stable 2013.05.18 02:06

1 files changed, 487 insertions, 442 deletions

diff --git a/metapost/context/base/mp-grap.mpiv b/metapost/context/base/mp-grap.mpiv
index 1c7a50124..34b1bd1cc 100644
--- a/metapost/context/base/mp-grap.mpiv
+++ b/metapost/context/base/mp-grap.mpiv
@@ -24,7 +24,7 @@ fi
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
-% $Id: graph.mp,v 1.2 2004/09/19 21:47:10 karl Exp $
+% $Id : graph.mp,v 1.2 2004/09/19 21 :47 :10 karl Exp $
 % Public domain.
 
 % Macros for drawing graphs
@@ -39,10 +39,10 @@ fi
 % glabel<suffix>(pic,loc)        place label pic near graph coords or time loc
 % gdotlabel<suffix>(pic,loc)     same with dot
 % OUT                            loc value for labels relative to whole graph
-% gdata(file,s,text)             read coords from file; evaluate t w/ tokens s[]
+% gdata(file,s,text)             read coords from file ; evaluate t w/ tokens s[]
 % auto.<x or y>                  default x or y tick locations (for interation)
 % itick.<bot|top|..>(fmt,u)      draw inward tick from given side at u w/ format
-% otick.<bot|top|..>(fmt,u)      draw outward tick at coord u; label format fmt
+% otick.<bot|top|..>(fmt,u)      draw outward tick at coord u ; label format fmt
 % grid.<bot|top|..>(fmt,u)       draw grid line at u with given side labeled
 % autogrid([itick|.. bot|..],..) iterate over auto.x, auto.y, drawing tick/grids
 % frame.[bot|top..]              draw frame (or one side of the frame)
@@ -61,9 +61,9 @@ fi
 
 % Other than the above-documented user interface, all externally visible names
 % are of the form X_.<suffix>, Y_.<suffix>, or Z_.<suffix>, or they start
-% with `graph_' (was: "`G' and end with `_'").
+% with `graph_'
 
-% Depends on:
+% Depends on :
 input string.mp
 
 % Private version of a few marith macros, fixed for double math...
@@ -71,106 +71,112 @@ newinternal mzero ;   mzero := -53*mlog 2 ; % Anything at least this small is tr
 newinternal mlogten ; mlogten := mlog(10) ; % Would this be better inline?
 
 % Safely convert a number to mlog form
-vardef graph_mlog primary x = if x=0 : mzero else : mlog(abs x) fi enddef;
+vardef graph_mlog primary x =
+  if unknown x : whatever
+  elseif x=0 :   mzero
+  else :         mlog(abs x)
+  fi
+enddef ;
 
 % Convert x from mlog form into a pair whose xpart gives a mantissa and whose
 % ypart gives a power of ten.
 vardef graph_Meform(expr x) =
-  if x<=mzero: origin
-  else:
-    save e; e=round(x/mlogten)-3;
-    (mexp(x-e*mlogten), e)
+  if x<=mzero : origin
+  else :
+    save e, m ; e=floor(x/mlogten)-3; m := mexp(x-e*mlogten) ;
+    if abs m<1000 : m := m*10 ; e := e-1 ; elseif abs m>=10000 : m := m/10 ; e := e+1 ; fi
+    (m, e)
   fi
-enddef;
+enddef ;
 
 % Modified from above.
 vardef graph_Feform(expr x) =
-  interim warningcheck:=0;
-  if x=0: origin
-  else:
-    save e; e=round(if x<0: -mlog(-x) else: mlog(x) fi/mlogten)-3;
-    (x/(10**e), e)
+  interim warningcheck :=0 ;
+  if x=0 : origin
+  else :
+    save e, m ; e=floor(if x<0 : -mlog(-x) else : mlog(x) fi/mlogten)-3; m := x/(10**e) ;
+    if abs m<1000 : m := m*10 ; e := e-1 ; elseif abs m>=10000 : m := m/10 ; e := e+1 ; fi
+    (m, e)
   fi
-enddef;
+enddef ;
 
 vardef graph_error(expr x,s) =
-  interim showstopping:=0;
-  show x; errmessage s;
-enddef;
+  interim showstopping :=0 ;
+  show x ; errmessage s;
+enddef ;
 
