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The modern numerical digit [[0 (number)|0]] is usually written as a circle, an ellipse, or a rounded rectangle. | |||
==Glyphs== | |||
[[File:Text figures 036.svg|71px|left]] | |||
In most modern [[typeface]]s, the height of the 0 character is the same as the other digits. However, in typefaces with [[text figures]], the character is often shorter ([[x-height]]). | |||
[[File:Zero o comparison.svg|A comparison of the letter O and the number 0|right]] | |||
Traditionally, many print typefaces made the capital letter [[O]] more rounded than the narrower, elliptical digit 0.<ref name="bemer" /> [[Typewriter]]s originally made no distinction in shape between O and 0; some models did not even have a separate key for the digit 0. The distinction came into prominence on modern character [[Visual display unit|displays]].<ref name="bemer">R. W. Bemer. "Towards standards for handwritten zero and oh: much ado about nothing (and a letter), or a partial dossier on distinguishing between handwritten zero and oh". ''Communications of the ACM'', Volume 10, Issue 8 (August 1967), pp. 513–518.</ref> | |||
The digit 0 with a dot in the centre seems to have originated as an option on [[IBM 3270]] displays. Its appearance has continued with the [[Microsoft Windows]] typeface [[Andalé Mono]]. One variation used a short vertical bar instead of the dot. This could be confused with the [[Greek alphabet|Greek letter]] [[Theta]] on a badly focused display, but in practice there was no confusion because theta was not (then) a displayable character and very little used anyway. | |||
An alternative, the [[slashed zero]] (looking similar to the letter O except for the slash), was primarily used in hand-written coding sheets before transcription to punched cards or tape, and is also used in old-style [[ASCII]] graphic sets descended from the default typewheel on the [[Teletype Model 33]] ASR. This form is similar to the symbol <math>\emptyset</math>, or "∅" ([[Unicode]] character U+2205), representing the [[empty set]], as well as to the letter [[Ø]] used in several [[North Germanic languages|Scandinavian languages]]. Some [[Burroughs Corporation|Burroughs]]/[[Unisys]] equipment displays a digit 0 with a ''reversed'' slash. | |||
The opposing convention that has the letter O ''with'' a slash and the digit 0 ''without'' was advocated by SHARE, a prominent [[IBM]] user group,<ref name="bemer"/> and recommended by IBM for writing [[Fortran|FORTRAN]] programs,<ref name="einarsson">Bo Einarsson and Yurij Shokin. ''Fortran 90 for the Fortran 77 Programmer''. [http://www.nsc.liu.se/~boein/f77to90/a7.html Appendix 7: "The historical development of Fortran"]</ref> and by a few other early mainframe makers; this is even more problematic for Scandinavians because it means two of their letters collide. Others advocated the opposite convention,<ref name="bemer" /> including IBM for writing [[Algol]] programs.<ref name="einarsson" /> Another convention used on some early [[line printer]]s left digit 0 unornamented but added a tail or hook to the capital O so that it resembled an inverted [[Q]] or cursive capital letter-O (<math>\mathcal O</math>).<ref name="bemer" /> | |||
Some fonts designed for use with computers made one of the capital-O–digit-0 pair more rounded and the other more angular (closer to a rectangle). The [[Texas Instruments TI-99/4A]] computer featured a more angular capital O and a more rounded digit 0, whereas others made the choice the other way around. | |||
[[File:Deutsches Kfz-Kennzeichen für Behördenfahrzeuge (Nummernbereich 3).jpg|thumb|German license plate with slit zeros]] | |||
The typeface used on most European [[vehicle registration plate]]s distinguishes the two symbols partially in this manner (having a more rectangular or wider shape for the capital O than the digit 0), but in several countries a further distinction is made by slitting open the digit 0 on the upper right side (as in [[Vehicle registration plates of Germany|German plates]] using the ''[[FE-Schrift|fälschungserschwerende Schrift]]'', "harder-to-falsify script"). | |||
Sometimes the digit 0 is used either exclusively, or not at all, to avoid confusion altogether. For example, [http://southwest.com/content/travel_center/retrieveCheckinDoc.html confirmation numbers] used by [[Southwest Airlines]] use only the capital letters O and I instead of the digits 0 and 1, while [[Canadian postal code]]s use only the digits 1 and 0 and never the capital letters O and I, although letters and numbers always alternate. | |||
==Other== | |||
{| align="right" | |||
| [[File:7-segment cdeg.svg|80px|Unusual smaller appearance of zero on seven-segment displays]] | |||
| [[File:7-segment abcdef.svg|80px|Usual appearance of zero on seven-segment displays]] | |||
|} | |||
On the [[seven-segment display]]s of calculators, watches, and household appliances, 0 is usually written with six line segments, though on some historical calculator models it was written with four line segments. | |||
In [[Braille]], the numeral 0 has the same dot configuration as the letter [[J]]. | |||
[[File:ICS Zero.svg|thumb|[[International maritime signal flags|International maritime signal flag]] for 0]] | |||
==References== | |||
{{reflist}} | |||
[[Category:Zero]] | |||
[[Category:Symbols]] | |||
Revision as of 06:02, 19 July 2013
The modern numerical digit 0 is usually written as a circle, an ellipse, or a rounded rectangle.
