% version = 1.08 of naturefem.sty 2003 Mar 6
% 2003 Mar  6, 1.08: corrected comments
% 2003 Jan  2, 1.07: neutral mechanism introduced
% 2002 Dec 12, 1.06: origin

% footnote exchange mechanism in LaTeX for Nature

% This mechanism converts the order given by LaTeX
% to the one desired by Nature at:
% http://www.nature.com/nature/submit/gta/index.html

%   Dr. Thomas D. Schneider
%   National Cancer Institute
%   Laboratory of Experimental and Computational Biology
%   Frederick, Maryland  21702-1201
%   toms@ncifcrf.gov
%   permanent email: toms@alum.mit.edu (use only if first address fails)
%   http://www.lecb.ncifcrf.gov/~toms/

% footnote exchange mechanism
% Lamport p. 195 and p. 196 gives a great example.
% Guide 190, esp

% To keep the calls but to neutralize them, use:
% \newcommand{\ftnexchange}[1]{#1}
% or
% \renewcommand{\ftnexchange}[1]{#1}
% if this file has already defined the function.

% needed for doing if-then tests
\usepackage{ifthen}

% set up the counters
\newcounter{bubbainput}
\newcounter{bubbaresult}
% \newboolean{bubbadouble} % this fails!!!!  A KNOWN LaTeX bug since 1996!!
\newcounter{bubbadouble}
\newcounter{bubbaloop}
\newcounter{ca}
\newcounter{cb}

% This is a little test function as an example of computation.
% call this using: \bubbasum{4}{3}%
\newcommand{\bubbasum}[2]{%
Bubba says that sum(#1, #2) = %
\setcounter{ca}{#1}%
\setcounter{cb}{#2}%
\setcounter{bubbainput}{\value{ca}}%
\addtocounter{bubbainput}{\value{cb}}%
\arabic{bubbainput}
and in Rome as they say,
\Roman{bubbainput}, %
and in footnotation:
\fnsymbol{ca}+%
\fnsymbol{cb}=%
\fnsymbol{bubbainput}.%
  \ifthenelse{\value{ca} = 3}{ca is 3}{ca is not 3}, %
\ifthenelse{\value{cb} = 3}{cb is 3}{cb is not 3} %
}

\newcommand{\subtract}[2]{%
% make a subtraction function since LaTeX doesn't
% seem to have one!
\setcounter{ca}{#1}%
\setcounter{cb}{#2}%
subtract result is: %
%\arabic{cb} %
\addtocounter{ca}{-\value{cb}} %
\arabic{ca} %
}

% This is the exchange function.  Call as:
% Paul N. Hengen,$^{\ftnexchange{1},\ftnexchange{2}}$
\newcommand{\ftnexchange}[1]{%
\setcounter{bubbainput}{#1}%
%(\arabic{bubbainput}% unearth this comment to see the result
% compute if we should double the symbol
\ifthenelse{\value{bubbainput} > 14} %
  {\textbf{The ftnexchange cannot handle more than 14 footnotes! %
   You gave it \arabic{bubbainput}.} %
  }%
  {%
   \setcounter{bubbaresult}{\value{bubbainput}}%
   \ifthenelse{\value{bubbainput} > 7} %
     {%
       \setcounter{bubbadouble}{2}
       \addtocounter{bubbaresult}{-7} % subtract 7
     }%
     {%
       \setcounter{bubbadouble}{1}
     }%
   \ifthenelse{\value{bubbainput}=5}{\setcounter{bubbaresult}{6}}{}%
   \ifthenelse{\value{bubbainput}=6}{\setcounter{bubbaresult}{5}}{}%
   \ifthenelse{\value{bubbainput}=6}{\setcounter{bubbaresult}{5}}{}%
%
   \whiledo {\value{bubbadouble} > 0 } {%
     \ifthenelse{\value{bubbaresult}=7} %
     {\#}%
     {\fnsymbol{bubbaresult}}%
     \addtocounter{bubbadouble}{-1}% subtract 1
   }%
%
  }%
%)% unearth this comment to see the result as "(1*)"
}

\newcommand{\ftnexchangetest}{
% test the ftnexchange
\setcounter{ca}{1}%
\par %
Test of the ftnexchange function in naturefem.sty \\ %
\noindent %
\whiledo {\value{ca} < 16} {%
  \arabic{ca} %
  \ftnexchange{\arabic{ca}} \\%
  \addtocounter{ca}{1}%
} %
\par %
}