# How to make the this brace bigger? “}”

here is my code:

\begin{equation*}
\left .
\substack{
2 \beta_{r,j}^{(l)} = \beta_{r,j}^{l-1} + \beta_{R+r,j}^{(l-1)} \epsilon_{m}^{j}
\\
2 \beta_{r,m+j}^{(l)} = \beta_{r,j}^{l-1} + \beta_{R+r,j}^{(l-1)} \epsilon_{m}^{j}
}
\right \}
\begin{array}{l l l}
r=0,\dots,R-1
\\
j=0,\dots,m-1
\\
\epsilon_m = e^{\frac{-2 \pi i}{2^m}}
\end{array}
\end{equation*}

it gives me this output:

$\left . \substack{ 2 \beta_{r,j}^{(l)} = \beta_{r,j}^{l-1} + \beta_{R+r,j}^{(l-1)} \epsilon_{m}^{j} \\ 2 \beta_{r,m+j}^{(l)} = \beta_{r,j}^{l-1} + \beta_{R+r,j}^{(l-1)} \epsilon_{m}^{j} } \right \} \begin{array}{l l l} r=0,\dots,R-1 \\ j=0,\dots,m-1 \\ \epsilon_m = e^{\frac{-2 \pi i}{2^m}} \end{array}$

i would like to have it bigger, so that i can read the formular very well. How to do this? How to change the size of the brace ?

Thanks.

• You can change the vertical space between two lines using \\[1em] for example. – Sigur Nov 20 '13 at 16:30

I would suggested aligned (or gathered) for the two blocks on either side of the brace. In any case you can use a rule of zero width to give a minimum size to the brace. In the following the brace size has been made unnaturally large for demonstration purposes.

\documentclass{article}

\usepackage{amsmath}

\begin{document}

\begin{equation*}
\left .
\begin{aligned}
2 \beta_{r,j}^{(l)} &= \beta_{r,j}^{l-1} + \beta_{R+r,j}^{(l-1)}
\epsilon_{m}^{j}
\\[1ex]
2 \beta_{r,m+j}^{(l)} &= \beta_{r,j}^{l-1} +
\beta_{R+r,j}^{(l-1)} \epsilon_{m}^{j}
\end{aligned}
\quad \vrule width 0pt height 7ex \right \}\quad
\begin{aligned}
&r=0,\dots,R-1 \\
&j=0,\dots,m-1 \\
&\epsilon_m = e^{\frac{-2 \pi i}{2^m}}
\end{aligned}
\end{equation*}

\end{document}
• To make the material in the exponent of the final condition more easily decipherable, I'd be tempted to write e^{-2 \pi i/2^m} instead of e^{\frac{-2 \pi i}{2^m}}. – Mico Nov 20 '13 at 17:10
• @Mico I would rewrite as \exp(-2\pi i/2^m)... – Andrew Swann Nov 20 '13 at 20:00
• Even better... :-) – Mico Nov 20 '13 at 20:01

You can use array for LHS also. And the vertical distance can be changed by \\[<dimen>].

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{equation*}
\left .
\begin{array}{r}
2 \beta_{r,j}^{(l)} = \beta_{r,j}^{l-1} + \beta_{R+r,j}^{(l-1)} \epsilon_{m}^{j}
\\[10pt]
2 \beta_{r,m+j}^{(l)} = \beta_{r,j}^{l-1} + \beta_{R+r,j}^{(l-1)} \epsilon_{m}^{j}
\end{array}
\right \}
\begin{array}{l}
r=0,\dots,R-1
\\
j=0,\dots,m-1
\\
\epsilon_m = e^{\frac{-2 \pi i}{2^m}}
\end{array}
\end{equation*}
\end{document}

• @karlkoeller Oh yes. I was about to go to bed, and didn't see RHS at all. Thanks and corrected. :-) – user11232 Nov 20 '13 at 22:08