\bar vs. \overline

Another quick post, this time about math. In particular about the \bar option. As many Latex users are aware, the \bar option is used to put a line over a letter/number in math mode, usually representing a mean. The problem with this method is that it puts a fixed-width bar over the letter (I think it's an underscore character '_') instead of covering the width of the letter(s).

This can be easily overcome with the overline option.

overline: \overline
usage: \overline{test}
Explanation: The overline option should be used instead of bar option.

The following code demonstrates the difference

\documentclass[12pt]{beamer}
\mode{
\usetheme{Boadilla}
}
\begin{document}
\begin{frame}[plain]
\begin{alertblock}{WRONG}
\begin{align*}
Z& = \frac{\bar{BMI}-\mu}{\sqrt{\frac{\sigma^2}{N}}} \\
& = \frac{\bar{BMI}-\mu}{SE(\bar{BMI})} \\
\end{align*}
\end{alertblock}
\begin{exampleblock}{RIGHT}
\begin{align*}
Z& = \frac{\overline{BMI}-\mu}{\sqrt{\frac{\sigma^2}{N}}} \\
& = \frac{\overline{BMI}-\mu}{SE(\overline{BMI})} \\
\end{align*}
\end{exampleblock}
\end{frame}
\end{document}

Which produces the following slide