English, the circumflex, like other diacritics, is sometimes retained on loanwords that used it in the original language.
A similar typographical symbol, the caret is used in proof-reading and in programming.
In mathematics and statistics, the circumflex is used to denote a function and is called a hat operator.

Uses

Phonetic marker

Pitch

The circumflex has its origins in the polytonic orthography of Ancient Greek, where it marked long vowels that were pronounced with high and then falling pitch. In a similar vein, the circumflex is today used to mark tone contour in the International Phonetic Alphabet.
The shape of the circumflex was originally a combination of the acute and grave accents, as it marked a syllable contracted from two vowels: an acute-accented vowel and a non-accented vowel. Later a variant similar to the tilde was also used.
The term "circumflex" is also used to describe similar tonal accents that result from combining two vowels in related languages such as Sanskrit and Latin.
Since Modern Greek has a stress accent instead of a pitch accent, the circumflex has been replaced with an acute accent in the modern monotonic orthography.

Length

The circumflex accent marks a long vowel in the orthography or transliteration of several languages.
The circumflex accent marks the stressed vowel of a word in some languages:

English

In 18th century British English, before the cheap Penny Post and while paper was taxed, the combination ough was occasionally shortened to ô when the gh was not pronounced, to save space: thô for though, thorô for thorough, and brôt for brought.

French

In French, the circumflex generally marks the former presence of a consonant that was deleted and is no longer pronounced. For example:
Some homophones are distinguished by the circumflex. However, â, ê and ô distinguish different sounds in most varieties of French, for instance cote "level, mark, code number" and côte "rib, coast, hillside".
In handwritten French, for example in taking notes, an m with a circumflex is an informal abbreviation for même "same".
In February 2016, the Académie française decided to remove the circumflex from about 2000 words, a plan that had been outlined since 1990. However, usage of the circumflex would not be considered incorrect.

Italian

In Italian, î is occasionally used in the plural of nouns and adjectives ending with -io as a crasis mark. Other possible spellings are -ii and obsolete -j or -ij. For example, the plural of vario "various" can be spelt vari, varî, varii; the pronunciation will usually stay with only one. The plural forms of principe "prince" and of principio "principle, beginning" can be confusing. In pronunciation, they are distinguished by whether the stress is on the first or on the second syllable, but principi would be a correct spelling of both. When necessary to avoid ambiguity, it is advised to write the plural of principio as principî or as principii.

Norwegian

In Norwegian, the circumflex differentiates fôr "lining, fodder" from the preposition for. From a historical point of view, the circumflex also indicates that the word used to be spelled with the letter ð in Old Norsefor example, fôr is derived from fóðr, lêr 'leather' from leðr, and vêr "weather, ram" from veðr. After the ð disappeared, it was replaced by a d.

Mathematics

In mathematics, the circumflex is used to modify variable names; it is usually read "hat", e.g., î is "i hat". The Fourier transform of a function ƒ is often denoted by.
In the notation of sets, a hat above an element signifies that the element was removed from the set, such as in, the set containing all elements except.
In geometry, a hat is sometimes used for an angle. For instance, the angles or.
In vector notation, a hat above a letter indicates a unit vector. For instance,,, or stands for a unit vector in the direction of the x-axis of a Cartesian coordinate system.
In statistics, the hat is used to denote an estimator or an estimated value, as opposed to its theoretical counterpart. For example, in errors and residuals, the hat in indicates an observable estimate of an unobservable quantity called . It is read x-hat or x-roof, where x represents the character under the hat.

Music

In music theory and musicology, a circumflex above a numeral is used to make reference to a particular scale degree.
In music notation, a chevron-shaped symbol placed above a note indicates marcato, a special form of emphasis or accent. In music for string instruments, a narrow inverted chevron indicates that a note should be performed up-bow.

Circumflex in digital character sets

The precomposed characters Â/â, Ê/ê, Î/î, Ô/ô, and Û/û are included in the ISO-8859-1 character set, and dozens more are available in Unicode. In addition, Unicode has and which in principle allow adding the diacritic to any base letter.

Freestanding circumflex

For historical reasons, there is a similar but larger character, , which is also included in ASCII but often called a caret instead. It is, however, unsuitable for use as a diacritic on modern computer systems, as it is a spacing character. Another spacing circumflex character in Unicode is the smaller, mainly used in phonetic notationsor as a sample of the diacritic in isolation.

Typing the circumflex accent

In countries where the local language routinely include letters with a circumflex, local keyboards are typically engraved with those symbols. For users with American or British QWERTY keyboards, the characters â, ĉ, ê, ĝ, ĥ, î, ĵ, ô, ŝ, û, ẃ, ý may be obtained after installing the International or extended keyboard layout setting. Then, by using , release, then etc.. Alternatively for systems with a 'compose' function, use, etc.