2

With reference to Can I have a flexible partial derivative macro?, maybe I should just be happy with the cool package and move on. But...

It sure would be nice if one could specify inset/outset and shorten=true/false as options to a specific instance rather than as separate style options. For example: \pderiv[inset][n]{f}{x}, or perhaps \pderiv[n,inset]{f}{x}. Has anyone tried to modify the package to behave like that?

Also, how about the op's request in the original article to be able to display in the form f_{xxy}?

Community
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rogerl
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2 Answers2

2

Here is what I use to write total and partial derivates. 

% Sources : 
%    * http://forum.mathematex.net/latex-f6/en-tete-de-ds-t12933.html#p124908
%    * http://forum.mathematex.net/latex-f6/derivee-avec-un-d-droit-et-espace-t12932.html#p124930
%    * http://forum.mathematex.net/latex-f6/remplacer-des-espaces-par-autre-chose-t12952.html#p125062
%    * http://forum.mathematex.net/latex-f6/probleme-de-remplacement-de-cdots-t13047.html#p125782

\documentclass[a4paper,10pt]{article}
    \usepackage{amsmath}
    \usepackage{amssymb}

    \usepackage{xstring}
    \noexpandarg % This is necessary so as to  '' \derFrac[3]{\cos}{x} ''  works.


% Power writing of total derivate
    \newcommand{\derPow}[2]{
        #2^{\left( #1 \right)}
    }

% Fractional writing of total derivate
    \DeclareRobustCommand{\dder}{
        \mathop{}\mathopen{}\mathrm{d}
    }

    \newcommand{\dd}[2][0]{
        \IfStrEq{#1}{0}{
            \dder #2
        }{
            \IfBeginWith{#2}{f}{
                \dder^{#1} \! #2
            }{
                \dder^{#1}  #2
            }
        }
    }

    \newcommand{\derFrac}[3][0]{
        \IfStrEq{#1}{0}{
            \ensuremath{\frac{\dd{#2}}{\dd{#3}}}
        }{
            \ensuremath{\frac{\dd[#1]{#2}}{\dd{#3}^{#1}}}
        }
    }

% Subscript writing of partial derivate
    \makeatletter
        \let\original@partial\partial
        \renewcommand{\partial}{
            \original@partial\mathopen{}
        }
    \makeatother

    \newcommand\addPar[1]{(#1)}

    \newcommand\partialSub[2]{
        \def\indPartial{\StrSubstitute{#2}{^}{\addPar}} % This works because xstring traits {...} like a single character.
        \ensuremath{\partial_{\indPartial} #1}
    }

% Prime writing of partial derivate
    \newcommand\partialPrime[2]{
        \def\indPartial{\StrSubstitute{#2}{^}{\addPar}} % This works because xstring traits {...} like a single character.
        \ensuremath{#1^{\prime}_{\indPartial}}
    }

% Fractional writing of partial derivate
    \newcommand{\pp}[2][0]{
        \IfStrEq{#1}{0}{
            \partial #2
        }{
            \IfBeginWith{#2}{f}{
                \partial^{#1} \! #2
            }{
                \partial^{#1} #2
            }
        }
    }

    \newcommand\partialFrac[3][0]{%
        \frac{\partial\IfStrEq{#1}0{}{^{#1}}#2}
        {%
            \StrSubstitute{\partial#3}{ }\partial[\temp]%
            \expandafter\StrSubstitute\expandafter{\temp}{\partial\cdots}{\,\cdots{}\,\partial}
        }
    }

\begin{document}
    \setlength{\parindent}{0pt}
    \newcommand{\HH}{
        \mathrm{H}
    }

