Why doesn't lineno number a paragraph when it is followed by an indented equation?

Question

While searching for the source of missing line numbers, I realized that paragraphs followed immediately by an equation have no line number, but this is fixed when a space is included,

e.g. the following document has no line numbers:

\documentclass[12pt]{article}
\usepackage{amsmath}
\usepackage{lineno}
\linenumbers
\begin{document}
Lorem ipsum dolor sit amet, consectetur adipiscing elit: 
$$1+1=2$$ 
\end{document}

But this one does:

\documentclass[12pt]{article}
\usepackage{amsmath}
\usepackage{lineno}
\linenumbers
\begin{document}
Lorem ipsum dolor sit amet, consectetur adipiscing elit: 

$$1+1=2$$ 
\end{document}

The only difference is the space above the equation.

Why is this the case (and is there a simple workaround)?
Is it incorrect to include an indented equation in a paragraph, or is this just a 'feature' of lineno?

score 33 · Answer 1 · edited Dec 05 '17 at 15:38

33

For line numbering to be done correctly the math environments has to be wrapped using the \begin{linenomath*} and \end{linenomath*} code:

\documentclass[12pt]{article}
\usepackage{amsmath}
\usepackage{lineno}
\linenumbers
\begin{document}
For line numbering to be done correctly the math environments has to be wrapped using the ''linenomath`` code as follows: 

\begin{linenomath*}
    \begin{equation}
        a^2=b^2+c^2
    \end{equation}
\end{linenomath*}
some text here some text here  some text here some text here some text here some text here some text here some text here some text here some text here some text here some text here some text here some text here some text heresome text here. 
\end{document}

enter image description here

edited Dec 05 '17 at 15:38

Stefan Pinnow

29,535

answered May 11 '15 at 16:53

Bamzi

343

3

This is particularly valuable, because it works for the AMS align environment, too! – AJK Nov 21 '15 at 00:41
What's the difference between having linenomath and not having linenomath? – Y. zeng May 22 '22 at 01:59

score 27 · Accepted Answer · edited Jul 03 '22 at 10:40

27

$$...$$ is obsolete, see Why is \[ ... \] preferable to $$ ... $$?. If you use the correct LaTeX displayed math environment, the numbering works without the empty line:

\documentclass[12pt]{article}
\usepackage{amsmath}
\usepackage{lineno}
\linenumbers
\begin{document}
Lorem ipsum dolor sit amet, consectetur adipiscing elit: 
\[1+1=2\] 
\end{document}

enter image description here

edited Jul 03 '22 at 10:40

user202729

7,143

answered Aug 15 '11 at 20:56

Stefan Kottwitz

231,401

thank you, is $ also obsolete? – David LeBauer Aug 15 '11 at 21:04
3

@David: that's true, see: Are $ and $ preferable to $. At least: $ ... $ is LaTeX syntax, so better supported in LaTeX. $...$ is plain TeX. However, usually both work well, many prefer $...$ because it's easier to write or just classic. – Stefan Kottwitz Aug 15 '11 at 21:09
3

@David: $ and $ are fragile by default. So, as Will Robertson said, don't use them unless you use fixltx2e package. And the default $ and $ have very few advantages compared with $. – Leo Liu Aug 16 '11 at 05:05
@StefanKottwitz, what could I do if I need numbered equations? – Sigur Apr 03 '13 at 20:08
@Sigur Use an equation environment. – Stefan Kottwitz Apr 03 '13 at 20:37
@StefanKottwitz, thanks. I noticed this problem when I tried to use the stared version of equation. So with equation both lines above and below are numbered except the line with the equation contents which has its equation number in parenthesis. If I use equation* to remove the equation number, then the line above the equation has no number and the line below has. – Sigur Apr 03 '13 at 21:51

score 24 · Answer 3 · edited Dec 05 '17 at 15:37

24

Mathematics environments need to be wrapped by \begin{linenomath*} and \end{linenomath*} as mentioned in Bamzi's answer.

A quick way to change all your equations is to renew the equation environment by adding the code

\let\oldequation\equation
\let\oldendequation\endequation

\renewenvironment{equation}
  {\linenomathNonumbers\oldequation}
  {\oldendequation\endlinenomath}

before \begin{document}.

edited Dec 05 '17 at 15:37

Stefan Pinnow

29,535

answered Dec 05 '17 at 15:10

R.M

341
2
3

Welcome to TeX.SX! – Bobyandbob Dec 05 '17 at 15:18
3

I'd say this is the most convenient answer. Thanks! – Yollanda Beetroot Oct 18 '18 at 10:36
2

This answer should be upvoted to top. Definitely. – WDC Nov 26 '18 at 03:19
How do we apply lineno with \begin{equation*} and \end{equation*} The above does not seem to work for me for unsing lineno on paragraphs where I have unnumbered equations. – user3236841 Jul 26 '22 at 23:59

score 3 · Answer 4 · edited May 25 '19 at 09:14

As @Denis has said, the mathlines option can be used in some cases (for article, but not for iopart, for example). If you do so, and you are also using the amsmath package, be sure to load lineno after amsmath. Sometimes other packages load amsmath, be aware of that; you can check the log file to see this. This MWE can be used to easily see the effect of that change:

\documentclass{article}
% \usepackage[mathlines]{lineno}
\usepackage{amsmath}
\usepackage[mathlines]{lineno}

\begin{document}
    \linenumbers

    Line number

    No line number if lineno is loaded before amsmath!
    \begin{equation}
        x = y
    \end{equation}

    Line number
\end{document}

score 2 · Answer 5 · answered Dec 23 '15 at 15:33

2

Use the mathlines option for lineno and write:

\begin{linenomath}
\begin{align*}
z_{1}&=x_{1}+y_{1}\\
z_{2}&=x_{2}+y_{2}
\end{align*}
\end{linenomath}

to obtain

answered Dec 23 '15 at 15:33

Denis

5,267

score 2 · Answer 6 · answered Mar 24 '22 at 02:21

2

The answer from Stefan Pinnow fixed the equation command. Use this to fix the align command in the same style:

\let\oldalign\align
\let\oldendalign\endalign
\renewenvironment{align}
  {\linenomathNonumbers\oldalign}
  {\oldendalign\endlinenomath}

answered Mar 24 '22 at 02:21

user267006

21
1

2

Your answer is basically a duplicateof R.M asnwer here – Roland Mar 24 '22 at 03:57
How do we apply lineno with \begin{align*} and \end{align*} The above does not seem to work for me for using lineno on paragraphs where I have unnumbered equations – user3236841 Jul 27 '22 at 00:39
@Roland no it's not, this answer says explicitely that it is to fix the align command – Tropilio Aug 10 '23 at 15:10

Why doesn't lineno number a paragraph when it is followed by an indented equation?

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