[unicode] Re: x-bar character

[John Cowan]

Otto Stolz scripsit:

> Of course, if you allow for
> names comprising several characters, it would be better to spell out the
> multiplication operator; U+22C5,  U+2219, U+00B7, and 00D7 coming to mind.

Yes, of course.  But that wasn't at all the case I had in mind.  Letting x
and y be two random variables (misnomer if ever there was one, but hey),
then x-bar times y-bar is different from (x times y)-bar.  The former
wants a space between x-bar and y-bar, the latter wants a bar over both
x and y, and although COMBINING OVERLINE will serve to draw the latter,
and COMBINING MACRON the former, they are really both higher-level
constructs.

-- 
John Cowan   [EMAIL PROTECTED]
One art/there is/no less/no more/All things/to do/with sparks/galore
--Douglas Hofstadter

[unicode] Re: x-bar character

[J%ORG KNAPPEN]

John Cowan schrieb:

:Hmm.  If you multiply x-bar by y-bar, surely you want the bars to be
:separated, not run together into a single bar (which would be the mean
:of x times y), no?  In that case COMBINING MACRON would be better.
:Or should x-bar times y-bar be written with a THIN SPACE separating them?

With UNicode 3.2 you can place the character InvisibleTimes (Mathematica speak)
in between. But I agree, combining macron is better than combining bar in this
case. And the Invisible Times will be an optional embellishment for some 
time going -- tho it is really usefull in MathML and Computer Algebra.

--J"org Knapen

[unicode] Re: x-bar character

[John Cowan]

Roozbeh Pournader scripsit:

> I remember seeing an invisible times character somewhere, I think it was
> in 3.2 tables. Would you look?

Yes, at U+2062.  But I think that is truly invisible, zero-width, and is
used to render ab meaning a x b.

-- 
John Cowan   [EMAIL PROTECTED]
One art/there is/no less/no more/All things/to do/with sparks/galore
--Douglas Hofstadter

[unicode] Re: x-bar character

[Kenneth Whistler]

Roozbeh asked:

> I remember seeing an invisible times character somewhere, I think it was
> in 3.2 tables. Would you look?

U+2062 INVISIBLE TIMES

You can find such things at:

http://www.unicode.org/unicode/alloc/Pipeline.html

and

http://www.unicode.org/charts/draftunicode32/

or in the ISO/IEC 10646 amendment under ballot:

http://wwwold.dkuug.dk/JTC1/SC2/opn/dr.htm

and look at SC2 N3503.

--Ken

[unicode] Re: x-bar character

[Roozbeh Pournader]

On Thu, 22 Mar 2001, John Cowan wrote:

> Hmm.  If you multiply x-bar by y-bar, surely you want the bars to be
> separated, not run together into a single bar (which would be the mean
> of x times y), no?  In that case COMBINING MACRON would be better.
> Or should x-bar times y-bar be written with a THIN SPACE separating them?

I remember seeing an invisible times character somewhere, I think it was
in 3.2 tables. Would you look?

--roozbeh

[unicode] Re: x-bar character

[John Cowan]

Otto Stolz scripsit:

> This is a sequence of two Unicode characters, viz.
>   U+0078 LATIN SMALL LETTER X
>   U+0305 COMBINING OVERLINE
> Incidentally, the bar (rather than x-bar) signifies the mean; the bar
> could be applied to any name indicating the mean of all and any values
> having that name. In this respect, the combining overline mimicks the
> mathematical formalism better than any x-bar character would.

Hmm.  If you multiply x-bar by y-bar, surely you want the bars to be
separated, not run together into a single bar (which would be the mean
of x times y), no?  In that case COMBINING MACRON would be better.
Or should x-bar times y-bar be written with a THIN SPACE separating them?

-- 
John Cowan   [EMAIL PROTECTED]
One art/there is/no less/no more/All things/to do/with sparks/galore
--Douglas Hofstadter

[unicode] Re: x-bar character

[Otto Stolz]

Am 2001-03-21 um 18:56 UCT hat Eric Hausen geschrieben:
> Can anyone tell me the character code for the x-bar symbol (mathematical
> mean).

This is a sequence of two Unicode characters, viz.
  U+0078 LATIN SMALL LETTER X
  U+0305 COMBINING OVERLINE
Incidentally, the bar (rather than x-bar) signifies the mean; the bar
could be applied to any name indicating the mean of all and any values
having that name. In this respect, the combining overline mimicks the
mathematical formalism better than any x-bar character would.

Whether your software is capable of rendering the U+0078 U+0305 sequence
correctly, is another question. Ask your vendor for a decent Unicode (aka
ISO level 3) implementation.

Cf.
  
  

Best wishes,
  Otto Stolz