tikz resized in table cell

Question

a) How can I resize the tikz picture to fit inside the tabular cell ?

b) How can I center the first row horizontally?

This is what I've until now:

\documentclass{article}
\usepackage[a4paper]{geometry}

\usepackage[utf8]{inputenc} % accents
\usepackage{verbatim} % \begin{comment}
\usepackage{tcolorbox}

\usepackage{amsfonts,amsmath}

\usepackage{tikz}

\newcommand{\mmRationalPie}[1]{
\def\angle{#1}
\def\radius{1}
\def\color{blue}

\begin{tikzpicture}[]
  \draw[fill=red,draw=red] (0,0) -- (0:\radius) arc (0:\angle:\radius) -- cycle;
  \draw (0,0) -- (\angle:\radius) arc (\angle:360:\radius) -- cycle;
\end{tikzpicture}
}

\begin{document}


\begin{tabular}[t]{ | p{1cm} | p{1cm} |}
$ \frac{1}{3} $ & $ \frac{2}{3} $ \\
\hline 
\mmRationalPie{120} & \mmRationalPie{240}
\end{tabular}


\end{document}

clarification: it is better if, in order to change the sizes, it is not necessary modify both, the tikz commands and the tabular characteristics.

Answer 1

The problem is that you're setting the radius of the circle to be 1cm and the table column width to 1cm too. You should set the circle radius to be less than 0.5cm (less because there is inner spacing inside the tabular cells).

To center the first row you have to use centered column specifiers, if you wish to set the column width than you can make a new column specifier using the array package, like in this answer. If you are ok with leaving the width for LaTeX to determine, than the usual c can manage it. I've used TikZ pic's mechanism instead of your command, as that's more flexible (you can call options with it).

Finally, consider not using vertical rules, in this example I removed the vertical rules and used \toprule, \midrule and \bottomrule from booktabs, they offer better spacing between rule and text. The result:

EDIT: since the OP wants to have the circle radius to follow the column width I used the definition of \pieradius as a function of \linewidth. But the radius can also be set locally through the key pie radius=<dim>

MWE:

\documentclass{article}
\usepackage{tikz,array,booktabs,amsmath}
\newcolumntype{C}[1]{>{\centering\let\newline\\\arraybackslash}m{#1}}

\tikzset{
pie radius/.store in=\pieradius,
pie radius=0.45*\linewidth,
pics/rational pie/.style={code={\filldraw[red] (0,0) -- (0:.45*\pieradius) arc (0:#1:.45*\pieradius) -- cycle;%
      \draw (0,0) -- (#1:.45*\pieradius) arc (#1:360:.45*\pieradius) -- cycle;}}
}

\begin{document}
  \begin{tabular}[t]{C{1cm} C{2cm}}
  \toprule
  $ \dfrac{1}{3} $ & $ \dfrac{2}{3} $ \\
  \midrule
  \tikz\pic[pie radius=0.2cm]{rational pie=120}; & \tikz\pic{rational pie=240}; \\
  \tikz\pic{rational pie=120}; & \tikz\pic{rational pie=240}; \\
  \bottomrule
  \end{tabular}
\end{document}

Answer 2

To resize the drawing without changing the original definition, use the resize command of the form \resizebox{width}{height}{object} choosing the required width/height as you wish.

\documentclass{article}
\usepackage[a4paper]{geometry}
\usepackage[utf8]{inputenc} % accents
\usepackage{verbatim} % \begin{comment}
\usepackage{tcolorbox}
\usepackage{amsfonts,amsmath}
\usepackage{tikz,array,booktabs}

\newcommand{\mmRationalPie}[1]{
\def\angle{#1}
\def\radius{1}
\def\color{blue}
\begin{tikzpicture}[]
  \draw[fill=red,draw=red] (0,0) -- (0:\radius) arc (0:\angle:\radius) -- cycle;
  \draw (0,0) -- (\angle:\radius) arc (\angle:360:\radius) -- cycle;
\end{tikzpicture}
}

\begin{document}    
\newcolumntype{C}[1]{>{\centering\arraybackslash}p{#1}}

\begin{tabular}[t]{ C{1cm} C{1cm} }
\toprule
$ \frac{1}{3} $ & $ \frac{2}{3} $ \\ \midrule 
\resizebox{1cm}{!}{\mmRationalPie{120}} & \resizebox{1cm}{!}{\mmRationalPie{240}}\\
\bottomrule
\end{tabular}

\end{document}

Answer 3

Use the scale option of tikzpicture. Furthermore, avoid empty lines in the definition of the command, as well as spurious spaces because of line ends. I'd center the fraction and the diagram, either by changing the column type to c or by using multicolumn to change the type individually for single entries; in the code below I illustrate both variants.

