[Tex/LaTex] Error using subequations

equationsnumberingsubequations

I am using subequations. There is no way to get a right output…
I am using

\documentclass{book}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{amsfonts}
\usepackage{amsthm}

\begin{document}

\begin{subequations}
\begin{equation}%<-----------------------<
h\nu'=\frac{h\nu}{1+\gamma(1-\cos\theta)}
\end{equation}
\begin{equation}
T=h\nu-h\nu'=h\nu \frac{\gamma(1-\cos\theta)}{1+\gamma(1-\cos\theta)}
\end{equation}
\begin{equation}
\cos\theta=1-\frac{2}{(1+\gamma)^2\tan^2\phi+1}
\end{equation}
\begin{equation}
\cot\phi=(1+\gamma)\tan\frac{\theta}{2}
\end{equation}
\end{subequations}

\end{document}

I also used $some equations$ and \[some equations\] instead of equation enviroment but I can't get numbering…
Any ideas?

P.S.: The error occurs on line marked with arrow in aforementioned code which states: extra \else
Missing \endcsname inserted
Incomplete \iffalse; all text wasignored after line67.

\documentclass[11pt,a4paper]{book}
\usepackage[english,greek]{babel}
\usepackage[iso-8859-7]{inputenc}
\usepackage{kerkis}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{amsfonts}
\usepackage{amsthm}
\usepackage{units}
\usepackage{array}
\usepackage{framed} % ãéá ãêñé background ðßóù áðü êÜðïéá paragraphs
\usepackage{extarrows}
\usepackage{cancel}
\usepackage[pdftex]{graphicx}
%\usepackage[twoside,pdftex,total={16.4cm,24cm}, left=2.9cm, top=3.2cm, headsep=1.4cm]    {geometry}
%\usepackage[top=3.2cm, bottom=3.4cm, left=2.9cm, right=2.9cm,headsep=0.8cm]{geometry}
\usepackage[margin=2.8cm]{geometry}
%Options: Sonny, Lenny, Glenn, Conny, Rejne, Bjarne, Bjornstrup
\renewcommand\chaptername{ÊåöÜëáéï}
%\usepackage{babelbib}
%\selectbiblanguage{english}
\renewcommand\bibname{Âéâëéïãñáößá}
\usepackage[Glenn]{fncychap}
\usepackage{fancybox}
\usepackage{fancyhdr}
\usepackage{colortbl}
\usepackage{xcolor}
\usepackage{footmisc}
\usepackage{subfiles}
\usepackage{float}
\usepackage{slashbox}
\usepackage{float}
%\restylefloat{figure}
%_________________________________________________________________________________________

%\usepackage[nottoc,numbib]{tocbibind}
\usepackage{fancyhdr}

%!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
\usepackage{tocloft}
\makeatletter
\newcommand*{\tocwithouttitle}{\@starttoc{toc}}
\makeatother
%--------------------------------------------------------------------------------
\makeatletter
\newcommand*{\lofwithouttitle}{\@starttoc{lof}}
\makeatother
%--------------------------------------------------------------------------------
\makeatletter
\newcommand*{\lotwithouttitle}{\@starttoc{lot}}
\makeatother
%--------------------------------------------------------------------------------
%!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
\renewcommand{\cftsecleader}{\cftdotfill{\cftdotsep}}
\usepackage{hyperref}
\usepackage{subfigure}
\renewcommand{\labelitemi}{$\circ$}
\usepackage{wrapfig}
\usepackage{color}
%\usepackage[usenames,dvipsnames]{color}
\definecolor{Darkgreen}{rgb}{0,0.4,0}
\definecolor{Darkblue}{rgb}{0,0,0.4}
\newcommand{\HRule}{\rule{\linewidth}{0.8mm}}
\usepackage{rotating}
%\usepackage[landscape]{geometry}
\usepackage{lscape}
\usepackage{cancel}
\usepackage{fancyvrb}
%\usepackage{yannisgr}
\usepackage{listings}
%\lstset{ %
%language=matlab,                % choose the language of the code
%basicstyle=\footnotesize,       % the size of the fonts that are used for the code
%numbers=left,                   % where to put the line-numbers
%numberstyle=\footnotesize,      % the size of the fonts that are used for the line-    numbers
%stepnumber=1,                   % the step between two line-numbers. If it is 1 each     line will be numbered
%numbersep=5pt,                  % how far the line-numbers are from the code
%backgroundcolor=\color{white},  % choose the background color. You must add     \usepackage{color}
%showspaces=false,               % show spaces adding particular underscores
%showstringspaces=false,         % underline spaces within strings
%showtabs=false,                 % show tabs within strings adding particular     underscores
%frame=single,           % adds a frame around the code
%tabsize=2,          % sets default tabsize to 2 spaces
%captionpos=b,           % sets the caption-position to bottom
%breaklines=true,        % sets automatic line breaking
%breakatwhitespace=false,    % sets if automatic breaks should only happen at     whitespace
%escapeinside={\%*}{*)}          % if you want to add a comment within your code
%}
\usepackage{textcomp}
\definecolor{listinggray}{gray}{0.9}
\definecolor{lbcolor}{rgb}{0.9,0.9,0.9}
\lstset{
    backgroundcolor=\color{lbcolor},
    tabsize=4,
rulecolor=,
language=matlab,
    basicstyle=\scriptsize,
    upquote=true,
    aboveskip={1.5\baselineskip},
    columns=fixed,
    showstringspaces=false,
    extendedchars=true,
    breaklines=true,
    prebreak = \raisebox{0ex}[0ex][0ex]{\ensuremath{\hookleftarrow}},
    frame=single,
    showtabs=false,
    showspaces=false,
    showstringspaces=false,
    identifierstyle=\ttfamily,
    keywordstyle=\color[rgb]{0,0,1},
    commentstyle=\color[rgb]{0.133,0.545,0.133},
    stringstyle=\color[rgb]{0.627,0.126,0.941},
}
\usepackage{pifont}
\usepackage{subfiles}