 %%%%%%%%%%%%%%%%%%%%%%%% Data structures, begingraph %%%%%%%%%%%%%%%%%%%%%%%%
 
-vardef Z_@# = (X_@#,Y_@#) enddef; % used in place of plain.mp's z convention
+vardef Z_@# = (X_@#,Y_@#) enddef ; % used in place of plain.mp's z convention
 
 def graph_suffix(suffix $) = % convert from x or y to X_ or Y_
-  if str$="x": X_ else: Y_ fi
-enddef;
+  if str$="x" : X_ else : Y_ fi
+enddef ;
 
-% New:
+% New :
 save graph_background ; color graph_background ; % if defined, fill the frame.
 
 def begingraph(expr w, h) =
   begingroup
-  save X_, Y_;
+  save X_, Y_ ;
   X_.graph_coordinate_type =
-  Y_.graph_coordinate_type = linear; % coordinate system for each axis
-  Z_.graph_dimensions = (w,h);  % dimensions of graph not counting axes etc.
-% Z_.low, Z_.high       user-specified coordinate ranges in units used in graph_current_graph
-
-  save    graph_finished_graph;
-  picture graph_finished_graph; % the finished part of the graph
-          graph_finished_graph  = nullpicture;
-  save    graph_current_graph;
-  picture graph_current_graph;  % what has been drawn in current coords
-          graph_current_graph   = nullpicture;
-  save    graph_current_bb;
-  picture graph_current_bb;     % picture whose bbox is graph_current_graph's w/ linewidths 0
-          graph_current_bb      = nullpicture;
-  save    graph_last_drawn;
-  picture graph_last_drawn;     % result of last gdraw or gfill
-          graph_last_drawn      = nullpicture;
-  save    graph_plot_picture;
-  picture graph_plot_picture;   % a picture from the `plot' option known when plot allowed
-  save    graph_label;
-  picture graph_label[];        % labels to place around the whole graph when it is done
-  save    graph_autogrid_needed;
-  boolean graph_autogrid_needed; % whether autogrid is needed
-          graph_autogrid_needed  = true;
-  save    graph_frame_needed;
-  boolean graph_frame_needed;    % whether frame needs to be drawn
-          graph_frame_needed     = true;
-  save    graph_number_of_arrowheads; % number of arrowheads for next gdraw
-          graph_number_of_arrowheads = 0;
+  Y_.graph_coordinate_type = linear ; % coordinate system for each axis
+  Z_.graph_dimensions = (w,h) ;       % dimensions of graph not counting axes etc.
+  %also, Z_.low, Z_.high  user-specified coordinate ranges in units used in graph_current_graph
+
+  save    graph_finished_graph ;
+  picture graph_finished_graph ; % the finished part of the graph
+          graph_finished_graph  = nullpicture ;
+  save    graph_current_graph ;
+  picture graph_current_graph ;  % what has been drawn in current coords
+          graph_current_graph   = nullpicture ;
+  save    graph_current_bb ;
+  picture graph_current_bb ;     % picture whose bbox is graph_current_graph's w/ linewidths 0
+          graph_current_bb      = nullpicture ;
+  save    graph_last_drawn ;
+  picture graph_last_drawn ;     % result of last gdraw or gfill
+          graph_last_drawn      = nullpicture ;
+  save    graph_plot_picture ;
+  picture graph_plot_picture ;   % a picture from the `plot' option known when plot allowed
+  save    graph_label ;
+  picture graph_label[] ;        % labels to place around the whole graph when it is done
+  save    graph_autogrid_needed ;
+  boolean graph_autogrid_needed ; % whether autogrid is needed
+          graph_autogrid_needed  = true ;
+  save    graph_frame_needed ;
+  boolean graph_frame_needed ;    % whether frame needs to be drawn
+          graph_frame_needed     = true ;
+  save    graph_number_of_arrowheads ; % number of arrowheads for next gdraw
+          graph_number_of_arrowheads = 0 ;
 
   if known graph_background : % new feature!
     fill origin--(w,0)--(w,h)--(0,h)--cycle withcolor graph_background ;
   fi
-enddef;
+enddef ;
 
