How do I change the subsection by Roman letter to number in Lyx?

Question

I am using one IEEE template to write one two column paper, after converted into pdf format, the subsection is identified with Roman letters, such as I, II, III, IV, etc. I want to change it to numbers like: 1, 2, 3, 4, etc.

How can I do that?

Answer 1

Indeed, the IEEEtran class defaults to upper case Roman numerals for sections and upper case letters for subsections, and adding \renewcommand{\thesubsection}{\thesection.\arabic{subsection}} seems to have no effect.

However, there is a [compsoc] class option that is intended to mimic the format of the IEEE Computer Society's publications, and one those adjustments that is made with this is that Arabic numerals are used exclusively for sections and subsections. So the following MWE produces the desired results:

\documentclass[compsoc]{IEEEtran}
\begin{document}
\section{Section One}
\subsection{First Subsection}
\end{document}

There are other things that this option effects so is best to refer to the package documentation.

Answer 2

The IEEEtran class numbers sections with Roman numbers and subsections with letters.

So the correct remedy is

\renewcommand{\thesection}{\arabic{section}}