Page Layout ⇒ Change section number to lettering

[LeonardH]

How do I change the default section numbering to the format below? I am using Miktex console 2.9 and Texmaker.

I. Section
a. Subsection
b. Subsection
i. Subsubsection
ii. subsubsection

I have tried searching and don't find exactly what I need. I am so new at Latex that I probably don't know what to search for.

[Ijon Tichy]

A good solution would depend on the class you are using and several other design decisions, e.g., how references to section, subsection and subsubsection should be. A very simple solution for the standard class article (but usually not for the KOMA-Script class scrartcl) would be:

\documentclass{article}

\renewcommand*{\thesection}{\Roman{section}.}
\renewcommand*{\thesubsection}{\arabic{subsection}.}
\renewcommand*{\thesubsubsection}{\roman{subsubsection}.}

\begin{document}

\section{Section}
\subsection{Subsection}
\subsection{Subsection}
\subsubsection{Subsubsection}
\subsubsection{subsubsection}

\end{document}

[LeonardH]

Perfect. That got me in the right direction. Saved me a lot of time.

I did change the arabic in: \renewcommand*{\thesubsection}{\arabic{subsection}.}

to alph: \renewcommand*{\thesubsection}{\alph{subsection}.}

to get letters instead of numbers.