2

I'm trying to write a dot over a subscript - like

    f_{\dot{x}}

My problem is that this comes out looking all wrong. The dot is inside the x, it's just messy. Does anyone know of a way to do this?

P.S I'm doing this because I want to write the euler-lagrange equations in the more compact form

    f_{x}=\dot{f_{\dot{x}}}

so I need a method that will accompany another dot on top of the one in the subscript. Any help would be appreciated.

Edit: Mico answered this below to all who have the same issue! Thanks Mico!

  • 2
    You can do f^{}_{\dot{x}}, with a dummy superscript. It's unclear what you want to achieve with f_{x}=\dot{f_{\dot{x}}}: can you show an approximate representation or point to some image? – egreg May 5 '17 at 21:20
  • Do you load the amsmath package? Please confirm. – Mico May 5 '17 at 21:30
  • Thank you all! Mico answered with exactly what I needed below. – vladimir karposkavitch May 5 '17 at 21:39
3

If you change from \dot{f_{\dot{x}}} to \dot{f}_{\dot{x}}, both dots will be placed correctly.

enter image description here

\documentclass{article}
\begin{document}
$f_{x}=\dot{f}_{\dot{x}}$
\end{document}

Addendum: A second MWE, which shows the OP's formula, the improvement suggested above, and a possible further improvement on.

enter image description here

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{tabular}{ccc}
bad & good & best(?) \\[1ex]
$\dot{f_{\dot{x}}}$ & $\dot{f}_{\dot{x}}$ & $\dot{f}^{}_{\!\dot{x}}$ 
\end{tabular}
\end{document}
  • 1
    Damn you've beaten me by a split second! :) – Moriambar May 5 '17 at 21:18
  • 1
    very good for your work +1. – Sebastiano May 5 '17 at 21:31
  • Thank you! Exactly what I was looking for. Much obliged to all who commented! – vladimir karposkavitch May 5 '17 at 21:38
1

You could do something clunky like this:

\documentclass{article}
\usepackage{amsmath}
\newcommand{\mydot}[1]{\raisebox{-0.5ex}{\scriptsize$\dot{#1}$}}

\begin{document}
\[
f_{\dot x}  \quad f_{\mydot{x}}
\]
\end{document}

enter image description here

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.