I need to write something like {\widetilde f}' in my text, but the result looks rather ugly since the prime (derivative) sign is too low. It looks like \widetilde{f'}.
Is there any way to do this properly?
[Tex/LaTex] Widetilde and prime (derivative) position
amsmathmath-modevertical alignment
Related Solutions
See the mathtools package, which offers the macro \coloneqq for this purpose.
\documentclass{standalone}
\usepackage{mathtools}
\begin{document}
\( b := 10 \) \emph{versus} \( b \coloneqq 10 \).
\end{document}
yields
Click image or right here to see it at full size (1600×133).
Note that the colon is slightly too low on the left, but vertically centered on the right.
You can put {\raisebox{2pt}{$\scriptstyle-$}} in the subscript. You may need to play with \mathchoice if you want a solution that will work in subsubscripts as well.
Edit: Or better yet, \mathpalette:
\makeatletter
\newcommand{\raisemath}[1]{\mathpalette{\raisem@th{#1}}}
\newcommand{\raisem@th}[3]{\raisebox{#1}{$#2#3$}}
\makeatother
and use $\Pi_{\raisemath{2pt}{-}}$.
Best Answer
I'd avoid
\widetilde, particularly above an “f”. A decoration (math accent) above a symbol is usually interpreted as a modifier of the symbol itself, sowill be interpreted as “the derivative of f tilde”, rather than “tilde of the derivative of f”.
Should you feel that an ambiguity could arise, it's probably better to add parentheses
rather than raising the prime that could be mistaken for some “tilde prime”.
Below I show some examples.
As you see, raising the prime is not the answer.