2

I have many equations in a document. I used \ [ \ ] for start and end of a math equation. I labeled the equation with \label{eq:1}, referenced with ~\eqref{eq:1}. It was showing just the section number. Can't we label and reference equations defined with \ [ and \ ] and auto numbering enabled ? Is using 'equation' environment the only way ? I needed equation to be numbered by (1) and (1) be displayed at \eqref{eq:1}. Here's my code and output

\documentclass[a4paper,12pt]{report} \usepackage{amsfonts} % Math package \usepackage{amsmath} % The graphicx package allows you to import JPG and PDF images \usepackage[pdftex]{graphicx} \usepackage[T1]{fontenc} \usepackage{geometry} \geometry{verbose,a4paper,tmargin=15mm,bmargin=30mm,lmargin=20mm,rmargin=20mm} \usepackage{graphics} \usepackage{setspace} \usepackage{cite} \usepackage{natbib} \usepackage{lettrine} \setcounter{secnumdepth}{5} \setcounter{tocdepth}{5} \onehalfspacing \makeatletter \newcommand{\LyX} {L\kern-.1667em\lower.25em\hbox{Y}\kern-.125emX\spacefactor1000} \makeatother \begin{document} \chapter{literature} \section{Section 1} \subsection{subsection 1} \begin{equation} V^{m\times n}=G^{m\times3p}P^{3p\times n} \label{eq:1} \end{equation} Where `$m$' representing number of channels, `$n$' time samples considered, `$p$' number of dipoles considered. ~\eqref{eq:1}. \end{document}

enter image description here

Improve this question
4
  • 2
    if there is no equation number what text would you want \ref to make? if you don't want the automatic numbering sequence you can use the amsmath command \tag to supply any other label text which can then be used with label/ref Commented Nov 10, 2016 at 16:25
  • 1
    Equation numbering is done automatically by label number.. But with \ [ \ ] equations are not being numbered. Commented Nov 10, 2016 at 16:30
  • yes that is the only difference between \[ and \begin{equation} you use \[ if you do not want a number. what is your question? Commented Nov 10, 2016 at 16:34
  • Note that is a bad idea to use a number in the argument of \label such as \label{eq;1} it works but is confusing as the number is unrelated to any number that is printed, it is just an internal identifier. Commented Nov 10, 2016 at 16:36

1 Answer 1

Reset to default
4

The equation number is not set by \label, but instead by the equation environment. To reference something, you need to have a label set in the document that is visible to the readers. This is done by equation, but not by \[...\]. So, yes, you need equation (or some other display math environment that also enumerates):

enter image description here

\documentclass{article} \usepackage{amsmath,lipsum} \begin{document} \lipsum[1] \begin{equation} V^{m \times n} = G^{m \times 3p} P^{3p \times n} \label{eq:1} \end{equation} Where `$m$' represents the number of channels, `$n$' time samples considered, and `$p$' the number of dipoles considered. See~\eqref{eq:1}. \end{document}

Additional notes:

  • No blank lines around the equation environment as it forms part of the paragraph structure, and affects the indentation of subsequent paragraphs (but this may be personal preference).

  • Using a backtick and apostrophe as a pair for quoting.

Improve this answer
8
  • Ok, thanks for the information. But when equation is under a section, section number is used for referencing instead of (1) by latex. Commented Nov 10, 2016 at 16:45
  • 1
    @WupadrastaSantosh: You need to place \label inside the equation environment. Commented Nov 10, 2016 at 16:45
  • Still, equation is labelled as (2.1), section numbering but not as (1). Commented Nov 10, 2016 at 17:17
  • @WupadrastaSantosh: Can you supply a small document that replicates this (unbelievable) behaviour? Something that starts with \documentclass, ends with \end{document} has (say) two sections and an equation environment with a \label in it that I can copy-and-paste-and-compile and see what you're seeing? Perhaps use Pastebin. Commented Nov 10, 2016 at 17:19
  • I have included in the code which behaves unbelievably, in the question.. Commented Nov 10, 2016 at 17:31

You must log in to answer this question.

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.