Take the 2-minute tour ×
TeX - LaTeX Stack Exchange is a question and answer site for users of TeX, LaTeX, ConTeXt, and related typesetting systems. It's 100% free, no registration required.

When I have equations, as in

\begin{equation} ... \end{equation}

Can I arbitrarily assign the numbers to the equations? Instead of the usual order (1), (2), (3), ..., I'd like something like (1), (2.1), (2.2), (2.3), (3.1), (3.2), (4), ...

share|improve this question
2  
Is there some logic behind the numbering, or is it purely arbitrary? –  Werner Feb 8 '13 at 3:56
    
@Werner Thanks for your question. They are the equations under Theorem 1, Theorem 2, and so on. Is there a convenient way to do the numbering? –  Paul S. Feb 8 '13 at 4:06
    
@PaulS. see my update :) –  cmhughes Feb 8 '13 at 4:11

1 Answer 1

up vote 9 down vote accepted

Yes, absolutely, using the amsmath package and its \tag command.

A little example

\documentclass{article}
\usepackage{amsmath}

\begin{document}

\begin{equation}
  y=mx+b\tag{1.2}
\end{equation}
or
\begin{equation}
  y=mx+b\tag{duck}
\end{equation}
\end{document}

After reading your comment, if you want the equation number to inherit the theorem number, then you can use, for example,

\newtheorem{mytheorem}{Theorem}
\numberwithin{equation}{mytheorem}

and then you don't have to tag equations manually.

share|improve this answer
    
Yes, thank you! –  Paul S. Feb 8 '13 at 4:06

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

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