-% Additional variables not explained above:
+% Additional variables not explained above :
 % graph_modified_lower, graph_modified_higher  pairs giving bounds used in auto<x or y>
-% graph_exponent, graph_comma     variables and macros used in auto<x or y>
-% Gc_                   temporary macro used in auto<x or y> ????
-% graph_modified_bias   an offset to graph_modified_lower and graph_modified_higher to ease computing exponents
+% graph_exponent, graph_comma                  variables and macros used in auto<x or y>
+% graph_modified_bias
+%   an offset to graph_modified_lower and graph_modified_higher to ease computing exponents
 % Some additional variables function as constants.  Most can be modified by the
 % user to alter the behavior of these macros.
-% Not very modifiable:  log, linear,
-%                       graph_frame_pair_a, graph_frame_pair_b, graph_margin_pair
-% Modifiable:           Gtemplate.suffix, Glmarks[], Gumarks, Gemarks, Gmarks,
-%                       Gminlog, Autoform
-
+% Not very modifiable :  log, linear,
+%                        graph_frame_pair_a, graph_frame_pair_b, graph_margin_pair
+% Modifiable :           Gtemplate.suffix, Glmarks[], Gumarks, Gemarks, Gmarks,
+%                        Gminlog, Autoform
 
-newinternal log, linear;        % coordinate system codes
-log:=1; linear:=2;
 
+newinternal log, linear ;        % coordinate system codes
+log :=1 ; linear :=2;
+% note that mp-tool.mpiv defines log as log10...
 
-
-%%%%%%%%%%%%%%%%%%%%%% Coordinates: setcoords, setrange %%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%% Coordinates : setcoords, setrange %%%%%%%%%%%%%%%%%%%%%%
 
 % Graph-related usr input is `user graph coordinates' as specified by arguments
 % to setcoords.
 % `Internal graph coordinates' are used for graph_current_graph, graph_current_bb, Z_.low, Z_.high.
-% Their meaning depends on the appropriate component of Z_.graph_coordinate_type:
+% Their meaning depends on the appropriate component of Z_.graph_coordinate_type :
 %     log means internal graph coords =  mlog(user graph coords)
 %    -log means internal graph coords = -mlog(user graph coords)
 %  linear means internal graph coords =      (user graph coords)
@@ -178,13 +184,14 @@ log:=1; linear:=2;
 
 
 vardef graph_set_default_bounds =         % Set default Z_.low, Z_.high
-  forsuffixes $=low,high:
-    (if known X_$: whatever else: X_$ fi, if known Y_$: whatever else: Y_$ fi)
-        = graph_margin_fraction$[llcorner graph_current_bb,urcorner graph_current_bb] + graph_margin_pair$;
+  forsuffixes $=low,high :
+    (if known X_$ : whatever else : X_$ fi, if known Y_$ : whatever else : Y_$ fi)
+        = graph_margin_fraction$[llcorner graph_current_bb,urcorner graph_current_bb] +
+          graph_margin_pair$ ;
   endfor
-enddef;
-pair graph_margin_pair.low, graph_margin_pair.high;
-graph_margin_pair.high = -graph_margin_pair.low = (.00002,.00002);
+enddef ;
+pair graph_margin_pair.low, graph_margin_pair.high ;
+graph_margin_pair.high = -graph_margin_pair.low = (.00002,.00002) ;
 
 
 % Set $, $$, $$$ so that shifting by $ then transforming by $$ and then $$$
@@ -192,31 +199,31 @@ graph_margin_pair.high = -graph_margin_pair.low = (.00002,.00002);
 % `essential bounding box' is either what Z_.low and Z_.high imply or the
 % result of ignoring pen widths in graph_current_graph.
 vardef graph_remap(suffix $,$$,$$$) =
-  save p_;
-  graph_set_default_bounds;
-  pair p_, $; $=-Z_.low;
-  p_ = (max(X_.high-X_.low,.9), max(Y_.high-Y_.low,.9));
-  transform $$, $$$;
-  forsuffixes #=$$,$$$: xpart#=ypart#=xypart#=yxpart#=0; endfor
-  (Z_.high+$) transformed $$ = p_;
-  p_ transformed $$$ = Z_.graph_dimensions;
-enddef;
-graph_margin_fraction.low=-.07;         % bbox fraction for default range start
-graph_margin_fraction.high=1.07;        % bbox fraction for default range stop
+  save p_ ;
+  graph_set_default_bounds ;
+  pair p_, $ ; $=-Z_.low;
+  p_ = (max(X_.high-X_.low,.9), max(Y_.high-Y_.low,.9)) ;
+  transform $$, $$$ ;
+  forsuffixes #=$$,$$$ : xpart#=ypart#=xypart#=yxpart#=0 ; endfor
+  (Z_.high+$) transformed $$ = p_ ;
+  p_ transformed $$$ = Z_.graph_dimensions ;
+enddef ;
+graph_margin_fraction.low=-.07 ;         % bbox fraction for default range start
+graph_margin_fraction.high=1.07 ;        % bbox fraction for default range stop
 
 
 def graph_with_pen_and_color(expr q) =
   withpen penpart q withcolor
-  if colormodel q=1:
+  if colormodel q=1 :
     false
-  elseif colormodel q=3:
+  elseif colormodel q=3 :
     (greypart q)
-  elseif colormodel q=5:
+  elseif colormodel q=5 :
     (redpart q, greenpart q, bluepart q)
-  elseif colormodel q=7:
+  elseif colormodel q=7 :
     (cyanpart q, magentapart q, yellowpart q, blackpart q)
   fi
-enddef;
+enddef ;
 
