Cfrgtkky

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?

$$...$$ is obsolete, see Why is [ … ] preferable to $$.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}

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}

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

letoldequationequation

letoldendequationendequation



renewenvironment{equation}

  {linenomathNonumbersoldequation}

  {oldendequationendlinenomath}

before begin{document}.

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

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. 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}