[NTG-context] Lua with xtable

[NTG-context] Lua with xtable

[Fabrice Couvreur]

Hi,
Can someone tell me where the error is in this code ?
Thanks for your help.
Fabrice


\starttext
\startluacode
context.startxtable({"align={middle,lohi},bodyfont=9pt"})
context.startxrow({"background=color,backgroundcolor=lightgray"})
context.startxcell({"background=color,backgroundcolor=white,width=0.6cm"})
context("")
context.stopxcell()
context.startxcell({"width=0.6cm"})
context("A")
context.stopxcell()
context.startxcell({"width=1.5cm"})
context("B")
context.stopxcell()
context.stopxrow()
context.startxrow()
context.startxcell({"width=0.6cm"})
context("1")
context.stopxcell()
context.startxcell()
context("\\im{n}")
context.stopxcell()
context.startxcell()
context("\\im{u_n}")
context.stopxcell()
context.stopxrow()
local p = {}
p[8] = 511
for i= 9, 17 do
    context.startxrow()
    context.startxcell() context(i-8) context.stopxcell()
    context.startxcell() context(i) context.stopxcell()
    context.startxcell() context("%0.3f", p[i]) context.stopxcell()
    context.stopxrow()
    p[i] =512*(1-1/(2^(i+1)))
end
context.stopxtable()
\stopluacode
\stoptext
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[NTG-context] Re: Lua with xtable

[Wolfgang Schuster]

Am 27.02.2026 um 16:15 schrieb Fabrice Couvreur:
> Hi,
> Can someone tell me where the error is in this code ?
> Thanks for your help.
> Fabrice
> 
>      context.startxcell() context("%0.3f", p[i]) context.stopxcell()
>      context.stopxrow()
>      p[i] =512*(1-1/(2^(i+1)))

You try to get the value of p[i] before it has been set.

Move p[i] = ... to the begin of the loop and it will work.

Wolfgang

___________________________________________________________________________________
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maillist : ntg-context@ntg.nl / https://mailman.ntg.nl/mailman3/lists/ntg-context.ntg.nl
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wiki     : https://wiki.contextgarden.net
___________________________________________________________________________________

[NTG-context] Re: Lua with xtable

[Fabrice Couvreur]

Hello Wolfgang,
Exactly, I should have paid more attention !

Thank you
Fabrice

Le ven. 27 févr. 2026 à 17:47, Wolfgang Schuster
<wolfgang.schuster.lists@gmail.com> a écrit :
>
> Am 27.02.2026 um 16:15 schrieb Fabrice Couvreur:
> > Hi,
> > Can someone tell me where the error is in this code ?
> > Thanks for your help.
> > Fabrice
> >
> >      context.startxcell() context("%0.3f", p[i]) context.stopxcell()
> >      context.stopxrow()
> >      p[i] =512*(1-1/(2^(i+1)))
>
> You try to get the value of p[i] before it has been set.
>
> Move p[i] = ... to the begin of the loop and it will work.
>
> Wolfgang
>
> ___________________________________________________________________________________
> If your question is of interest to others as well, please add an entry to the Wiki!
>
> maillist : ntg-context@ntg.nl / https://mailman.ntg.nl/mailman3/lists/ntg-context.ntg.nl
> webpage  : https://www.pragma-ade.nl / https://context.aanhet.net (mirror)
> archive  : https://github.com/contextgarden/context
> wiki     : https://wiki.contextgarden.net
> ___________________________________________________________________________________
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / https://mailman.ntg.nl/mailman3/lists/ntg-context.ntg.nl
webpage  : https://www.pragma-ade.nl / https://context.aanhet.net (mirror)
archive  : https://github.com/contextgarden/context
wiki     : https://wiki.contextgarden.net
___________________________________________________________________________________