%_________________________________________________________________________________________


\definecolor{mygray}{gray}{.75}%{.9, .9, .9}
\definecolor{lightgray}{gray}{.8}%{.9, .9, .9}
\definecolor{shadecolor}{gray}{.90} %gia framed package
%\definecolor{mygray}{rgb}{.9, .9, .9} %enallaktika !! anti gia panw
\newcommand*\mygraybox[1]{\colorbox{mygray}{\hspace{1em}#1\hspace{1em}}}

%\renewcommand{\topfraction}{0.85}%gia na min uparxoun 2 figures se mia selida kai     tipota allo
\renewcommand{\textfraction}{0.1}
\renewcommand{\floatpagefraction}{0.75}

\newcommand{\kai}{\quad \text{êáé} \quad}
\newcommand{\kkai}{\qquad \text{êáé} \qquad}

\linespread{1.1}
\newcommand{\sw}{\selectlanguage{english}}
\newcommand{\sq}{\selectlanguage{greek}}
\newcommand{\eng}[1]{\latintext#1\greektext}
\newcommand{\gre}[1]{\greektext\latintext#1}
\newcolumntype{C}[1]{>{\centering\let\newline\\\arraybackslash\hspace{0pt}}m{#1}}

\begin{comment}   %ÁõôÜ ãéá âéâëßï
\let\origdoublepage\cleardoublepage  %áõôá åéíáé ãéá íá áöçíåé åíôåëùò êåíç óåëéäá     ìåôáîõ êåöáëáéùí
\newcommand{\clearemptydoublepage}{%
  \clearpage
  {\pagestyle{empty}\origdoublepage}%
}
\let\cleardoublepage\clearemptydoublepage


\pagestyle{fancy}
\fancyhead{}
\renewcommand{\chaptermark}[1]{\markboth{#1}{}}
\renewcommand{\sectionmark}[1]{\markright{\thesection\ #1}}
\fancyhf{} % delete current setting for header and footer
\fancyhead[LE,RO]{\bfseries\thepage}
\fancyhead[LO]{\rightmark}
\fancyhead[RE]{\leftmark}
\renewcommand{\headrulewidth}{0.5pt}
\renewcommand{\footrulewidth}{0pt}
\addtolength{\headheight}{0.5pt} % make space for the rule      %Ôï ÷ù ïñßóåé 0.8 áð ôï     package
\fancypagestyle{plain}%
\fancyhead{} % get rid of headers on plain pages
\renewcommand{\headrulewidth}{0pt} % and the line}

\newtheorem{thm}{Èåþñçìá}[chapter]
\newtheorem{cor}[thm]{Ðüñéóìá}
\newtheorem{lem}[thm]{ËÞììá}
\newtheorem{parad}{ÐáñÜäåéãìá}[chapter]
\newtheorem{defgr}{Ïñéóìüò}[chapter]
\end{comment}

\parskip 3mm
\footskip = 15mm
%``````````````````````````````````````````````````````````````````
%--\texorpdfstring{$\textswab{BoSonS}$}{Bosons}--
%``````````````````````````````````````````````````````````````````

Best Answer

I did not found any error from your given code.