 % Add picture component q to picture @# and change part p to tp, where p is
 % something from q that needs coordinate transformation.  The type of p is pair
@@ -224,101 +231,115 @@ enddef;
 % Pair o is the value of p that makes tp (0,0).  This implements the trick
 % whereby using 1 instead of 0 for th the width or height or the setbounds path
 % for a label picture suppresses shifting in x or y.
-vardef old_graph_picture_conversion@#(expr q, o)(text tp) =
-  save p;
-  if stroked q:
-    path p; p=pathpart q;
-    addto @# doublepath tp graph_with_pen_and_color(q) dashed dashpart q;
-  elseif filled q:
-    path p; p=pathpart q;
-    addto @# contour tp graph_with_pen_and_color(q);
-  else:
-    interim truecorners:=0;
-    pair p; p=llcorner q;
-    if urcorner q<>p: p:=p+graph_coordinate_multiplication(o-p,urcorner q-p); fi
-    addto @# also q shifted ((tp)-llcorner q);
-  fi
-enddef;
-% TH: new version from code found at sarovar tracker. This makes 
+%vardef graph_picture_conversion@#(expr q, o)(text tp) =
+%  save p ;
+%  if stroked q :
+%    path p ; p=pathpart q;
+%    addto @# doublepath tp graph_with_pen_and_color(q) dashed dashpart q ;
+%  elseif filled q :
+%    path p ; p=pathpart q;
+%    addto @# contour tp graph_with_pen_and_color(q) ;
+%  else :
+%    interim truecorners :=0 ;
+%    pair p ; p=llcorner q;
+%    if urcorner q<>p : p :=p+graph_coordinate_multiplication(o-p,urcorner q-p) ; fi
+%    addto @# also q shifted ((tp)-llcorner q) ;
+%  fi
+%enddef ;
+% TH : new version from code found at sarovar tracker. This makes 
 %     grdaw clip the result to the window defined with setrange
 vardef graph_picture_conversion@#(expr q, o)(text tp) =
-  save p, tp_geclipt; 
-  picture tp_geclipt; tp_geclipt:=nullpicture;
-  if stroked q:
-    path p; p=pathpart q;
+  save p, tp_geclipt ; 
+  picture tp_geclipt ; tp_geclipt :=nullpicture;
+  if stroked q :
+    path p ; p=pathpart q;
     %%%  --- SDV added
-      addto tp_geclipt doublepath tp graph_with_pen_and_color(q) dashed dashpart q;
-      clip tp_geclipt to origin--(xpart Z_.graph_dimensions,0)--Z_.graph_dimensions--(0, ypart Z_.graph_dimensions)--cycle;
-      addto @# also tp_geclipt;
+      addto tp_geclipt doublepath tp graph_with_pen_and_color(q) dashed dashpart q ;
+      clip tp_geclipt to origin--(xpart Z_.graph_dimensions,0)--Z_.graph_dimensions--(0, ypart Z_.graph_dimensions)--cycle ;
+      addto @# also tp_geclipt ;
     %%%  
     %%%  --- SDV deleted
-    %%addto @# doublepath tp graph_with_pen_and_color(q) dashed dashpart q;
+    %%addto @# doublepath tp graph_with_pen_and_color(q) dashed dashpart q ;
     %%%
-  elseif filled q:
-    path p; p=pathpart q;
-    addto @# contour tp graph_with_pen_and_color(q);
-  else:
-    interim truecorners:=0;
-    pair p; p=llcorner q;
-    if urcorner q<>p: p:=p+graph_coordinate_multiplication(o-p,urcorner q-p); fi
-    addto @# also q shifted ((tp)-llcorner q);
+  elseif filled q :
+    path p ; p=pathpart q;
+    addto @# contour tp graph_with_pen_and_color(q) ;
+  else :
+    interim truecorners :=0 ;
+    pair p ; p=llcorner q;
+    if urcorner q<>p : p :=p+graph_coordinate_multiplication(o-p,urcorner q-p) ; fi
+    addto @# also q shifted ((tp)-llcorner q) ;
   fi
-enddef;
+enddef ;
 
