Point (upper sign)

Diacritical marks
designation	character
Acute, simple	◌́
Acute, double	◌̋
Breve, about it	◌̆
Breve, including	◌̮
Cedilla, including	◌̧
Cedilla, about it	◌̒
Gravis, simple	◌̀
Gravis, double	◌̏
hook	◌̉
Hatschek	◌̌
horn	◌̛
Comma below	◌̦
Coronis	◌̓
Kroužek, about it	◌̊
Kroužek, including	◌̥
Macron, about it	◌̄
Macron, underneath	◌̱
Ogonek	◌̨
Period about that	◌̇
Point below	◌̣
Dash	◌̶
diacritical slash	◌̷
Alcohol asper	◌̔
Spiritus lenis	◌̕
Tilde, about it	◌̃
Tilde, underneath	◌̰
Trema, about it	◌̈
Trema, including	◌̤
circumflex	◌̂

Ȧȧ Ḃḃ Ċċ Ḋḋ
Ėė Ḟḟ Ġġ Ḣḣ
İ Ṁṁ Ṅṅ Ȯȯ
Ṗṗ Ṙṙ Ṡṡ Ṫṫ
Ẇẇ Ẋẋ Ẏẏ Żż

The over dot is a diacritical mark that is used in many languages and used for other purposes.

use

As a diacritical mark

The over point as a diacritical mark (phonetic variant) occurs relatively rarely in European languages (except for i and j, where it is usually not regarded as such). Examples are ċ / Ċ and ġ / Ġ in Maltese and Irish (old spelling), ė / Ė in Lithuanian , i / İ in Turkish and ż / Ż in Polish and Maltese.

As any other phonetic sign

In addition, the over dot is used for the notation of the fifth of the tones of standard Chinese , the neutral tone ( Chinese 輕聲 / 轻声 , Pinyin qīng shēng - "light tone").

As a scientific symbol

In the notation of physics and technology , the superpoint is usually used to represent the derivative of a quantity specifically and exclusively according to time , Newton's notation of the derivative :

For example, the can speed as the derivative of the path with respect to time for short as shown are

{\ displaystyle v}

{\ displaystyle x}

{\ displaystyle t}

{\ displaystyle {\ dot {x}}}

{\ displaystyle v = {\ frac {dx} {dt}} = {\ dot {x}}}

In some cases (especially when using polar coordinates ), however, a derivative according to an angle is also expressed using this notation:

{\ displaystyle {\ frac {d \ rho \,} {d \ varphi \,}} = {\ dot {\ rho \,}}}

The second derivative after time is then noted with a colon ( trema ) . This use goes back to Isaac Newton's differential calculus , while in mathematics Leibniz's notation with the apostrophe (today as a typographically independent character, the prime ) is used throughout . ${\ displaystyle {\ ddot {x}}}$ ${\ displaystyle x '}$

In mathematics , a point above one or more digits of a number is used to display periodically repeating decimal places . Examples:

A third = 1/3 = 0.33 ... = 0.3 with a point above the three.

1/99 = 0.0101 ... = 0.01 with points above the 2 digits after the decimal point.

1/999 = 0.001001 ... = 0.001 with one point each over the 1st AND 3rd or 1st TO 3rd decimal place. (There are two conventions here, none of which can be misunderstood. An alternative representation uses underline or underline (e).)

Presentation on the computer

Character sets

˙

The dot accent does not appear in the ASCII character set . In the character sets of the ISO-8859 family , selected characters appear with the dot accent.

In addition to the examples given above, Unicode contains additional compound Latin letters with a point and can represent any characters with a point by adding a combining point U + 0307 COMBINING DOT ABOVE ( Unicode block combining diacritical marks 0300-036F); the single glyph of the diacritic is located on code point U + 02D9 DOT ABOVE in the Unicode block Spacing Modifier Letters (02B0-02FF).

annotation

↑ In Unicode jargon, the term spacing means that the glyph has its own place (is a separate character), combining that - assuming the UC specifications are correctly represented by the software - with the preceding or following character, depending on the type , merged into a glyph.

TeX and LaTeX

TeX and LaTeX can represent any characters with a point. There are two different commands for this:

In text mode for text typesetting, \.ca ċ is created.
In the math mode for the formula set, generates \dot athe formula and the formula . ${\ displaystyle {\ dot {a}}}$ \ddot a ${\ displaystyle {\ ddot {a}}}$

Web links

Letters with overdot and their Unicode masking

[1] In Unicode jargon, the term spacing means that the glyph has its own place (is a separate character), combining that - assuming the UC specifications are correctly represented by the software - with the preceding or following character, depending on the type , merged into a glyph.