Alignment of math operators in table environment

Question

I have to reproduce a part of the following figure

Here is my code

\documentclass[a4paper,12pt]{article}
\usepackage{graphicx}
\usepackage{subcaption}

\begin{document}
\begin{figure}[htb]
\centering
  \begin{tabular}{@{}cccc@{}}
    \includegraphics[width=.23\textwidth]{example.pdf} =  &
    \includegraphics[width=.23\textwidth]{example0.pdf} + &
    \includegraphics[width=.23\textwidth]{example1.pdf} + &
    \includegraphics[width=.23\textwidth]{example2.pdf} + &
                                +                     &
    \includegraphics[width=.23\textwidth]{example3.pdf} +&
    \includegraphics[width=.23\textwidth]{example4.pdf} +&
    \includegraphics[width=.23\textwidth]{example5.pdf} +&
                                                      &
    \includegraphics[width=.23\textwidth]{example6.pdf} +&
    \includegraphics[width=.23\textwidth]{example7.pdf} +&  
    \includegraphics[width=.23\textwidth]{example8.pdf} &
  \end{tabular}
  \caption{This is   some figure side by side}
\end{figure}
\end{document}

I get the following output

I would like to know how I can alligh the math operators (+,=) so I can get them in the middle

Thanks and Regards,

Fowaz

Perhaps related http://tex.stackexchange.com/q/12382/12571 – JLDiaz Oct 14 '15 at 18:16 — JLDiaz, Oct 14 '15 at 18:16

score 4 · Answer 1 · answered Oct 14 '15 at 18:26

I did several things. I edited to force line breaks in the tabular, where appropriate, I used \raisebox to achieve vertical centering of math operators, which I also cast into math mode for proper spacing.

\documentclass[a4paper,12pt]{article}
\usepackage[demo]{graphicx}
\usepackage{subcaption}
\newcommand\IG[1]{\raisebox{-.5\height}{%
  \includegraphics[width=.23\textwidth]{#1}}}
\begin{document}
\begin{figure}[htb]
\centering
\tabcolsep0pt
\renewcommand\arraystretch{7}
  \begin{tabular}{@{}cccc@{}}
    \IG{example.pdf}${}={}$&
    \IG{example0.pdf}${}+{}$&
    \IG{example1.pdf}${}+{}$&
    \IG{example2.pdf}${}+{}$\\&
    \IG{example3.pdf}${}+{}$&
    \IG{example4.pdf}${}+{}$&
    \IG{example5.pdf}${}+{}$\\&
    \IG{example6.pdf}${}+{}$&
    \IG{example7.pdf}${}+{}$&  
    \IG{example8.pdf} 
    \phantom{${}+{}$}
  \end{tabular}
  \caption{This is   some figure side by side}
\end{figure}
\end{document}

score 4 · Answer 2 · answered Oct 14 '15 at 19:34

You may wish to set this like a regular equation, using adjustbox's valign=m to set the images with a vertical anchor point in the middle:

\documentclass{article}
\usepackage[export]{adjustbox}
\usepackage{amsmath}

\let\oldincludegraphics\includegraphics

\begin{document}
\begin{figure}
  \renewcommand{\includegraphics}[2][]{\oldincludegraphics[valign=m,width=.23\textwidth,#1]{#2}}
  \begin{align*}
    \includegraphics{example-image-1x1} &=
    \includegraphics{example-image-1x1} +
    \includegraphics{example-image-1x1} +
    \includegraphics{example-image-1x1} + {} \\
    & \phantom{{}={}}
    \includegraphics{example-image-1x1} +
    \includegraphics{example-image-1x1} +
    \includegraphics{example-image-1x1} + {} \\
    & \phantom{{}={}}
    \includegraphics{example-image-1x1} +
    \includegraphics{example-image-1x1} +
    \includegraphics{example-image-1x1}
  \end{align*}
  \vspace{-\belowdisplayskip}
  \caption{This is some figure side by side}
\end{figure}

\end{document}

The above approach mimics typical mathematical typesetting in terms of spacing around operators, seeing as your are doing exactly that.

