How to make page number footer in the right

Question

I have a class that contains a descrption of frontmatter and backmatter

You can consult the class by following this link.

How I can put the page number right in the footer, knowing that I tried to change the 'LE' and 'RO' indices, but it doesn't work. In the document, when I use \frontmatter and \backmatter, the page number style becomes roman, and I don't know why.

Answer 1

Instead of fancyhdr, you can use \pagestyle{plain} and

\makeatletter
\def\ps@plain{%
      \let\@oddhead\@empty
      \let\@evenhead\@empty
      \def\@oddfoot{\normalfont\hfil\thepage}%
      \def\@evenfoot{\normalfont\hfil\thepage}}
\makeatother

Answer 2

If you want page numbers on the right of the pages use

\cfoot{}
\fancyfoot[RE]{\thepage}
\fancyfoot[RO]{\thepage}

and if you want to make the front and back matter use arabic numbers then just toggle \pagenumbering as shown:

\documentclass[a4paper,20pt]{book}
\usepackage{fancyhdr}
\usepackage{lipsum}

\usepackage{etoolbox}
\patchcmd{\chapter}{plain}{empty}{}{}
\patchcmd{\part}{plain}{empty}{}{}

\cfoot{}
\fancyfoot[RE]{\thepage}
\fancyfoot[RO]{\thepage}

\begin{document}
\pagestyle{fancy}
\frontmatter
\pagenumbering{arabic}
\chapter{Some figures}
\section{Some section}
\lipsum[1-10]
\mainmatter
\chapter{Some figures}
\section{Some section}
\lipsum[1-10]
\backmatter
\pagenumbering{arabic}
\chapter{Some figures}
\section{Some section}
\lipsum[1-10]
\end{document}