Equations are not centered by default on a featured template listed by overleaf

Question

I've been trying to work on Basic Academic Journal Article Template featured by Overleaf.

Although $$ a + b = c$$ is centered, the following equations are not centered:

\[ a + b = c \]
\begin{equation*}
    a + b = c
\end{equation*}
\begin{equation}
    a + b = c
\end{equation}

How do I revise the template to make all these equations centered by default?

Here is my project, which can be edited by anyone with the link. The original code in the project link is as follows.

\documentclass[fleqn,10pt,lineno]{olplainarticle}
\title{Example Article Title}
\author[1]{First Author}
\affil[1]{Address of first author}
\keywords{Keyword1, Keyword2, Keyword3}
\begin{abstract}
  abstract 
\end{abstract}
\begin{document}
\flushbottom
\maketitle
\thispagestyle{empty}
\section*{Mathematics}
$$ a + b = c $$
[ a + b = c ]
\begin{equation}
    a + b = c
\end{equation}
\begin{equation}
    a + b = c
\end{equation}
\end{document}

Welcome to TeX.SE. Please don't hide your code behind a link: once you change it, this question becomes useless. Trim your code down to the minimum that makes this happen, and then post that here. (Also, you've given write access to the world.) Templates are good for learning, but then you should start with a blank file and only add the things that you want. Also, see https://tex.stackexchange.com/questions/503/why-is-preferable-to — Teepeemm, Feb 05 '24 at 00:55
One should not use $$ in LaTeX documents. For a longer discussion of this subject, please see the queries Why is \[ ... \] preferable to $$ ... $$? and What are the differences between $$,\[, align, equation and displaymath? The incompatibility of $$ with the fleqn option is noted in the most-upvoted answer to the former query. — Mico, Feb 05 '24 at 01:35

score 5 · Accepted Answer · answered Feb 05 '24 at 01:28

5

Your full document starts with this line:

\documentclass[fleqn,10pt,lineno]{olplainarticle}

The culprit is the document class option fleqn -- short for "flush-left equations". If you want equations to be centered rather than typeset flush-left, get rid of this option.

answered Feb 05 '24 at 01:28

Mico

506,678

1

Or really, get rid of everything and start with an empty document and not a template that doesn't realize that $$ is incompatible with fleqn. – Teepeemm Feb 05 '24 at 01:30
@Teepeemm -- I was willing to give the OP the benefit of the doubt that there might be a valid reason for employing the olplainarticle [!] document class. :-) – Mico Feb 05 '24 at 01:33

Equations are not centered by default on a featured template listed by overleaf

1 Answers1