Glyphs
In most modern typefaces, the height of the 0 character is the same as the other digits. However, in typefaces with text figures, the character is often shorter (x-height).
Traditionally, many print typefaces made the capital letter O more rounded than the narrower, elliptical digit 0.[1] Typewriters originally made no distinction in shape between O and 0; some models did not even have a separate key for the digit 0. The distinction came into prominence on modern character displays.[1]
The digit 0 with a dot in the centre seems to have originated as an option on IBM 3270 displays. Its appearance has continued with the Microsoft Windows typeface Andalé Mono. One variation used a short vertical bar instead of the dot. This could be confused with the Greek letter Theta on a badly focused display, but in practice there was no confusion because theta was not (then) a displayable character and very little used anyway.
An alternative, the slashed zero (looking similar to the letter O except for the slash), was primarily used in hand-written coding sheets before transcription to punched cards or tape, and is also used in old-style ASCII graphic sets descended from the default typewheel on the Teletype Model 33 ASR. This form is similar to the symbol , or "∅" (Unicode character U+2205), representing the empty set, as well as to the letter Ø used in several Scandinavian languages. Some Burroughs/Unisys equipment displays a digit 0 with a reversed slash.
The opposing convention that has the letter O with a slash and the digit 0 without was advocated by SHARE, a prominent IBM user group,[1] and recommended by IBM for writing FORTRAN programs,[2] and by a few other early mainframe makers; this is even more problematic for Scandinavians because it means two of their letters collide. Others advocated the opposite convention,[1] including IBM for writing Algol programs.[2] Another convention used on some early line printers left digit 0 unornamented but added a tail or hook to the capital O so that it resembled an inverted Q or cursive capital letter-O ().[1]
Some fonts designed for use with computers made one of the capital-O–digit-0 pair more rounded and the other more angular (closer to a rectangle). The Texas Instruments TI-99/4A computer featured a more angular capital O and a more rounded digit 0, whereas others made the choice the other way around.
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The typeface used on most European vehicle registration plates distinguishes the two symbols partially in this manner (having a more rectangular or wider shape for the capital O than the digit 0), but in several countries a further distinction is made by slitting open the digit 0 on the upper right side (as in German plates using the fälschungserschwerende Schrift, "harder-to-falsify script").
Sometimes the digit 0 is used either exclusively, or not at all, to avoid confusion altogether. For example, confirmation numbers used by Southwest Airlines use only the capital letters O and I instead of the digits 0 and 1, while Canadian postal codes use only the digits 1 and 0 and never the capital letters O and I, although letters and numbers always alternate.
Other
|
|
On the seven-segment displays of calculators, watches, and household appliances, 0 is usually written with six line segments, though on some historical calculator models it was written with four line segments.
In Braille, the numeral 0 has the same dot configuration as the letter J.
References
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- ↑ 1.0 1.1 1.2 1.3 1.4 R. W. Bemer. "Towards standards for handwritten zero and oh: much ado about nothing (and a letter), or a partial dossier on distinguishing between handwritten zero and oh". Communications of the ACM, Volume 10, Issue 8 (August 1967), pp. 513–518.
- ↑ 2.0 2.1 Bo Einarsson and Yurij Shokin. Fortran 90 for the Fortran 77 Programmer. Appendix 7: "The historical development of Fortran"