Re: \unit problem with powers of ten.

[Romain Diss <romain.diss@yahoo.fr>]

Hi all,

Le mardi 20 novembre 2012, Romain Diss a écrit :
> Le lundi 19 novembre 2012, Romain Diss a écrit :
> > I got some problems to express powers of ten in the \unit command. See
> > the strange behaviour with these two minimal examples.
> > 
> > \starttext
> > \unit{10^2 meter}\\
> > \unit{10^{-12} second}
> > \stoptext
> > Is this a bug or are these expressions not supported?
> 
> I'm not an expert neither in TeX nor Lua, but I quickly glance at the
> source code (phys-dim.*) and here is what I understand:
> — the brackets { } are not recognized (a comment in the lua code mentioned
> it), so \unit{10^{-12} second} should be \unit{10^-12 second};
> — the hat sign '^' is recognized as 'e' so it means "… times ten to the
> power…" instead of "to the power…" as one should expect.
> 
> So I come back to my problem. I want to write 10⁻¹² s (ten to the negative
> twelfth power second). Actually, I'm typing \math{10^{-12} \unit{second}}
> but I'd prefer to type \unit{10^-12 second} (for coherence). Is it
> possible to modify phys-dim.lua in that way or is this to much work (I
> have no idea if this is a matter of changing one line or a hundred lines
> in phys-dim.lua. Maybe also this is a too specific request, I don't know…

Nobody seems very enthusiastic concerning this thread so I tried to go further 
in the comprehension of the phys-dim.lua code. I now have found an approximate 
solution to my problem :
\unit{$10^{-12}$ second}
give the right result. It is not very satisfactory because I'm now used to use 
\m{} instead of $ $. In the phys-dim.lua code, the line 64 shows that \m{} can 
be used inside \unit{} but this doesn't work for:
\unit{\m{10^{-12}} second}
because the pattern doesn't handle nested curly braces.

Is there any Lua expert to find a pattern to handle exponents?

Thank you.

-- 
Romain Diss
<romain.diss@yahoo.fr>
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