# Really wide hat symbol

Is there any way to get a hat wider than widehat?

Why doesn't

\widehat{abcdefghijklmnopqrstuvwxyz}


really go over all of it?

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Wouldn't you prefer $(abcdefgh)^{\wedge}$? – Benjamin McKay Mar 2 '13 at 14:51
– percusse Mar 2 '13 at 14:53
@hmmmm Yes, exactly! I'm not sure what you want it for, I'm sure that the result won't be nice, no matter how much you try. Putting the whole thing in parenthesis, and the symbol as an exponent in the very end is quite a common way to do that (e.g. with open sets, word reversals etc.). IMHO \wedge is not the best option, and $(abcdefg)\widehat{\phantom{x}}$ would do a better job, but that it a matter of choice. – yo' Mar 2 '13 at 15:18
@hmmmm Yes, a little wedge at the end. As a mathematician, I would prefer Fourier transforms or series written with a hat or wedge (or check) at the end of the expression, if the expression is long, because otherwise the symbol looks too big to me. – Benjamin McKay Mar 2 '13 at 15:55
You can also write \mathcal{F}(f) for the Fourier transform of f; this is how I'd do it for longer expressions. – Hendrik Vogt Mar 3 '13 at 15:52

The question wasn't "should it be done?" But, for the same reason men climb mountains, "could it be done?" The answer, with the scalerel package, is yes. Thus, we introduce \reallywidehat [EDITED to add phantom rule below argument, so that baseline of result matches baseline of original argument. RE-EDITED to \ensuremath on the \widthof calculation (thanks to Thruston)]

NEW ANSWER WITH stackengine

This answer is an improvement because it handles vertical space much better than the earlier solution.

\documentclass{article}
\usepackage{scalerel,stackengine}
\stackMath
\newcommand\reallywidehat[1]{%
\savestack{\tmpbox}{\stretchto{%
\scaleto{%
\scalerel*[\widthof{\ensuremath{#1}}]{\kern-.6pt\bigwedge\kern-.6pt}%
{\rule[-\textheight/2]{1ex}{\textheight}}%WIDTH-LIMITED BIG WEDGE
}{\textheight}%
}{0.5ex}}%
\stackon[1pt]{#1}{\tmpbox}%
}
\parskip 1ex
\begin{document}

$\reallywidehat{zbcdefghijklm}$

$\reallywidehat{zbcdefghijk}$

$\reallywidehat{zbcdefghi}$

$\reallywidehat{zbcdefg}$

$\reallywidehat{zbcde}$

$\reallywidehat{zbc}$

$\reallywidehat{zb}$

$x\cdot\reallywidehat{a_1+a_2}\cdot y$

\end{document}


EARLIER ANSWER WITH array

\documentclass{article}
\usepackage{scalerel}

\newcommand\reallywidehat[1]{\arraycolsep=0pt\relax%
\begin{array}{c}
\stretchto{
\scaleto{
\scalerel*[\widthof{\ensuremath{#1}}]{\kern-.5pt\bigwedge\kern-.5pt}
{\rule[-\textheight/2]{1ex}{\textheight}} %WIDTH-LIMITED BIG WEDGE
}{\textheight} %
}{0.5ex}\\           % THIS SQUEEZES THE WEDGE TO 0.5ex HEIGHT
#1\\                 % THIS STACKS THE WEDGE ATOP THE ARGUMENT
\rule{-1ex}{0ex}
\end{array}
}

\begin{document}

$\reallywidehat{zbcdefghijklm}$

$\reallywidehat{zbcdefghijk}$

$\reallywidehat{zbcdefghi}$

$\reallywidehat{zbcdefg}$

$\reallywidehat{zbcde}$

$\reallywidehat{zbc}$

$\reallywidehat{zb}$

$x\cdot\reallywidehat{a_1+a_2}\cdot y$

\end{document}


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You want an \ensuremath{} inside your \widthof{} call... otherwise it fails if the argument to reallywidehat contains any real maths. For example try it with \reallywidehat{a_1+a_2}. – Thruston Apr 14 '15 at 20:38
@Thruston Thank you for the correction. – Steven B. Segletes Apr 14 '15 at 23:02

While echoing the sentiment expressed in the earlier answer -- "this stuff really shouldn't be encouraged" -- I can't resist pointing out that \widehat can easily be made super-wide with the help of the mtpro2 (MathTime Professional II) package. Note that this package isn't free of charge and can't be downloaded from the CTAN. However, its "lite" subset -- which is all that's needed to create superwide "widehat" accents -- is free of charge and may be downloaded from this site.

\documentclass{article}
\usepackage[lite]{mtpro2}
\begin{document}
$\widehat{abcdefghijklmnopqrstuvwxyz}$
\end{document}

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how to install the font? – user19832 Feb 23 '14 at 14:51
@user19832 - Have you followed the instructions provided at pctex.com/mtpro2.html? – Mico Feb 23 '14 at 15:57

I tried some of these except the {mtpro2} since for submitting articles that might not be acceptable by publishers!

As I was not satisfied by the previous methods mentioned above, I tried to tailor another method, you can apply the following code, play with the scale factors and positions and choose which one you prefer. The last two I recommend but I myself prefer the last, which I am going to use myself:

\documentclass{article}

\usepackage{amsmath}
\usepackage{amssymb}
\usepackage[ngerman]{babel}
\usepackage{stackengine}
\usepackage{scalerel}

\begin{document}

$\widehat{ABCDEF}$

$\stackon[0pt]{ABCDEF}{\hstretch{7.0}{\wedge}}$

$\stackon[-8pt]{ABCDEF}{\vstretch{1.5}{\hstretch{9.0}{\widehat{\phantom{\;}}}}}$

$\stackon[-8pt]{ABCDEF}{\vstretch{1.5}{\hstretch{2.4}{\widehat{\phantom{\;\;\;\;\;\;\;\;}}}}}$

\end{document}


The result would be something like this:

Have fun

Ehsan Tavakoli

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