Re: [NTG-context] Fwd: Continued fractions in ConTeXt

29 Jun 2020


      On 6/28/2020 6:06 PM, Jairo A. del Rio wrote:
...
|Hi list! I've tried adapting the following code for continued fractions:|
||
|%https://tex.stackexchange.com/questions/73195/how-to-typeset-a-continued-fra...
\documentclass{article}\usepackage{amsmath}\begin{document}\newcommand*{\cofrac}[2]{%{%\rlap{$\dfrac{1}{\phantom{#1}}$}%\genfrac{}{}{0pt}{0}{}{#1+#2}%}%}\[a_0 
+ 
\cofrac{a_1}{\cofrac{a_2}{\cofrac{a_3}{\genfrac{}{}{0pt}{0}{}{\ddots}}}}\]\end{document}
|
|As I could read from the mailing list, ConTeXt no longer supports 
\genfrac, so I've tried
|
|the following using \definemathfraction
\definemathfraction[gefrac][cfrac]
\setupmathfraction[gefrac][rule=no]
\def\cofrac#1#2{%
   {%
     \rlap{\cfrac{1}{\displaystyle\phantom{#1}}}%
     \gefrac{}{\displaystyle\gefrac{#1+}{}#2}%
   }%
}
\def\cofracnorule#1#2{%
{%
\rlap{\gefrac{\displaystyle\phantom{1}}{\displaystyle\phantom{#1}}}%
\gefrac{}{\displaystyle\gefrac{#1}{}#2}%
}%
}
\def\endfrac#1{\cofracnorule{#1}{\phantom{1}}}
\startTEXpage
\startplacefigure[location=force,number=no]
\externalfigure[cofrac.png]
\stopplacefigure
\startformula
\alpha +
\cofrac{\alpha'}{\cofrac{\alpha''}{\cofrac{\alpha'''}{{\endfrac{\ddots}}}}} 
\frac{1}{\alpha'''}
\stopformula
\stopTEXpage
|
|Mmm, superscripts and fraction rules superpose, so indeed something is 
wrong. Any ideas or references to a better result?
|
In the next version this will look okay:
\definemathfraction
   [gefrac]
   [d:frac]

\setupmathfraction
   [gefrac]
   [mathstyle=display,
    alternative=inner,
    rule=hidden]

\unexpanded\def\cofrac#1#2{%
     \rlap{\cfrac{1}{\phantom{#1}}}%
     \gefrac{}{\gefrac{#1+}{}#2}%
}

\unexpanded\def\endfrac#1{%
     \rlap{\phantom{\cfrac{1}{#1}}}%
     \gefrac{}{#1}%
}

\starttext

\startTEXpage
\startformula \showmakeup[kern]
         \alpha
         +
         \cofrac {\alpha'}
             {\cofrac {\alpha''}
                 {\cofrac {\alpha'''}
                     {\endfrac {\ddots}}}}
         +
         \frac{1}{\alpha'''}
     \stopformula
\stopTEXpage

\stoptext


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