7

enter image description here

Hi do you know how I can produce this symbol in latex? Only the bar through the letter i need I know the rest. And i need something that works on math mode for sure. I tried using \sout with ulem package combined with \ddots but didn't work.

\documentclass[12pt]{article} 
\usepackage[margin=1in]{geometry} 
\usepackage{amsmath,amsthm,amssymb,empheq,caption}
\usepackage{graphicx}
\usepackage{siunitx}
\usepackage{mathtools}
\usepackage{float}
\usepackage{ulem}

\begin{document}

   \begin{equation}
     \frac{dJ}{dt}=-\frac{2}{5}\frac{G}{c^5}\epsilon_{ijk}
       \Big\langle{\sout{\ddot{I}_{jm}}\sout{\dddot{I}_{km}}}\Big\rangle
   \end{equation}

\end{document}

Output of the code

enter image description here

Arun Debray
  • 7,126
  • 2
  • 30
  • 54
Tcm
  • 71
  • Welcome to TeX.SX!! It is better to post a full minimal working example that starts with a \documentclass command, has a minimal preamble and then \begin{document}...\end{document}. Unless the problem is a compilation error, the code should compile and be as small as possible to demonstrate your problem. This makes it much easier for people to help you --- and much more likely that they will! –  Mar 04 '16 at 20:46
  • You can highlight code in your post using back-ticks. For code-blocks indent them by four spaces or use the {} on the gui. –  Mar 04 '16 at 20:46
  • http://tex.stackexchange.com/questions/20609/strikeout-in-math-mode this shows a similar question. Does the \hcancel offer a solution for you? – Douwe66 Mar 04 '16 at 20:49
  • I think it's better now :). I don't know if I am using \sout correct. only the bar in the middle I want – Tcm Mar 04 '16 at 21:10
  • Gravitational radiation equations? –  Mar 04 '16 at 21:15
  • yep :) angular momentum loss due to gr waves – Tcm Mar 04 '16 at 21:18

3 Answers3

7

Here's a possible solution working in all sizes.

\documentclass{article}
\usepackage{amsmath}
\usepackage{etoolbox}

% fix amsmath's \dddot
\patchcmd{\dddot}{#1}{\kern0pt #1}{}{}

\makeatletter
\DeclareRobustCommand{\barredI}{%
  \mathord{\vphantom{I}\mathpalette\@barredI\relax}%
}

\newcommand{\@barredI}[2]{%
  \ooalign{%
    \hidewidth\@barredIbar#1\hidewidth\cr
    $\m@th#1I$\cr
  }%
}

\newcommand{\@barredIbar}[1]{%
  \check@mathfonts
  \ifx#1\displaystyle
    \fontsize{\f@size}{\z@}%
    \def\@barredIbarkern{0.3}%
  \else
    \ifx#1\textstyle
      \fontsize{\f@size}{\z@}
      \def\@barredIbarkern{0.3}%
    \else
      \ifx#1\scriptstyle
        \fontsize{\sf@size}{\z@}
        \def\@barredIbarkern{0.4}%
      \else
        \fontsize{\ssf@size}{\z@}
        \def\@barredIbarkern{0.47}%
      \fi
    \fi
  \fi
  \usefont{OT1}{cmr}{m}{n}%
  \kern-\@barredIbarkern em 
  \raisebox{-.5ex}{\symbol{'26}}%
}
\makeatother

\begin{document}

$\barredI_{\barredI_{\barredI}}$ $I\barredI$

\bigskip

$\dddot{I}_{\!jk}\dddot{\barredI}_{\!jk}$

\end{document}

enter image description here

egreg
  • 1,121,712
4

You can adapt this answer to a similar question:

\documentclass{article}
\usepackage{amsmath}
\usepackage{calc}
\newsavebox\CBox
\newcommand\hcancel[2][0.5pt]{%
  \ifmmode\sbox\CBox{$#2$}\else\sbox\CBox{#2}\fi%
  \makebox[0pt][l]{\usebox\CBox}%  
  \rule[0.5\ht\CBox-#1/2]{\wd\CBox}{#1}}
\begin{document}

$\dddot{\hcancel{I}}_{jk} \dddot{\hcancel{I}}_{jk}$

\end{document}

enter image description here

Arun Debray
  • 7,126
  • 2
  • 30
  • 54
1

I found this question which seems to me similar. With it I suggest:

\documentclass[12pt]{article} 
\usepackage{amsmath} % here for \dot, \ddot, ... and \text command
\usepackage{soul} % here for \st command

\begin{document}

\begin{equation}
    \ddot{\mbox{\st{$I$}}}_{jm} % instead of \mbox you can use \text
\end{equation}

\end{document}

Be aware that you need to put a \mbox{} or \text{} (from the amsmath package) around the letter with the horizontal bar through. Inside the box I used $I$ again in order to keep the math font.

enter image description here

Compared to the other answers my solution has some disadvantages:

  • The dots are not correctly horizontally centered above of the character.
  • The bar/line in not correctly vertically centered (too low).

But there is an advantage too:

  • You don't need a lot of code and custom commands.