-def graph_coordinate_multiplication(expr a,b) = (xpart a*xpart b, ypart a*ypart b) enddef;
+def graph_coordinate_multiplication(expr a,b) = (xpart a*xpart b, ypart a*ypart b) enddef ;
 
 
-vardef graph_clear_bounds@# =  numeric @#.low, @#.high;  enddef;
+vardef graph_clear_bounds@# =  numeric @#.low, @#.high ;  enddef;
 
 
 % Finalize anything drawn in the present coordinate system and set up a new
 % system as requested
 vardef setcoords(expr tx, ty) =
-  interim warningcheck:=0;
-  if length graph_current_graph>0:
-    save s, S, T;
-    graph_remap(s, S, T);
-    for q within graph_current_graph:
-      graph_picture_conversion.graph_finished_graph(q, -s, p shifted s transformed S transformed T);
+  interim warningcheck :=0 ;
+  if length graph_current_graph>0 :
+    save s, S, T ;
+    graph_remap(s, S, T) ;
+    for q within graph_current_graph :
+      graph_picture_conversion.graph_finished_graph(q,-s,p shifted s transformed S transformed T) ;
     endfor
-    graph_current_graph := graph_current_bb := nullpicture;
+    graph_current_graph := graph_current_bb := nullpicture ;
   fi
-  graph_clear_bounds.X_; graph_clear_bounds.Y_;
-  X_.graph_coordinate_type:=tx; Y_.graph_coordinate_type:=ty;
-enddef;
+  graph_clear_bounds.X_ ; graph_clear_bounds.Y_;
+  X_.graph_coordinate_type := tx ; Y_.graph_coordinate_type := ty;
+enddef ;
 
 
 % Set Z_.low and Z_.high to correspond to given range of user graph
 % coordinates.  The text argument should be a sequence of pairs and/or strings
 % with 4 components in all.
 vardef setrange(text t) =
-  interim warningcheck:=0;
-  save r_; r_=0;
-  string r_[]s;
+  interim warningcheck :=0 ;
+  save r_ ; r_=0;
+  string r_[]s ;
   for x_=
-      for p_=t: if pair p_: xpart p_, ypart fi p_, endfor:
-    r_[incr r_] if string x_: s fi = x_;
-    if r_>2:
-      graph_set_bounds if r_=3: X_ else: Y_ fi(r_[r_-2] if unknown r_[r_-2]: s fi, x_);
+      for p_=t : if pair p_ : xpart p_, ypart fi p_, endfor :
+    r_[incr r_] if string x_ : s fi = x_ ;
+    if r_>2 :
+      graph_set_bounds if r_=3 : X_ else : Y_ fi (r_[r_-2] if unknown r_[r_-2] : s fi, x_) ;
     fi
-    exitif r_=4;
+    exitif r_=4 ;
   endfor
-enddef;
+enddef ;
 
 
-% @# is X_ or Y_; l and h are numeric or string
-% It would not be OK to set (@#low,@#high) to a pair expression because $ might
-% try to rescale @#low when evaluating the right-hand side for @#high.
+% @# is X_ or Y_ ; l and h are numeric or string
 vardef graph_set_bounds@#(expr l, h) =
-  graph_clear_bounds@#;
-  if @#graph_coordinate_type>0:
-     @#low  = if abs @#graph_coordinate_type=log: graph_mlog fi if string l : scantokens fi l;
-     @#high = if abs @#graph_coordinate_type=log: graph_mlog fi if string h : scantokens fi h;
-  else:
-    -@#high = if abs @#graph_coordinate_type=log: graph_mlog fi if string l : scantokens fi l;
-    -@#low  = if abs @#graph_coordinate_type=log: graph_mlog fi if string h : scantokens fi h;
+  graph_clear_bounds@# ;
+  if @#graph_coordinate_type>0 :
+     @#low  = if unknown l :
+                whatever 
+              else :
+                if abs @#graph_coordinate_type=log : graph_mlog fi if string l : scantokens fi l
+              fi ;
+     @#high = if unknown h :
+                whatever
+              else :
+                if abs @#graph_coordinate_type=log : graph_mlog fi if string h : scantokens fi h
+              fi ;
+  else :
+    -@#high = if unknown l : 
+                whatever
+              else :
+                if abs @#graph_coordinate_type=log : graph_mlog fi if string l : scantokens fi l
+              fi ;
+    -@#low  = if unknown h :
+                whatever
+              else :
+                if abs @#graph_coordinate_type=log : graph_mlog fi if string h : scantokens fi h
+              fi ;
   fi
-enddef;
+enddef ;
 
