Take the 2-minute tour ×
TeX - LaTeX Stack Exchange is a question and answer site for users of TeX, LaTeX, ConTeXt, and related typesetting systems. It's 100% free, no registration required.

How to create a new counter of equation. The new equation is matriz and use other sequence number.

\documentclass[a4paper,10pt]{article}
\usepackage[utf8]{inputenc}

\begin{document}

\begin{equation}
 y = x
\end{equation}

\begin{equation}
 y = \frac{1}{x}
\end{equation}

The of next matriz equation is 1.

\begin{matriz}
y = \sqrt x
\end{matriz}

\end{document}

I need, equation 1 equation 2 matriz 1 matriz 2 equation 3 matriz 3 matriz 4

New counter of matriz.

share|improve this question

2 Answers 2

up vote 7 down vote accepted

This can be done using a newenvironment and the amsmath to help with the tagging

screenshot

I have defined the matriz environment in terms of the equation environment, and tagged it with a new counter; you can use \label and \eqref as usual.

\documentclass{article}
\usepackage{amsmath}

\newcounter{matriz}
\newenvironment{matriz}{\refstepcounter{matriz}\equation}{\tag{M\thematriz}\endequation}
\begin{document}

\begin{equation}
 y = x
\end{equation}

\begin{equation}
 y = \frac{1}{x}
\end{equation}

The of next matriz equation is 1. \eqref{test}
\begin{matriz}\label{test}
y = \sqrt x
\end{matriz}

\end{document}
share|improve this answer

amsmath with more than equation

I'd go a broader approach …

The following codes uses the environment m and its mandatory argument to use any amsmath environment (that introduces displayed math-mode) in combination with the matrix counter.

The etoolbox helps to redefine the macros \print@eqnum and \incr@eqnum. An alternative is given in the commented part of the code.

Without cmhughes’ solution the actual equation environment still uses \print@eqnum with \theequation but \incr@eqnum with matrix.

Code

\documentclass[a4paper,10pt]{article}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{etoolbox}

\newcounter{matrix}
\renewcommand*{\thematrix}{M\arabic{matrix}}

\makeatletter
\def\@equationname{equation}
\newenvironment{m}[1]{%
    \def\mymathenvironmenttouse{#1}%
    \ifx\mymathenvironmenttouse\@equationname%
        \refstepcounter{matrix}%
    \else
        \patchcmd{\@arrayparboxrestore}{equation}{matrix}{}{}%          doesn't change output?
        \patchcmd{\print@eqnum}{equation}{matrix}{}{}%
        \patchcmd{\incr@eqnum}{equation}{matrix}{}{}%
%       \def\print@eqnum{\tagform@\thematrix}%                          instead of etoolbox' \pathcmd
%       \def\incr@eqnum{\refstepcounter{matrix}\let\incr@eqnum\@empty}% instead of etoolbox' \pathcmd
    \fi
    \csname\mymathenvironmenttouse\endcsname%
}{%
    \ifx\mymathenvironmenttouse\@equationname%
        \tag{\thematrix}%
    \fi
    \csname end\mymathenvironmenttouse\endcsname%
}
\makeatother
\begin{document}

\begin{equation}
 y = x
\end{equation}

\begin{equation}
 y = \frac{1}{x}
\end{equation}

The of next matriz equation is \ref{eq:M1}.
\begin{m}{equation}
 y = \sqrt x \label{eq:M1}
\end{m}

\begin{equation}
 y = \frac{1}{x}
\end{equation}

\begin{m}{align}
 y & = \sqrt x \\
 z & = y^2
\end{m}

\begin{m}{alignat}{3}
 y & = \sqrt x & \quad\text{col2l} & = \text{col2r} & \quad\text{col3l} & = \text{col3r} \\
 z & = y^2 & & & &
\end{m}

\begin{m}{equation}
 y = \sqrt x
\end{m}
\end{document}

Output

enter image description here

Sans-amsmath solution (without eqnarray)

Code

\documentclass[a4paper,10pt]{article}
\usepackage[utf8]{inputenc}

\newcounter{matrix}
\renewcommand*{\thematrix}{M\arabic{matrix}}

\makeatletter
\newenvironment{matriz}{%
    \def\@eqnnum{{\normalfont \normalcolor (\thematrix)}}%
    \def\equation{$$\refstepcounter{matrix}}%
    \equation%
}{%
    \endequation%
}
\makeatother

\begin{document}

\begin{equation}
 y = x
\end{equation}

\begin{equation}
 y = \frac{1}{x}
\end{equation}

The of next matriz equation is \ref{eq:m1}.

\begin{matriz}\label{eq:m1}
y = \sqrt x
\end{matriz}

\begin{equation}
 y = x
\end{equation}

\begin{matriz}
y = \sqrt x
\end{matriz}
\end{document}

Output

enter image description here

share|improve this answer
    
+1 very nice and general! –  yo' Nov 26 '12 at 12:29

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.