But you can try this one:

\documentclass{book}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{amsfonts}
\usepackage{amsthm}

\begin{document}
\renewcommand{\theequation}{1\alph{equation}}
\setcounter{equation}{0}

%\begin{subequations}
\begin{equation}%<-----------------------<
h\nu'=\frac{h\nu}{1+\gamma(1-\cos\theta)}
\end{equation}
\begin{equation}
T=h\nu-h\nu'=h\nu \frac{\gamma(1-\cos\theta)}{1+\gamma(1-\cos\theta)}
\end{equation}
\begin{equation}
\cos\theta=1-\frac{2}{(1+\gamma)^2\tan^2\phi+1}
\end{equation}
\begin{equation}
\cot\phi=(1+\gamma)\tan\frac{\theta}{2}
\end{equation}
%\end{subequations}


\end{document}

Related Solutions

[Tex/LaTex] Customizing subequations numbering in itemized list

You can introduce a new counter mysub

\newcounter{mysub}
\setcounter{mysub}{0}
\renewcommand{\themysub}{def\arabic{mysub}}

and use this one instead of \theequation inside the subequations.

If you also want this counter to be reset after the end of the subequations, also add the following lines

\usepackage{etoolbox}
\AtEndEnvironment{subequations}{\setcounter{mysub}{0}}

MWE:

\documentclass[10pt]{article}

% for fancy math
\usepackage{amsmath}

% rank operator
\DeclareMathOperator*{\rank}{rank}

% Matrix transpose
\newcommand{\trans}[1]{\ensuremath{{#1}^\top}}

% for extra space at the end of abbreviation
\usepackage{xspace}

% positive semi-definite
\newcommand{\psd}{\textsc{psd}\xspace}

% boldface uppercase letters for matrices
\newcommand{\Abf}{\ensuremath{\mathbf A}}
\newcommand{\Bbf}{\ensuremath{\mathbf B}}

% boldface lowercase letters for vectors
\newcommand{\xbf}{\ensuremath{\mathbf x}}

% for math blackboard font
\usepackage{amssymb}
% set of real numbers
\newcommand{\Rbb}{\ensuremath{\mathbb R}}

\usepackage{palatino}
\usepackage[sc]{mathpazo}

\usepackage{etoolbox}
\AtEndEnvironment{subequations}{\setcounter{mysub}{0}}

\newcounter{mysub}
\setcounter{mysub}{0}
\renewcommand{\themysub}{def\arabic{mysub}}

\begin{document}
\noindent
For any real symmetric matrcies $\Abf$ such that $\rank(\Abf_{n\times n})=r$,
the following statements are equivalent
and any one of them can serve as the definition of
\emph{positive semi-definite} (\psd) matrices.
\begin{subequations}\label{eq:1}
\begin{itemize}
  \item $\trans\xbf \Abf\xbf \geq 0$ for any non-zero vector
    $\xbf\in\Rbb^{n\times 1}$.
    \hfill\refstepcounter{mysub}\textup{(\themysub)}\label{eq:1a}%
  \item All the $n$ eigenvalues of $\Abf$ are non-negative.
    \hfill\refstepcounter{mysub}\textup{(\themysub)}%
  \item $\Abf=\trans\Bbf \Bbf$ for some $\Bbf$ with $\rank(\Bbf)=r$.
    \hfill\refstepcounter{mysub}\textup{(\themysub)}%
\end{itemize}
\end{subequations}

\noindent
We refer to the global equation \eqref{eq:1} and to subequation \eqref{eq:1a}

\end{document}

Output:

enter image description here

[Tex/LaTex] numbering parentequation of subequations

I'd define a new environment, to which you give the desired label as argument.

\documentclass{article}
\usepackage{amsmath}

\makeatletter
\newenvironment{varsubequations}[1]
 {%
  \addtocounter{equation}{-1}%
  \begin{subequations}
  \renewcommand{\theparentequation}{#1}%
  \def\@currentlabel{#1}%
 }
 {%
  \end{subequations}\ignorespacesafterend
 }
\makeatother

\begin{document}
An equation
\begin{equation}
1=1
\end{equation}
Some subequations
\begin{varsubequations}{P1}
\label{eq:Parent}
  \begin{align}
  a& \label{eq:1}\\
  b& \label{eq:2}
  \end{align}
\end{varsubequations}
Another equation
\begin{equation}
2=2
\end{equation}
Now the references: \eqref{eq:Parent}, \eqref{eq:1}, \eqref{eq:2}.
\end{document}

enter image description here

Best Answer

Related Solutions

[Tex/LaTex] Customizing subequations numbering in itemized list

[Tex/LaTex] numbering parentequation of subequations

Related Question