Math & Science ⇒ Large Arrow on top of Symbol

[marcdein]

How can I display a large arrow on top of a symbol? I need something like \vec, but with a longer arrow which extends over a longer symbol. For example, $\vec X_+$ only displays the arrow on top of the X, but I need it to extend over the whole symbol $X_+$.

[Frits]

Try the following:

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\documentclass{article}
\renewcommand{\vec}[1]{\overrightarrow{#1}}
\begin{document}
$\vec{xy}$
\end{document}

For the standard LaTeX font (Computer Modern), this solution isn't very neat (as shown in this post).

[marcdein]

Thanks, but isn't there a way to display an arrow that looks more like the one you get with \vec?

[Frits]

As far as I know, there is no symbol like that. Also note that the arrow over symbols is used mainly for handwritten vectors. In literature, you mostly find vectors to be bold. Consider this then:

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\renewcommand{\vec}[1]{\ensuremath{\boldsymbol{#1}}}

[maxmax]

I've had the same problem some time ago.

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\vec{e_x}

looks bad because the arrow is too small. Now i use

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\vec{e}_x

which looks much better.

But clearly this isn't suitable if the arrow has to be extended over the whole term.