Source PostScript (coeffmark.pps)

%% syntaxe : (coeff) decomp_coeff -> (num) (den)
/decomp_coeff {
2 dict begin
   /chaine_coeff exch def 
   47 chaine_coeff in {
      %% coeff non entier
      /pivot exch def
      chaine_coeff 0 pivot getinterval 
      chaine_coeff pivot 1 add chaine_coeff length pivot 1 add sub getinterval 
   } {
      %% coeff entier
      chaine_coeff (1)
   } ifelse
end
} def

%% syntaxe : (coeff) (p) p coeff_premark -> ((num * p)/den) coeff*p
/coeff_premark {
5 dict begin
   /valeur exch def
   /symbol exch def
   decomp_coeff
   /chaine_den exch def
   /chaine_num exch def
   chaine_den cvi /den exch def
   chaine_num cvi /num exch def
   den 1 eq {
      %% coeff entier
      chaine_num (1) eqstring {
   	 symbol
      } {
   	 chaine_num (-1) eqstring {
   	    (-) symbol append 
   	 } {
   	    chaine_num symbol append 
   	 } ifelse
      } ifelse
      num valeur mul 
   } {
      %% coeff non entier
      chaine_num (1) eqstring {
   	 symbol (/) append chaine_den append
      } {
   	 chaine_num (-1) eqstring {
   	    (-) symbol append (/) append chaine_den append
   	 } {
   	    chaine_num symbol append (/) append chaine_den append
   	 } ifelse
      } ifelse
      num den div valeur mul 
   } ifelse
end
} def

%% syntaxe : (coeff) p coeff_xtick
/coeff_xtick {
   (p) exch
   coeff_premark xtick pop
} def

%% syntaxe : [(coeff1) (coeff2) ... (coeffn)] p coeff_xticks
/coeff_xticks {
2 dict begin
   /valeur exch def
   {(p) valeur coeff_premark xtick pop} apply
end
} def

%% syntaxe : (coeff) (p) p coeff_xmark
/coeff_xmark {
   coeff_premark dup xtick Oy xmarkstyle
} def

%% syntaxe : [(coeff1) (coeff2) ... (coeffn)] (p) p coeff_xmarks
/coeff_xmarks {
2 dict begin
   /valeur exch def
   /symbol exch def
   {symbol valeur coeff_premark dup xtick Oy xmarkstyle} apply
end
} def

%% syntaxe : (coeff) p coeff_ytick
/coeff_ytick {
   (p) exch
   coeff_premark ytick pop
} def

%% syntaxe : [(coeff1) (coeff2) ... (coeffn)] p coeff_yticks
/coeff_yticks {
2 dict begin
   /valeur exch def
   {(p) valeur coeff_premark ytick pop} apply
end
} def

%% syntaxe : (coeff) (p) p coeff_ymark
/coeff_ymark {
   coeff_premark dup ytick Ox exch ymarkstyle
} def

%% syntaxe : [(coeff1) (coeff2) ... (coeffn)] (p) p coeff_ymarks
/coeff_ymarks {
2 dict begin
   /valeur exch def
   /symbol exch def
   {symbol valeur coeff_premark dup ytick Ox exch ymarkstyle} apply
end
} def