amsmathsuperscripts
I have a function in my .sty sheet that does a second partial derivative:
\newcommand{\hpartdsq}[2]{\dfrac{\partial^2 #1}{\partial #2 ^2}}
But I'd like to pass it something that already has a superscript (today it's \rho^*).
Is there a way to do this with this function? I feel like wrapping the \rho^* with parentheses would really kill the aesthetics and is not typical for second partial derivatives. Thanks!
The construct \vphantom is not a math operator, thus the rules for an ordinary math atom applies for the superscript. \mathop helps:
\documentclass{article}
\begin{document}
\[
\int^S = \mathop{\vphantom{\int}}\nolimits^S
\]
\[
\int\limits^S = \mathop{\vphantom{\int}}^S
\]
\end{document}
With package amsmath an "empty" math operator can be declared with \DeclareMathOperator:
\documentclass{article}
\usepackage{amsmath}
\DeclareMathOperator*{\vint}{\vphantom{\int}}
\begin{document}
\[
\int^S = \vint\nolimits^S
\]
\[
\int\limits^S = \vint^S
\]
\end{document}
In case of a larger closing delimiter, \mathclose can help, e.g.:
\documentclass{article}
\begin{document}
\[
\Biggr)^S = \mathclose{\vphantom{\Biggr)}}^S
\]
\end{document}
I do not know, the reason for the question. If only a lonely higher superscript is needed, then an invisible \rule or \raisebox will help:
\documentclass{article}
\begin{document}
\[
{}^S < \rule{0pt}{2.5ex}^S < \raisebox{3ex}{$\scriptstyle S$}
\]
\end{document}
This is the easiest way:
\documentclass{article}
\usepackage{amsmath}
\newcommand{\wbigcup}{\mathop{\widetilde{\bigcup}}\displaylimits}
\begin{document}
\[
\wbigcup_{i=1}^n A_i
\]
\end{document}
Note that \displaylimits is not really needed, but clarity is important.
Best Answer
One cheap solution is to call the macro like this:
\hpartdsq{f}{{\rho^*}}.EDIT: Maybe I should add that it's not a good idea to modify the macro definition so that it contains the braces
{}: If you call this macrowith
\hpartdsq{f}{\rho^*}, then it looks as desired, but with\hpartdsq{f}{x_1}the^2will be too far to the right.