 
 
@@ -330,36 +351,37 @@ enddef;
 % x and y parts of each coordinate pair.  Boolean parameter c tells whether to
 % force the result to be polygonal.
 vardef graph_scan_path(expr p, c)(suffix tx, ty) =
-  if (str tx="") and (str ty=""):  p
-  else:
-    save r_; path r_;
+  if (str tx="") and (str ty="") :  p
+  else :
+    save r_ ; path r_;
     r_ := graph_pair_adjust(point 0 of p, tx, ty)
-    if path p:
-      for t=1 upto length p:
-        if c: --
-        else: ..controls graph_pair_adjust(postcontrol(t-1) of p, tx, ty)
+    if path p :
+      for t=1 upto length p :
+        if c : --
+        else : ..controls graph_pair_adjust(postcontrol(t-1) of p, tx, ty)
           and graph_pair_adjust(precontrol t of p, tx, ty) ..
         fi
         graph_pair_adjust(point t of p, tx, ty)
       endfor
-      if cycle p: &cycle fi
-    fi;
-    if pair p: point 0 of fi r_
+      if cycle p : &cycle fi
+    fi ;
+    if pair p : point 0 of fi r_
   fi
-enddef;
-vardef graph_pair_adjust(expr p)(suffix tx, ty) = (tx xpart p, ty ypart p) enddef;
+enddef ;
+vardef graph_pair_adjust(expr p)(suffix tx, ty) = (tx xpart p, ty ypart p) enddef ;
 
 
 % Convert path p from user graph coords to internal graph coords.
 vardef graph_convert_user_path_to_internal primary p =
-  interim warningcheck:=0;
-  graph_scan_path(p, (abs X_.graph_coordinate_type<>linear) or (abs Y_.graph_coordinate_type<>linear),
-      if abs X_.graph_coordinate_type=log: graph_mlog fi,
-      if abs Y_.graph_coordinate_type=log: graph_mlog fi)
+  interim warningcheck :=0 ;
+  graph_scan_path(p,
+    (abs X_.graph_coordinate_type<>linear) or (abs Y_.graph_coordinate_type<>linear),
+    if abs X_.graph_coordinate_type=log : graph_mlog fi,
+    if abs Y_.graph_coordinate_type=log : graph_mlog fi)
     transformed  (identity
-      if X_.graph_coordinate_type<0:  xscaled -1  fi
-      if Y_.graph_coordinate_type<0:  yscaled -1  fi)
-enddef;
+      if X_.graph_coordinate_type<0 : xscaled -1 fi
+      if Y_.graph_coordinate_type<0 : yscaled -1 fi)
+enddef ;
 
 
 % Convert label location t_ from user graph coords to internal graph coords.
@@ -367,23 +389,23 @@ enddef;
 % or a single item of non-pair type, just return t_.  Unknown coordinates
 % produce unknown components in the result.
 vardef graph_label_convert_user_to_internal(text t_) =
-  save n_; n_=0;
-  interim warningcheck:=0;
-  if 0 for x_=t_: +1 if pair x_: +1 fi endfor <= 1:
+  save n_ ; n_=0;
+  interim warningcheck :=0 ;
+  if 0 for x_=t_ : +1 if pair x_ : +1 fi endfor <= 1 :
     t_
-  else:
-    n_0 = n_1 = 0;
+  else :
+    n_0 = n_1 = 0 ;
     point 0 of graph_convert_user_path_to_internal (
       for x_=
-        for y_=t_: if pair y_: xpart y_, ypart fi y_, endfor
-        0, 0:
-        if known x_: if string x_ : scantokens fi x_
-        else: hide(n_[n_]:=whatever) 0
+        for y_=t_ : if pair y_ : xpart y_, ypart fi y_, endfor
+        0, 0 :
+        if known x_ : if string x_ : scantokens fi x_
+        else : hide(n_[n_] :=whatever) 0
         fi
-        exitif incr n_=2;
+        exitif incr n_=2 ;
       ,endfor) + (n_0,n_1)
   fi
-enddef;
+enddef ;
 
 
 
