# 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. –  tohecz 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.]

\documentclass{article}
\usepackage{scalerel}

\newcommand\reallywidehat[1]{%
\begin{array}{c}
\stretchto{
\scaleto{
\scalerel*[\widthof{#1}]{\bigwedge}
{\rule[-\textheight/2]{1ex}{\textheight}} %WIDTH-LIMITED BIG WEDGE
}{1.25\textheight} % THIS STRETCHES THE WEDGE A LITTLE EXTRA WIDE
}{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}

$\reallywidehat{zbcdefghijklm}$

$\reallywidehat{zbcdefghijk}$

$\reallywidehat{zbcdefghi}$

$\reallywidehat{zbcdefg}$

$\reallywidehat{zbcde}$

$\reallywidehat{zbc}$

$\reallywidehat{zb}$

\end{document}


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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}
$\widehat{abcdefghijklmnopqrstuvwxyz}$