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→Binomial coefficients
= Fractions, Binomials, genfrac, continued fractions =
{{cmd|frac}} typeset fraction, according to the current style.Others commands enforce a certain style :* {{cmd|tfrac}} for text style* {{cmd|dfrac}} for display style* {{cmd|xfrac}} for script style.* {{cmd|sfrac}} and {{cmd|xxfrac}} for script of script style.* {{cmd|cfrac}} for continued style* {{cmd|vfrac}} for semi-horizontal style* {{cmd|hfrac}} for horizontal style <context source="yes">\starttabulate[|l|l|l|]\HL\NC {\bf Size or style} \NC {\bf Code} \NC {\bf Typesetting} \NC\NR\HL\NC math \NC \type{\frac{1}{3}} \NC \m{\frac{1}{3}} \NC\NR\NC display \NC \type{\dfrac{1}{3}} \NC \m{\dfrac{1}{3}} \NC\NR\NC script \NC \type{\xfrac{1}{3}} \NC \m{\xfrac{1}{3}} \NC\NR\NC scriptscript \NC \type{\sfrac{1}{3}} \NC \m{\sfrac{1}{3}} \NC\NR\NC scriptscript \NC \type{\xxfrac{1}{3}} \NC \m{\xxfrac{1}{3}} \NC\NR\NC semi-horizontal \NC \type{\vfrac{1}{3}} \NC \m{\vfrac{1}{3}} \NC\NR\NC horizontal \NC \type{\hfrac{1}{3}} \NC \m{\hfrac{1}{3}} \NC\NR\NC continued \NC \type{\cfrac{1}{3}} \NC \m{\cfrac{1}{3}} \NC\NR\NC text \NC \type{\tfrac{1}{3}} \NC \m{\tfrac{1}{3}} \NC\NR\stoptabulate </context> == Different behaviors for inline and display mode == <context source="yes">\startbuffer[frac]\frac{1}{2} + \dfrac{1}{2} - \sfrac{1}{2} - \xfrac{1}{2} - \xxfrac{1}{2} + \vfrac{1}{2} + \hfrac{1}{2} + \tfrac{1}{2}\stopbuffer \framed[frame=off,align=normal]{% <=== just to improve wiki renderingEach time, we display the different style: With \tex{startformula} (display mode)\startformula\getbuffer[frac]\stopformula With \tex{m} (inline mode): \m{\getbuffer[frac]}}</context> == Fractions of fractions == <context source="yes">\startbuffer[frac]\frac{1}{2} + \dfrac{1}{2} - \sfrac{1}{2} - \xfrac{1}{2} - \xxfrac{1}{2} + \vfrac{1}{2} + \hfrac{1}{2} + \tfrac{1}{2}\stopbuffer \framed[frame=off,align=normal]{% <=== just to improve wiki renderingNow fraction of fractions: With \tex{startformula} (display mode)\startformula \frac {\getbuffer[frac]} {\getbuffer[frac]}\stopformula With \tex{m} (inline mode) and \tex{frac}:\m{\frac {\getbuffer[frac]} {\getbuffer[frac]}} With \tex{m} (inline mode) and \tex{cfrac} (continued):\m{\cfrac {\getbuffer[frac]} {\getbuffer[frac]}}}</context> == Formatting with {{cmd|definemathfraction}} == Just an example from [https://www.mail-archive.com/ntg-context@ntg.nl/msg69987.html mailing list] <context source="yes">\startformula \frac {a} { \frac{b}{c} } \stopformula \definemathfraction [wfrac] [margin=.25em] \startformula \wfrac {a} { \frac{b}{c} } \stopformula</context> = Binomial coefficients ==
To write binomial coefficients you use any of {{cmd|binom}}, {{cmd|tbinom}} or {{cmd|dbinom}} (the latter two if you want to force text style or display style respectively). These commands are defined as fractions in ConTeXt, and can be set up with
{{cmd|setupmathfractions}}.
<texcodecontext source="yes">
\setuphead[chapter][align=middle]
\setuphead[section][style=\bfa]
\setuphead[subsection][style=\it]
\setuplayout[
\getbuffer
%\switchtobodyfont[lucidaot]%\subsubject{Lucida}%\getbuffer
\column[yes]
\setupmathfractionsdefinemathfraction[binomial] [binom] [fences=parenthesis,rule=no]\definemathfraction[tbinomial][binomial] [mathstyle=text]\definemathfraction[dbinomial] [binomial] [mathstyle=display] \startbuffer\type{\binomial{n}{k}}: $\binomial{n}{k}$\par\type{\tbinomial{n}{k}}: $\tbinomial{n}{k}$\par\type{\dbinomial{n}{k}}: $\dbinomial{n}{k}$\par\stopbuffer
\switchtobodyfont[modern]
\subject{With fences=parenthesis\tex{definemathfraction}}
\subsubject{Latin Modern}
\getbuffer
\getbuffer
%\switchtobodyfont[lucidaot]%\subsubject{Lucida}%\getbuffer
\stopcolumns
\stoptext
</texcodecontext>
The result of the code above, with the standalone from 2017-09-05 is given below.
[[File:binomialcoefficients.png|700px]]