    \section{Total derivate}

    $ \cos'(x) =  \derFrac{\cos}{x} (x) $


    $ f'(x) =  \derFrac{f}{x} (x)$


    $ \derPow{5}{\HH} (x) =  \derFrac[5]{\HH}{x} (x) $


    $ \derPow{n}{G} (x) =  \derFrac[n]{G}{x} (x) $


    $ f'''(x) = \derFrac[3]{f}{x} (x) $


    $ \cos'''(x) = \derFrac[3]{\cos}{x} (x) $


    \section{Partial derivate}

    $ \partialPrime{\cos}{x} (x) = \partialFrac{\cos}{x} (x) $


    $ \partialPrime{f}{x} (x) = \partialFrac{f}{x} (x) $


    $ \partialPrime{\HH}{x} (x) = \partialFrac{\HH}{x} (x) $


    $ \partialPrime{f}{x^r y^s} (x,y) = \partialFrac[r + s]{f}{x^r y^s} (x,y) $


    $ \partialPrime{f}{x^{5 + 2} y^{4} z} = \partialFrac[13]{f}{x^{5 + 2} y^{4} z} (x,y) $


    $ \partialSub{G}{f^{5^2} h^4 r} (x,y) = \partialFrac[30]{G}{f^{5^2} h^4 r} (x,y) $


    $ \partialSub{F}{x^n \cdots z^r} (x,\ldots,y) = \partialFrac[N + \cdots + r]{F}{x^n \cdots z^r} (x,\ldots,y) $

\end{document}

enter image description here

Stefan Kottwitz
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projetmbc
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1

Here is a modification of my answer to get a choice key: \pder{f}{x} or \pder{f}{*{2}{x},y}} will choose automatically between display mode or inline mode; in the former case we'll get

\frac{\partial f}{\partial x}
\frac{\partial^{3} f}{\partial x^{2}\partial y}

and in the latter

f_{x}
f_{xxy}

One can also say \pder[display]{f}{...} to get the fraction form or \pder[inline]{f}{...} for the subscript form.

\documentclass[a4paper]{article} 
\usepackage{xkeyval}

\makeatletter 
\define@choicekey{pder}{style}[\der@val\der@nr]{auto,display,inline}{%
  \ifcase\der@nr
    \let\pder@do\pder@choose
  \or
    \let\pder@do\pder@display
  \or
    \let\pder@do\pder@inline
  \fi}
\newcommand\pder[1][auto]{\setkeys{pder}{style=#1}\pder@do}
\def\pder@choose#1#2{%
  \mathchoice{\pder@display{#1}{#2}}{\pder@inline{#1}{#2}}
    {\pder@inline{#1}{#2}}{\pder@inline{#1}{#2}}}
\newcommand{\pder@display}[2]{\begingroup 
  \@tempswafalse\toks@={}\count@=\z@ 
  \@for\next:=#2\do 
    {\expandafter\check@var\next 
     \advance\count@\der@exp 
     \if@tempswa 
       \toks@=\expandafter{\the\toks@\,}% 
     \else 
       \@tempswatrue 
     \fi 
     \toks@=\expandafter{\the\expandafter\toks@\expandafter\partial\der@var}}% 
  \frac{\partial\ifnum\count@=\@ne\else^{\number\count@}\fi#1}{\the\toks@}% 
  \endgroup} 
\def\check@var{\@ifstar{\mult@var}{\one@var}} 
\def\mult@var#1#2{\def\der@var{#2^{#1}}\def\der@exp{#1}} 
\def\one@var#1{\def\der@var{#1}\chardef\der@exp\@ne} 
\newcommand{\pder@inline}[2]{\begingroup 
  \toks@={}%
  \@for\next:=#2\do 
    {\expandafter\check@varinline\next 
     \toks@=\expandafter{\the\expandafter\toks@\der@varinline}}% 
  #1_{\the\toks@}% 
  \endgroup} 
\def\check@varinline{\@ifstar\mult@varinline\one@varinline} 
\def\one@varinline#1{\def\der@varinline{#1}}
\def\mult@varinline#1#2{%
  \def\der@varinline{}\count@\z@ % initialize
  \loop\ifnum\count@<#1\relax
    \expandafter\def\expandafter\der@varinline\expandafter{%
      \der@varinline#2}%
    \advance\count@\@ne
 \repeat} 
\makeatother 

\begin{document}
\[
\pder{f}{x}\qquad \pder{f}{*{2}{x},y}\qquad \pder[inline]{f}{*{3}{x},y,*{4}{z}} 
\]

$
\pder{f}{x}\qquad \pder{f}{*{2}{x},y}\qquad \pder[display]{f}{*{3}{x},y,*{4}{z}} 
$
\end{document}
egreg
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