# Resize brackets for publication?

I am unsure how to select appropriate size of brackets for different equations.

Example

$$(v, \frac{\partial^{2} u}{\partial t^{2}}) + c^{2}(\nabla v, \nabla u) - c^{2} (v, \frac{\partial u}{\partial n})_{\partial \Omega} = (f,v).$$


output

Example 2

$$\Big(v, \frac{\partial^{2} u}{\partial t^{2}}\Big) + c^{2}(\nabla v, \nabla u) - c^{2} \Big(v, \frac{\partial u}{\partial n}\Big)_{\partial \Omega} = (f,v).$$


output

I think the last example is the best one because the brackets are as high as the inner thing. Is there any way to automatise the resizing of brackets for publication format?

• Perhaps you want to use \left( and \right)? – Niel de Beaudrap Nov 8 '13 at 12:18
• What do you mean by “publication format”? Either the typesetting is good or it is bad. – egreg Nov 8 '13 at 12:18
• \left( and \right) are usually to big. Your second example is fine if you replace \Big( by \Bigl( and \Big) by \Bigr) I think. – pluton Nov 8 '13 at 12:20
• @pluton \left and \right only make delimiters as big as you ask. If you do not like the default size then you should change \delimtershortfall and \delimiterfactor – David Carlisle Nov 8 '13 at 12:23

Your input seem to mean that you're using a kind of scalar product. In this case it's recommended to define your own command for it.

You can solve the “inner product” problem with mathtools; also a macro for partial derivatives should be defined.

\documentclass{article}
\usepackage{mathtools}
\DeclarePairedDelimiterX{\inprod}[2]{(}{)}{#1,#2}
\newcommand{\pder}[3][]{%
\frac{\partial^{#1}#2}{\partial#3^{#1}}%
}

\begin{document}
$$\inprod[\Big]{v}{\pder[2]{u}{t}} + c^{2}\inprod{\nabla v}{\nabla u} - c^{2} \inprod[\Big]{v}{\pder{u}{n}}_{\partial \Omega} = (f,v).$$
$$\inprod*{v}{\pder[2]{u}{t}} + c^{2}\inprod{\nabla v}{\nabla u} - c^{2} \inprod*{v}{\pder{u}{n}}_{\partial \Omega} = (f,v).$$
\end{document}


Now you're free to add the size of the delimiter as optional argument to \inprod; with \inprod* you choose automatic sizing, which should be done with care and only when necessary. Be consistent.