How to get an upright \partial?

Question

I want to set partial derivations like \frac{\partial}{\partial x}. This is issue is discussed several times here. Packages like esdiff or commath or suggested. However one problem with all those solutions is that the \partial is not set upright. Usually a recommendation is to use kpfonts or other fonts. Assume I do not want to change my font. Is there some LaTeX command to set the \partial upright or is this always a font issue? I have tried using \mathrm, but this doesn't work.

Answer 1

\usepackage[partialup]{kpfonts}

or if you do not want to load the kpfonts:

\documentclass{scrartcl}
\usepackage[T1]{fontenc}
\makeatletter
\newif\ifkp@upRm% is used in the .fd-file of jkp
\DeclareSymbolFont{Letters}{OML}{jkp}{m}{n}
\DeclareMathSymbol{\partialup}{\mathord}{Letters}{128}
\makeatother
\usepackage{mathptmx}

\begin{document}

\[ \frac{\partialup f}{\partialup x} \]

\end{document}