Good answer, but I disagree with the idea of redefining \includegraphics, even locally. — egreg, Oct 14 '15 at 20:11

score 3 · Answer 3 · answered Oct 14 '15 at 18:29

Similarly, but with help of adjustbox and `array package:

\documentclass[a4paper,12pt]{article}
\usepackage{graphicx}
\usepackage{subcaption}

\usepackage{array}
\usepackage[export]{adjustbox}

    \begin{document}
\begin{figure}[h]
\centering
  \begin{tabular}{@{}*{4}{p{0.23\textwidth}>{$}c<{$}}@{}}
    \includegraphics[width=\hsize,valign=m]{example-image-a} &=&
    \includegraphics[width=\hsize,valign=m]{example-image}   &+& 
    \includegraphics[width=\hsize,valign=m]{example-image}   &+& 
    \includegraphics[width=\hsize,valign=m]{example-image}   &+  \\[7ex]
%
    &   &
    \includegraphics[width=\hsize,valign=m]{example-image}   &+&
    \includegraphics[width=\hsize,valign=m]{example-image}   &+&
    \includegraphics[width=\hsize,valign=m]{example-image}   &  \\
  \end{tabular}
 \caption{This is   some figure side by side}
\end{figure}
    \end{document}

score 3 · Accepted Answer · answered Oct 14 '15 at 20:11

Precise alignment to the plus sign is obtained by enveloping the \includegraphics in \vcenter, which is automatically done by array (since we're in math mode) without optional arguments.

\documentclass{article}
\usepackage{amsmath}
\usepackage{graphicx}

\newcommand{\vcenterincludegraphics}[2][]{%
  \begin{array}{@{}c@{}}
  \includegraphics[#1]{#2}
  \end{array}%
}


\begin{document}
\begin{figure}
\centering

$\begin{aligned}
  \vcenterincludegraphics[width=.20\textwidth]{example-image-1x1} ={}&
  \vcenterincludegraphics[width=.20\textwidth]{example-image-1x1} +
  \vcenterincludegraphics[width=.20\textwidth]{example-image-1x1} +
  \vcenterincludegraphics[width=.20\textwidth]{example-image-1x1} + {} \\
  &
  \vcenterincludegraphics[width=.20\textwidth]{example-image-1x1} +
  \vcenterincludegraphics[width=.20\textwidth]{example-image-1x1} +
  \vcenterincludegraphics[width=.20\textwidth]{example-image-1x1} + {} \\
  &
  \vcenterincludegraphics[width=.20\textwidth]{example-image-1x1} +
  \vcenterincludegraphics[width=.20\textwidth]{example-image-1x1} +
  \vcenterincludegraphics[width=.20\textwidth]{example-image-1x1}
\end{aligned}$

\caption{This is some figure side by side}

\end{figure}

\end{document}

I changed .23 to .20 to avoid overfull lines (the code has been taken, with modifications, from Werner's answer).

Of course the definition

\newcommand{\vcenterincludegraphics}[2][]{%
  \vcenter{\hbox{%
    \includegraphics[#1]{#2}
  }}%
}

would be more efficient, perhaps at the expense of clarity.

score 0 · Answer 5 · edited Jul 14 '17 at 01:34

I would use \raisebox on every "+"sign

\includegraphics[width=.23\textwidth]{example.pdf} \raisebox{1.1cm}{=}  &
\includegraphics[width=.23\textwidth]{example0.pdf} \raisebox{1.1cm}{+} &
\includegraphics[width=.23\textwidth]{example1.pdf} \raisebox{1.1cm}{+} &
\includegraphics[width=.23\textwidth]{example2.pdf} \raisebox{1.1cm}{+} &
                            \raisebox{1.1cm}{+}

You gotta iterate the height of the sign for different desired results.

Alignment of math operators in table environment

5 Answers5