3

I'm trying to fit this matrix within one column. But it is exceeding the limit and overlapping with the column beside of it.

\documentclass{IEEEtran}
\usepackage{amsmath}

\begin{document}
$e^{At}$ = \[ \left[ \begin{array}{ccc}
3*e^{-t}-3*e^{-2t}+e^{-3t} & \dfrac{5}{2}*e^{-t}-4*e^{-2t}+\dfrac{3}{2}*e^{-3t} & \dfrac{1}{2}*e^{-t}-e^{-2t}+\dfrac{1}{2}*e^{-3t} \\\\
-3*e^{-t}+6*e^{-2t}-3*e^{-3t} & \dfrac{-5}{2}*e^{-t}+8*e^{-2t}-\dfrac{9}{2}*e^{-3t} & \dfrac{-1}{2}*e^{-t}+2*e^{-2t}-\dfrac{3}{2}*e^{-3t} \\\\
3*e^{-t}-12*e^{-2t}+9*e^{-3t} & \dfrac{5}{2}*e^{-t}-16*e^{-2t}+\dfrac{27}{2}*e^{-3t} & \dfrac{1}{2}*e^{-t}-4*e^{-2t}+\dfrac{9}{2})*e^{-3t} \end{array} \right]\]
\end{document}
7
  • Do you really need * to denote multiplication?
    – Sigur
    Commented Sep 5, 2015 at 18:01
  • No...not at all Commented Sep 5, 2015 at 18:02
  • You can delete all of them and also use only \begin{bmatrix}\end{bmatrix}. Also, use \\[1em] to change line instead of insert blank lines.
    – Sigur
    Commented Sep 5, 2015 at 18:04
  • 1
    Welcome to TeX.sx!
    – strpeter
    Commented Sep 5, 2015 at 18:05
  • 1
    You can always switch to a temporary smaller font {\small ... } or \small...\normalsize. Commented Sep 5, 2015 at 18:33

3 Answers 3

1

I suggest you use the cuted package, and its strip environment, so as the equation spreads over two columns. I also reduced the size of the fraction coefficients using the \mfrac command (medium sized fractions), from the nccmath package:

\documentclass{ieeeconf}
\usepackage[utf8]{inputenc}
\usepackage{lipsum}
\usepackage{mathtools, nccmath}
\usepackage{cuted}
\input{insbox.tex}

\begin{document}
\lipsum[1]
\setlength\stripsep{\partopsep}%

\begin{strip}
  \[
    e^{At}=
    \begin{bmatrix}
      3 e^{-t}-3 e^{-2t}+e^{-3t} & \mfrac{5}{2} e^{-t}-4 e^{-2t}+\mfrac{3}{2} e^{-3t} & \mfrac{1}{2} e^{-t}-e^{-2t}+\mfrac{1}{2} e^{-3t} \\[2ex]
      -3 e^{-t}+6 e^{-2t}-3 e^{-3t} & -\mfrac{5}{2} e^{-t}+8 e^{-2t}-\mfrac{9}{2} e^{-3t} & -\mfrac{1}{2} e^{-t}+2 e^{-2t}-\mfrac{3}{2} e^{-3t} \\[2ex]
      3 e^{-t}-12 e^{-2t}+9 e^{-3t} & \mfrac{5}{2} e^{-t}-16 e^{-2t}+\mfrac{27}{2} e^{-3t} & \mfrac{1}{2} e^{-t}-4 e^{-2t}+\mfrac{9}{2} e^{-3t}
    \end{bmatrix}
  \]
\end{strip}
\lipsum[3-6]

\end{document} 

enter image description here

1

enter image description here

\documentclass[conference,twocolumn]{IEEEtran}
\usepackage{amsmath,lipsum}
\begin{document}

\begin{figure*}[!t]
\normalsize
\begin{equation}
e^{At}=\left[
\begin{array}{ccc}
3e^{-t}-3e^{-2t}+e^{-3t} & \dfrac{5}{2}e^{-t}-4e^{-2t}+\dfrac{3}{2}e^{-3t} & \dfrac{1}{2}e^{-t}-e^{-2t}+\dfrac{1}{2}e^{-3t} \\[1em]
-3e^{-t}+6e^{-2t}-3e^{-3t} & \dfrac{-5}{2}e^{-t}+8e^{-2t}-\dfrac{9}{2}e^{-3t} & \dfrac{-1}{2}e^{-t}+2e^{-2t}-\dfrac{3}{2}e^{-3t} \\[1em]
3e^{-t}-12e^{-2t}+9e^{-3t} & \dfrac{5}{2}e^{-t}-16e^{-2t}+\dfrac{27}{2}e^{-3t} & \dfrac{1}{2}e^{-t}-4e^{-2t}+\dfrac{9}{2}e^{-3t} 
\end{array}\right]
\end{equation}
\hrulefill
\vspace*{4pt}
\end{figure*}