@@ -393,57 +415,58 @@ enddef;
 % initial "%", and return true if at least one token is found.  The tokens
 % are stored in @#1, @#2, .. with "" in the last @#[] entry.
 vardef graph_read_line@#(expr f) =
-  save n_, s_; string s_;
-  s_ = readfrom f;
-  string @#[];
-  if s_<>EOF:
-    @#1 := loptok s_;
-    n_ = if @#1="%": 0 else: 1 fi;
-    forever:
-      @#[incr n_] := loptok s_;
-      exitif @#[n_]="";
+  save n_, s_ ; string s_;
+  s_ = readfrom f ;
+  string @#[] ;
+  if s_<>EOF :
+    @#0 := s_ ;
+    @#1 := loptok s_ ;
+    n_ = if @#1="%" : 0 else : 1 fi ;
+    forever :
+      @#[incr n_] := loptok s_ ;
+      exitif @#[n_]="" ;
     endfor
     @#1<>""
-  else: false
+  else : false
   fi
-enddef;
+enddef ;
 
 
 % Execute c for each line of data read from file f, and stop at the first
 % line with no data.  Commands c can use line number i and tokens $1, $2, ...
 def gdata(expr f)(suffix $)(text c) =
-  for i=1 upto infinity:
-    exitunless graph_read_line$(f);
+  for i=1 upto infinity :
+    exitunless graph_read_line$(f) ;
     c
   endfor
-enddef;
+enddef ;
 
 
 % Read a path from file f. The path is terminated by blank line or EOF.
 vardef graph_readpath(expr f) =
-  interim warningcheck:=0;
-  save s;
-  gdata(f, s, if i>1:--fi
-      if s2="": (            i, scantokens s1)
-      else:     (scantokens s1, scantokens s2) fi
+  interim warningcheck :=0 ;
+  save s ;
+  gdata(f, s, if i>1 :--fi
+      if s2="" : (            i, scantokens s1)
+      else :     (scantokens s1, scantokens s2) fi
   )
-enddef;
+enddef ;
 
 
 % Append coordinates t to polygonal path @#.  The coordinates can be numerics,
 % strings, or a single pair.
 vardef augment@#(text t) =
-  interim warningcheck := 0;
-  if not path begingroup @# endgroup:
-    Gerr(begingroup @# endgroup, "Cannot augment--not a path");
-  else:
-    def graph_comma= hide(def graph_comma=,enddef) enddef;
-    if known @#:  @#:=@#--  else:  @#=  fi
-    (for p=t:
-       graph_comma if string p: scantokens fi p
-     endfor);
+  interim warningcheck := 0 ;
+  if not path begingroup @# endgroup :
+    Gerr(begingroup @# endgroup, "Cannot augment--not a path") ;
+  else :
+    def graph_comma= hide(def graph_comma=,enddef) enddef ;
+    if known @# :  @# :=@#--  else :  @#=  fi
+    (for p=t :
+       graph_comma if string p : scantokens fi p
+     endfor) ;
   fi
-enddef;
+enddef ;
 
 
 
@@ -452,109 +475,113 @@ enddef;
 % Unknown pair components are set to 0 because glabel and gdotlabel understand
 % unknown coordinates as `0 in absolute units'.
 vardef graph_unknown_pair_bbox(expr p) =
-  if known p: addto graph_current_bb doublepath p;
-  else:
-    save x,y;
-    z = llcorner graph_current_bb;
-    if unknown xpart p: xpart p= else: x:= fi 0;
-    if unknown ypart p: ypart p= else: y:= fi 0;
-    addto graph_current_bb doublepath (p+z);
+  if known p : addto graph_current_bb doublepath p ;
+  else :
+    save x,y ;
+    z = llcorner graph_current_bb ;
+    if unknown xpart p : xpart p= else : x := fi 0 ;
+    if unknown ypart p : ypart p= else : y := fi 0 ;
+    addto graph_current_bb doublepath (p+z) ;
   fi
-  graph_current_bb := image(fill llcorner graph_current_bb..urcorner graph_current_bb--cycle);
-enddef;
+  graph_current_bb := image(fill llcorner graph_current_bb..urcorner graph_current_bb--cycle) ;
+enddef ;
 
 
 % Initiate a gdraw or gfill command.  This must be done before scanning the
 % argument, because that could invoke the `if known graph_plot_picture' test in a following
 % plot option .
-def graph_addto = graph_last_drawn:=graph_plot_picture:=nullpicture; addto graph_last_drawn enddef;
+def graph_addto =
+  graph_last_drawn := graph_plot_picture := nullpicture ; addto graph_last_drawn
+enddef;
 
