%D \module
%D   [       file=m-graph,
%D        version=2008.09.08,
%D          title=\CONTEXT\ Extra Modules,
%D       subtitle=\METAPOST\ graph module support,
%D         author=Hans Hagen,
%D           date=\currentdate,
%D      copyright={PRAGMA ADE \& \CONTEXT\ Development Team}]
%C
%C This module is part of the \CONTEXT\ macro||package and is
%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
%C details.

% We just assume lua specification instead of the graph ones that
% are limited by what mp can do. We support @ as replacement for
% the percent symbol. We also add a specifier when no one is given.

\startluacode
    local format, gsub, find, match = string.format, string.gsub, string.find, string.match

    local simplify = true

    local function strip(n,e)
        -- get rid of e(0)
        -- get rid of e(+*)
        e = gsub(e,"^+","")
        -- remove leading zeros
        e = gsub(e,"^([+-]*)0+(%d)","%1%2")
        if not simplify then
            -- take it as it is
        elseif n == "1" then
            return format("10^{%s}",e)
        end
        return format("%s\\times10^{%s}",n,e)
    end

    function metapost.format_n(fmt,str)
        fmt = gsub(fmt,"@","%%")
        local initial, hasformat, final = match(fmt,"^(.-)(%%.-[%a])(.-)$")
        if hasformat then
            str = format(fmt,str)
            str = gsub(str,"(.-)e(.-)$",strip)
            str = format("%s\\mathematics{%s}%s",initial,str,final)
        elseif not find(fmt,"%%") then
            str = format("%"..fmt,str)
            str = gsub(str,"(.-)e(.-)$",strip)
            str = format("\\mathematics{%s}",str)
        end
        context(str)
    end
\stopluacode

\unexpanded\def\MPgraphformat#1#2{\ctxlua{metapost.format_n("#1","#2")}}

% We could also delegate parsing using lower level plugins.

\startMPextensions
    if unknown Fe_plus : picture Fe_plus ; Fe_plus := textext("+") ; fi ;
    if unknown context_grap: input "mp-grap.mpiv" ; fi ;
\stopMPextensions

\continueifinputfile{m-graph.mkiv}

\starttext

\startMPpage
    label(format("@g","1e-8"),  (0,       0)) ;
    label(format("@g","1e+8"),  (2cm,     0)) ;
    label(format("@g","1e-10"), (0,  -0.5cm)) ;
    label(format("@g","1e+10"), (2cm,-0.5cm)) ;
    label(format("@g","1e-12"), (0,  -1.0cm)) ;
    label(format("@g","1e+12"), (2cm,-1.0cm)) ;
    label(format("@g","1e-0"),  (0,  -1.5cm)) ;
    label(format("@g","1e+0"),  (2cm,-1.5cm)) ;
    label(format("@g","1"),     (0,  -2.0cm)) ;
    label(format("@g","1"),     (2cm,-2.0cm)) ;
    label(format("@g","1e-102"),(0,  -2.5cm)) ;
    label(format("@g","1e+102"),(2cm,-2.5cm)) ;
\stopMPpage

% \startMPpage
% draw begingraph(3in,2in);
%     gdraw "t:/metapost/grphdata/agepop91.d";
% endgraph;
% \stopMPpage

% \startMPpage
% draw begingraph(3in,2in);
%     gdraw "agepop91.d" plot btex $\bullet$ etex;
% endgraph;
% \stopMPpage

% \startMPpage
% draw begingraph(3in,2in);
%     glabel.lft(btex \vbox{\hbox{Population} \hbox{in millions}} etex, OUT);
%     glabel.bot(btex Age in years etex, OUT);
%     gdraw "agepopm.d";
% endgraph;
% \stopMPpage

% \startMPpage
% draw begingraph(3in,2in);
%     glabel.lft(btex \vbox{\hbox{Population} \hbox{in millions}} etex, OUT);
%     glabel.bot(btex Age in years etex, OUT);
%     setrange(origin, whatever,whatever);
%     gdraw "agepopm.d";
% endgraph;
% \stopMPpage

% \startMPpage
% draw begingraph(2.3in,2in);
%     setcoords(log,log);
%     glabel.lft(btex Seconds etex,OUT);
%     glabel.bot(btex Matrix size etex,
%     OUT);
%     gdraw "matmul.d" dashed evenly;
%     glabel.ulft(btex Standard etex,8);
%     gdraw "matmul.d";
%     glabel.lrt(btex Strassen etex,7);
% endgraph;
% \stopMPpage

% \startMPpage
% draw begingraph(6.5cm,4.5cm);
%     setrange(80,0, 90,whatever);
%     glabel.bot(btex Year etex, OUT);
%     glabel.lft(btex \vbox{\hbox{Emissions in} \hbox{thousands of}
%     \hbox{metric tons} \hbox{(heavy line)}}etex, OUT);
%     gdraw "lead.d" withpen pencircle scaled 1.5pt;
%     autogrid(,otick.lft);
%     setcoords(linear,linear);
%     setrange(80,0, 90,whatever);
%     glabel.rt(btex \vbox{\hbox{Micrograms} \hbox{per cubic}
%     \hbox{meter of air} \hbox{(thin line)}}etex, OUT);
%     gdraw "lead.d";
%     autogrid(otick.bot,otick.rt);
% endgraph;
% \stopMPpage

\stoptext