# Fractions inside the pieces

I am wondering if it is possible to create a pie chart with fractions instead of the default numbers inside the pie pieces (for one piece or for all pieces)? Thank you for your help.

Code:

\documentclass[fleqn,12pt, a4paper]{scrartcl}

\usepackage{tikz}
\usepackage{pgf-pie}

\begin{document}
\begin{tikzpicture}

%%I want 1/6 instead of 1 inside the pieces:
\pie[sum=auto]
{1/,1/,1/,1/,1/,1/}

\end{tikzpicture}
\end{document}


EDITED to provide true \frac capability, all using the native keys provided by the pgf-pie package. Three versions are shown:

1. \frac

2. \displaystyle\frac, and

3. #1/#2

First thing, is the fraction has to be provided in braces as {a/b}, so that tikz can evaluate it for calculating the pie-slice size. Then, in order to get the label as a \frac, one uses before number and after number keys to basically unpack and evaluate the fraction not as a math calculation, but rather as math typesetting.

I figured out this solution by looking at the guts of the pgf-pie package and realized that the macros \beforenumber and \afternumber were part of the typesetting. I, therefore, had to figure out how to define the keys to expand what I needed expanded, in order to evaluate \beforenumber\p\afternumber as, for example, \frac{1}{6}, when \p is defined as {1/6}.

The MWE:

\documentclass[fleqn,12pt, a4paper]{scrartcl}

\usepackage{tikz}
\usepackage{pgf-pie}

\def\myfrac#1{\expandafter\expandafter\expandafter\expandafter\expandafter%
\expandafter\expandafter\myfracaux\expandafter\expandafter\expandafter#1}
\def\myfracaux#1/#2\relax{$\piestyle\frac{#1}{#2}$}
\def\piestyle{\textstyle}
\begin{document}

\begin{tikzpicture}
%%I want 1/6 instead of 1 inside the pieces:
\pie[sum=auto, before number=\myfrac, after number=\relax]
{{1/2}/,{3/16}/,{1/4}/,{1/16}/}
\end{tikzpicture}
%
\def\piestyle{\displaystyle}
\begin{tikzpicture}
%%I want 1/6 instead of 1 inside the pieces:
\pie[sum=auto, before number=\myfrac, after number=\relax]
{{1/6}/,{1/6}/,{1/6}/,{1/6}/,{1/6}/,{1/6}/}
\end{tikzpicture}

\begin{tikzpicture}
%%I want 1/6 instead of 1 inside the pieces:
\pie[sum=auto]
{{1/6}/,{1/6}/,{1/6}/,{1/6}/,{1/6}/,{1/6}/}
\end{tikzpicture}
\end{document}


• Thanks for the quick answer, it helped a lot. I tried to make the fraction looks more mathematically with "\frac{1}{2}", but it does not work with pgf-pie. Is there another way to label the pieces with \frac{}{}? Thank you for answering. Oct 23 '18 at 12:48
• @KilianHof I figured it out, looking at the guts of the pgf-pie package Oct 23 '18 at 16:46