[Tex/LaTex] Numbering equations with letter and number

equationslabelsnumbering

I need all the equations in one of the sections to be numbered as letter (R) and an ascending number (1, 2, 3…). So they look like (R1), (R2), (R3) etc.

I do not want the number of the section/subsection to appear (not like R3.1.1, R3.1.2, R3.2.1 …) but just an ascending number starting from the beginning of the section, for all the rest of the sections I am satisfied with LaTeX default numbering.

Numbering these equations manually is not an option because while I am writing my paper I often change the order of the equations or add/remove equations from the text.

Best Answer

\section{whatever}
\renewcommand\theequation{R\arabic{equation}}
\setcounter{equation}{0}

should do what you want.

Related Solutions

[Tex/LaTex] Smartly omit chapter number in equation numbering

You can make the prefix conditional on the current chapter being different to the saved chapter in the reference, something like

\documentclass{book}


\renewcommand\theequation{\maybe{\arabic{chapter}}\arabic{section}.\arabic{equation}}
\renewcommand\thechapter{\Roman{chapter}}


\DeclareRobustCommand\maybe[1]{\ifnum#1=\value{chapter}\relax\else\thechapter.\fi}

\usepackage{amsmath}
\begin{document}
\chapter{zz}

\section{lll}

\begin{equation}1=0\label{x}\end{equation}

\section{sss}

\begin{equation}1=-1\label{y}\end{equation}

[[[\ref{x}]]]

\chapter{YY}

[[[\ref{x}]]]

\end{document}

[Tex/LaTex] problem in numbering equations using \numberwithin{equation}{subsection}

Here are two ways of doing things, with the help of the changcntr package. First, if you do not want to display 0for non-existent subsections — i.e. if there is no subsection at one point, display only the section number+the equation number:

\documentclass[11pt,a4paper]{article}

\usepackage[utf8]{inputenc}
\usepackage{amsmath,amsfonts,amssymb}
\usepackage{chngcntr}
\usepackage{etoolbox}
\counterwithin*{equation}{section}
\counterwithin*{equation}{subsection}
\renewcommand\theequation{\ifnumgreater{\value{subsection}}{0}{\thesubsection.}{\thesection.}\arabic{equation}}%

\begin{document}

\section{A First Section}
\begin{equation}
a = b
\end{equation}
\begin{equation}
a + c = b + c
\end{equation}
\begin{equation}
a × c = b × c
\end{equation}

\section{A Second Section}
\begin{equation}
a = b
\end{equation}
\begin{equation}
a + c = b + c
\end{equation}

\section{A Third Section}

An extra equation :
\begin{equation}\
  \ln a = \ln b
\end{equation}
\subsection{First subsection}
\begin{equation}
a = b
\end{equation}
\begin{equation}
a + c = b + c
\end{equation}

\subsection{Second subsection}
\begin{equation}
a = b
\end{equation}
\begin{equation}
a + c = b + c
\end{equation}

\end{document}

enter image description here

If you want the 0 to be displayed, remove from the preamble \renewcommand\theequation{…} and \usepackage{etoolbox}, and replace counterwithin*{equation}{subsection} with the non-starred version.

enter image description here

Best Answer

Related Solutions

[Tex/LaTex] Smartly omit chapter number in equation numbering

[Tex/LaTex] problem in numbering equations using \numberwithin{equation}{subsection}

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