\lipsum[1-10]

\begin{align}
&e^{At}=\notag\\ 
&\begin{bmatrix}
   3 \alpha-3 \beta+\gamma    & \dfrac{5}{2} \alpha-4 \beta+\dfrac{3}{2} \gamma & \dfrac{1}{2} \alpha-\beta+\dfrac{1}{2} \gamma \\[1em]
  -3 \alpha+6 \beta-3 \gamma  & \dfrac{-5}{2} \alpha+8 \beta-\dfrac{9}{2} \gamma & \dfrac{-1}{2} \alpha+2 \beta-\dfrac{3}{2} \gamma \\[1em]
   3 \alpha-12 \beta+9 \gamma & \dfrac{5}{2} \alpha-16 \beta+\dfrac{27}{2} \gamma & \dfrac{1}{2} \alpha-4 \beta+\dfrac{9}{2} \gamma
\end{bmatrix}
\end{align}    
where $\alpha=e^{-t}$, $\beta=e^{-2t}$, and $\gamma=e^{-3t}$.

\lipsum[11-15]
\end{document}

You can always substitute the large symbols or partial expressions with shorter ones. In this case, assuming \alpha, \beta, and \gamma are not used before, you can replace e^{-t}, e^{-2t}, and e^{-3t} by the shorter \alpha, \beta, and \gamma, respectively.

The second approach is to place the equation at the top of the next page followed by an \hrulefill. In this case, the equation will span the two columns. Also, you should introduce the equation some how earlier to let it appear in the right place. The equation is wrapped into a figure* environment with choosing the [!t] specifier for LaTeX to try very hard to place the equation at the top of the next page.

See Page 8 of How to Use the IEEEtran LATEX Class for more details.

1
  • I like this easy solution, but there will be some issues if the equation is on the 2nd column, it will appear on next page at top.
    – AlFagera
    Commented Oct 10, 2020 at 13:56
0

I suggest you group the terms e{-t}, e^{-2t}, and e^{-3t} into a column vector named, say, \tilde{e}. This will let you write the matrix as follows (the horizontal lines in the screenshot are there just to illustrated with width of the columns):

enter image description here

Of course, if you can assume that your readers are familiar with matrix algebra notation, this new expression may be written still more compactly...

\documentclass{IEEEtran}
\usepackage{mathtools}
\newcommand\evec{\tilde{e}}  % choose suitable vector notation
\begin{document}
\hrule % just to demonstrate column width

\bigskip
Set $\evec=\begin{bmatrix}e^{-t} & e^{-2t} & e^{-3t} \end{bmatrix}'$. Then $e^{At}$ is given by
\[ 
\begin{bmatrix*}[r]
\begin{bmatrix} 3 & -3 & 1 \end{bmatrix}\evec & 
\begin{bmatrix} \frac{5}{2} & -4 & \frac{3}{2} \end{bmatrix}\evec &
\begin{bmatrix} \frac{1}{2} & -1 & \frac{1}{2}\end{bmatrix}\evec \, \\[2ex]
\begin{bmatrix} -3 & 6 & -3 \end{bmatrix}\evec & 
\begin{bmatrix} \frac{-5}{2} & 8 & \frac{-9}{2} \end{bmatrix}\evec &
\begin{bmatrix} \frac{-1}{2} & 2 & \frac{-3}{2} \end{bmatrix}\evec \, \\[2ex]
\begin{bmatrix} 3 & -12 & 9 \end{bmatrix}\evec &
\begin{bmatrix} \frac{5}{2} & -16& \frac{27}{2}\end{bmatrix}\evec &
\begin{bmatrix} \frac{1}{2}& -4& \frac{9}{2} \end{bmatrix}\evec \,
\end{bmatrix*} 
\]

\hrule % just to demonstrate column width
\end{document} 

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