Graphics, Figures & Tables ⇒ User-defined environment

[ge0rge04]

Hi all.

I tried to create a new environment for this matrix(array)

Code: Select all

\[
  F(x)=\left(\negthickspace
  \begin{array}{cc}
  \\[-6pt]
  \dfrac{x}{2} & 0 \\[6pt]
  0 & x^2\\[2pt]
  \end{array}\negthickspace\right)
\]

the code that initializes the matrix with some values

Code: Select all

\begin{document}
\begin{matrice}
\item 1st
\item 2nd
\item 3rd
\item 4th
\end{matrice}
\end{document}

I'm having a little trouble writing the code for the environment.
From a working example i figured out that it should be something like

Code: Select all

\newenvironment{matrice}{
% the first codebox copy-pasted here
}

and for the second argument i just tried to copy-paste the first code.
pdflatex reports errors at the \item lines.

How do i relate the 1st,2nd...variables to the environment defined ?
Thanks.

[gmedina]

Hi,

dependending on your intent you could also use a command with four arguments. Something along these lines:

Code: Select all

\documentclass{article}
\usepackage{amsmath}

\newcommand\mymatrix[4]{
  \ensuremath{%
  F(x)=\left(\negthickspace
  \begin{array}{cc}
  \\[-6pt]
  #1 & #2 \\[6pt]
  #3 & #4\\[2pt]
  \end{array}\negthickspace\right)
  }
}

\begin{document}

\mymatrix{\dfrac{x}{2}}{0}{0}{x\sp{2}}

\end{document}

[ge0rge04]

hi again
your example was fine, but my task clearly specifies to use \newenvironment only
what should i change in this case?

[ge0rge04]

i solved it
i'll paste the code, maybe someone will find it usefull

Code: Select all

\documentclass{report}
\usepackage{amsmath}
\newenvironment{matrice}[4]{
  
  $$
  F(x)=\left(\negthickspace
  \begin{array}{cc}
  \\[-6pt]
  #1 & #2 \\[6pt]
  #3 & #4\\[2pt]
  \end{array}\negthickspace\right)
  $$
}

\begin{document}

%\begin{matrice}{\displaystyle \frac{x}{2}}{0}{0}{x\sp{2}}
\begin{matrice}{\dfrac{x}{2}}{0}{0}{x\sp{2}}
\end{matrice}
\end{document}

[localghost]

Introducing a displayed math environment with $$…$$ is no good idea (see l2tabu).