Digamma
Will Robertson
Unicode has digamma in amongst the text Greek letters (plus a bold
upright version in the math plane that seems to be supported by
absolutely zero fonts including STIX). Hence, it is upright. But
amssymb defines \digramma as an italic letter. Is this anything I need
to worry about? (I.e., can I assume for once that amsmath is wrong and
mathematicians everywhere prefer it upright?)
Judging by symbols-a4.pdf, LaTeX has never known anything about the
capital Digamma, so I'm not sure what to make of that one.
--
Will
Andrew Moschou
Unicode has digamma in amongst the text Greek letters (plus a bold
upright version in the math plane that seems to be supported by
absolutely zero fonts including STIX).
GNU FreeSerif includes them.
Hence, it is upright. But
amssymb defines \digramma as an italic letter.
Does it?
from amsfonts:
The glyph itself is slanted, but so are all lowercase Greek in Computer Modern, so I wouldn't interpret that too much.
Is this anything I need
to worry about? (I.e., can I assume for once that amsmath is wrong and
mathematicians everywhere prefer it upright?)
I haven't seen enough mathematics to have ever seen the digamma letter used in an equation. But from what I gather, most people prefer to use \psi (!) for the digamma function. I'm trying to dig up a mathematical font that includes digamma and the offerings from Adobe, Linotype and Monotype don't seem to include them. However, I see that the free URW fonts (whose greek characters seem to be taken from Monotype Math & Technical) include a digamma (I think) in PUA U+EFD5 which is slanted. For what it's worth I'd prefer to see all Unicode digammas upright (but if I were to write a work that uses digamma, I might use it slanted to match the other Greek letters).
Andrew
Will Robertson
> The glyph itself is slanted, but so are all lowercase Greek in
> Computer Modern, so I wouldn't interpret that too much.
Good point.
Thanks for the reference to FreeSerif.
> I haven't seen enough mathematics to have ever seen the digamma
> letter used in an equation. But from what I gather, most people
> prefer to use \psi (!) for the digamma function. I'm trying to dig
> up a mathematical font that includes digamma and the offerings from
> Adobe, Linotype and Monotype don't seem to include them. However, I
> see that the free URW fonts (whose greek characters seem to be taken
> from Monotype Math & Technical) include a digamma (I think) in PUA U
> +EFD5 which is slanted. For what it's worth I'd prefer to see all
> Unicode digammas upright (but if I were to write a work that uses
> digamma, I might use it slanted to match the other Greek letters).
I suppose in practise there will always be these edge cases where
unicode doesn't quite suffice, and one will, say, want to insert an
italic digamma from an italic font. (Or a sans serif Greek letter!)
The link you sent me on Greek typography "From Unicode to Typography,
a Case Study: the Greek Script" by Yannis Haralambous claims that
digamma is a very rare mathematical symbol. My personal opinion is
that if digamma is popular enough to deserve a bold variation then an
italic one makes sense for the same reasons that the italic math plane
exists (especially considering even "useless" letters like Alpha and
omicron are encoded). But it's not the end of the world or anything --
I just thought it was worth mentioning at this stage.
--
Will
Apostolos Syropoulos
The link you sent me on Greek typography "From Unicode to Typography,
a Case Study: the Greek Script" by Yannis Haralambous claims that
digamma is a very rare mathematical symbol. My personal opinion is
I am no mathematician by training but I use mathematics extensively. However, I haven't seen
a usage example of digamma in any Greek or English language book. Digamma is an
archaic letter that is not used even by philologists.
A.S.
--
Apostolos Syropoulos
GR-671 00 Xanthi, GREECE
Ross Moore
On 03/10/2009, at 3:15 AM, Apostolos Syropoulos wrote:
>
>
> 2009/10/2 Will Robertson <wsp...@gmail.com>
>
>
> The link you sent me on Greek typography "From Unicode to Typography,
> a Case Study: the Greek Script" by Yannis Haralambous claims that
> digamma is a very rare mathematical symbol. My personal opinion is
>
>
> I am no mathematician by training but I use mathematics
> extensively. However, I haven't seen
> a usage example of digamma in any Greek or English language book.
> Digamma is an
> archaic letter that is not used even by philologists.
This link seems to be pretty good about it:
http://www.bookrags.com/wiki/Digamma_function
Other places, such as
http://mathworld.wolfram.com/DigammaFunction.html
just use an ordinary F --- which, though pragmatic,
is not really suitable for a specially-named function.
Note that, as the Wolfram link explains, the \digamma
and \Psi functions are actually different --- though very
closely connected, so each may be called the "digamma function".
The idea of using ancient characters, that appear in Unicode fonts
but are not used anymore elsewhere, is actually rather appealing.
This avoids mis-interpretation and the problems of which encoding
point should be used. (cf. our earlier discussions concerning
\partial and other math-Greek letters).
>
> A.S.
>
> --
> Apostolos Syropoulos
> GR-671 00 Xanthi, GREECE
Cheers,
Ross
------------------------------------------------------------------------
Ross Moore ro...@maths.mq.edu.au
Mathematics Department office: E7A-419
Macquarie University tel: +61 (0)2 9850 8955
Sydney, Australia 2109 fax: +61 (0)2 9850 8114
------------------------------------------------------------------------
Will Robertson
> I am no mathematician by training but I use mathematics extensively.
> However, I haven't seen
> a usage example of digamma in any Greek or English language book.
> Digamma is an
> archaic letter that is not used even by philologists.
Considering its rarity in my Greek text and mathematics, I suppose
it's fine to have only a single codepoint in unicode. If necessary,
font designers can use an OpenType feature to switch between a "math
style" and "letter style".
The range of styles is quite diverse: (the second-to-bottom line is
the baseline; third-to-bottom is the x-height)
Cambria:
Apostolos Syropoulos
>
>
> This link seems to be pretty good about it:
>
> http://www.bookrags.com/wiki/Digamma_function
>
> Other places, such as
>
> http://mathworld.wolfram.com/DigammaFunction.html
>
OK but there is also the so-called polygamma function
http://mathworld.wolfram.com/PolygammaFunction.html
and obviously there is no polygamma symbol:-)
So I believe that digamma does not refer to the ancient
letter but to something that is two times the Gamma function
or something like this. But of course this is based my intuition
and not to knowledge of things.
> The idea of using ancient characters, that appear in Unicode fonts
> but are not used anymore elsewhere, is actually rather appealing.
I agree.
firmicus04
On Oct 2, 7:15 pm, Apostolos Syropoulos <ijdt.edi...@gmail.com> wrote:
> 2009/10/2 Will Robertson <wsp...@gmail.com>
>
>
>
> > The link you sent me on Greek typography "From Unicode to Typography,
> > a Case Study: the Greek Script" by Yannis Haralambous claims that
> > digamma is a very rare mathematical symbol. My personal opinion is
>
> I am no mathematician by training but I use mathematics extensively.
> However, I haven't seen
> a usage example of digamma in any Greek or English language book. Digamma is
> an
> archaic letter that is not used even by philologists.
>
the alphabet already in classical times but they were retained to
denote numeral values. They were still used for that purpose in
Byzantine manuscripts. Thus contemporary scholars who edit Greek
astronomical texts, for instance, do frequently need these letters. Of
course this is outside the scope of this mailing list.
BTW, Apostolos is right that the digamma letter has nothing to do with
the Digamma function, of which I vaguely remember from my old days as
a student of mathematical physics :).
François Charette