\documentclass{article}
\usepackage{tikz}

\newcommand{\mmRationalPie}[1]{%
\def\angle{#1}%
\def\radius{1}%
\def\color{blue}%
\begin{tikzpicture}[scale=0.5] % <<<<<<<<<<<<<<<<<<<<<<<<<<<
  \draw[fill=red,draw=red] (0,0) -- (0:\radius) arc (0:\angle:\radius) -- cycle;
  \draw (0,0) -- (\angle:\radius) arc (\angle:360:\radius) -- cycle;
\end{tikzpicture}%
}

\begin{document}

\begin{tabular}[t]{ | c | p{1cm} |}
$ \frac{1}{3} $ & \multicolumn{1}{c|}{$\frac{2}{3}$} \\
\hline 
\mmRationalPie{120} & \multicolumn{1}{c|}{\mmRationalPie{240}}
\end{tabular}

\end{document}

Answer 4

Here is a solution based on this answer to "How to scale a tikzpicture to \textwidth", which uses an idea due to Ulrike Fischer. It is recommended not to scale a tikz-picture externally, therefore the tikz-picture is typeset twice, once unscaled and then with an appropriate scaling factor computed on the basis of the unscaled width.

I did not remove the vertical rules to show that for some reason the tikz-picture in the left column has some extra space (originating already from the picture) such that the circle turns out smaller than the right one. But this is another question ...

\documentclass{article}
\usepackage{tikz}
\usepackage{environ}
\makeatletter
\newsavebox{\measure@tikzpicture}
\NewEnviron{scaletikzpicturetowidth}[1]%
  {\def\tikz@width{#1}%
   \def\tikzscale{1}%
   \begin{lrbox}{\measure@tikzpicture}%
     \BODY
   \end{lrbox}%
    \pgfmathparse{#1/\wd\measure@tikzpicture}%
    \edef\tikzscale{\pgfmathresult}%
    \BODY
  }
\makeatother

\newcommand{\mmRationalPie}[1]%
  {\begin{scaletikzpicturetowidth}{\linewidth}%
     \def\pieangle{#1}%
     \def\pieradius{1}%
     \begin{tikzpicture}[scale=\tikzscale]
       \draw[fill=red,draw=red] (0,0) -- (0:\pieradius) arc (0:\pieangle:\pieradius) -- cycle;
       \draw (0,0) -- (\pieangle:\pieradius) arc (\pieangle:360:\pieradius) -- cycle;
     \end{tikzpicture}%
   \end{scaletikzpicturetowidth}%
  }

\begin{document}

\begin{tabular}[t]{| p{1cm} | p{1cm} |}
\multicolumn{1}{|c|}{$\frac{1}{3}$} & \multicolumn{1}{c|}{$\frac{2}{3}$} \\
\hline 
\mmRationalPie{120} & \mmRationalPie{240}
\end{tabular}

\end{document}

Answer 5

I wanted to do this with tikzscale and couldn't, so this is semi-done.

Very important: never write things like \def\color{blue} unless you really, really want things to break!

I wouldn't do this this way at all, but since you seem determined to do so, at least avoid the most obvious sources of trouble.

\documentclass{article}
\usepackage[a4paper]{geometry}
\usepackage[utf8]{inputenc}
\usepackage{array}
\usepackage{tikz}

\newcolumntype{C}[1]{>{\centering\arraybackslash}p{#1}}

\tikzset{%
  rat pie/.search also={/tikz/},
  rat pie/.cd,
  angle/.store in=\ratpieangle,
  radius/.store in=\ratpieradius,
  colour/.store in=\ratpiecolour,
  angle=60,
  radius=1,
  colour=blue,
}
\newcommand{\mmRationalPie}[1]{%
  \tikzset{%
    rat pie/angle=#1,
    rat pie/radius=.45\linewidth,
  }%
  \begin{tikzpicture}[baseline=(o)]
    \draw [fill=\ratpiecolour, draw=\ratpiecolour] (0,0) coordinate (o) -- (0:\ratpieradius ) arc (0:\ratpieangle:\ratpieradius) -- cycle;
    \draw (0,0) -- (\ratpieangle:\ratpieradius) arc (\ratpieangle:360:\ratpieradius) -- cycle;
  \end{tikzpicture}%
}

\begin{document}

\begin{tabular}[t]{ | C{1cm} | C{1cm} |}
  $ \frac{1}{3} $ & $ \frac{2}{3} $ \\
  \hline
  \mmRationalPie{120} & \mmRationalPie{240}\\
  \mmRationalPie{240} & \mmRationalPie{30}\\
\end{tabular}

\end{document}