 
 % Handle the part of a Gdraw command that uses path or data file p.
 def graph_draw expr p =
-  if string p: graph_convert_user_path_to_internal graph_readpath(p)
-  elseif path p or pair p: graph_convert_user_path_to_internal p
-  else: graph_error(p,"gdraw argument should be a data file or a path")
+  if string p : graph_convert_user_path_to_internal graph_readpath(p)
+  elseif path p or pair p : graph_convert_user_path_to_internal p
+  else : graph_error(p,"gdraw argument should be a data file or a path")
         origin
   fi
   withpen currentpen graph_withlist _op_
-enddef;
+enddef ;
 
 
 % Handle the part of a Gdraw command that uses path or data file p.
 def graph_fill expr p =
-  if string p: graph_convert_user_path_to_internal graph_readpath(p) --cycle
-  elseif cycle p: graph_convert_user_path_to_internal p
-  else: graph_error(p,"gfill argument should be a data file or a cyclic path")
+  if string p : graph_convert_user_path_to_internal graph_readpath(p) --cycle
+  elseif cycle p : graph_convert_user_path_to_internal p
+  else : graph_error(p,"gfill argument should be a data file or a cyclic path")
         origin..cycle
   fi graph_withlist _op_
-enddef;
+enddef ;
 
-def gdraw = graph_addto doublepath graph_draw enddef;
-def gfill = graph_addto contour graph_fill enddef;
+def gdraw = graph_addto doublepath graph_draw enddef ;
+def gfill = graph_addto contour graph_fill enddef ;
 
 
 % This is used in graph_draw and graph_fill to allow postprocessing graph_last_drawn
-def graph_withlist text t_ = t_; graph_post_draw; enddef;
+def graph_withlist text t_ = t_ ; graph_post_draw; enddef;
 
 
 % Set graph_plot_picture so the postprocessing step will plot picture p at each path knot.
 % Also select nullpen to suppress stroking.
 def plot expr p =
-  if known graph_plot_picture:
+  if known graph_plot_picture :
     withpen nullpen
-    hide (graph_plot_picture:=image(
-        if bounded p: for q within p: graph_addto_currentpicture q endfor    % Save memory
-        else: graph_addto_currentpicture p
+    hide (graph_plot_picture :=image(
+        if bounded p : for q within p : graph_addto_currentpicture q endfor    % Save memory
+        else : graph_addto_currentpicture p
         fi graph_setbounds origin..cycle))
   fi
-enddef;
+enddef ;
 
 % This hides a semicolon that could prematurely end graph_withlist's text argument
-def graph_addto_currentpicture primary p = addto currentpicture also p; enddef;
-def graph_setbounds = setbounds currentpicture to enddef;
+def graph_addto_currentpicture primary p = addto currentpicture also p ; enddef;
+def graph_setbounds = setbounds currentpicture to enddef ;
 
 
-def gdrawarrow = graph_number_of_arrowheads:=1; gdraw enddef;
-def gdrawdblarrow = graph_number_of_arrowheads:=2; gdraw enddef;
+def gdrawarrow = graph_number_of_arrowheads :=1 ; gdraw enddef;
+def gdrawdblarrow = graph_number_of_arrowheads :=2 ; gdraw enddef;
 
 
-% Post-process the filled or stroked picture graph_last_drawn as follows: (1) update
-% the bounding box information; (2) transfer it to graph_current_graph unless the pen has
-% been set to nullpen to disable stroking; (3) plot graph_plot_picture at each knot.
+% Post-process the filled or stroked picture graph_last_drawn as follows : (1) update
+% the bounding box information ; (2) transfer it to graph_current_graph unless the pen has
+% been set to nullpen to disable stroking ; (3) plot graph_plot_picture at each knot.
 vardef graph_post_draw =
-  save p;
-  path p; p=pathpart graph_last_drawn;
-  graph_unknown_pair_bbox(p);
-  if filled graph_last_drawn or not graph_is_null(penpart graph_last_drawn):
-    addto graph_current_graph also graph_last_drawn;
+  save p ;
+  path p ; p=pathpart graph_last_drawn;
+  graph_unknown_pair_bbox(p) ;
+  if filled graph_last_drawn or not graph_is_null(penpart graph_last_drawn) :
+    addto graph_current_graph also graph_last_drawn ;
   fi
-  if length graph_plot_picture>0:
-    for i=0 upto length p if cycle p: -1 fi:
-      addto graph_current_graph also graph_plot_picture shifted point i of p;
+  if length graph_plot_picture>0 :
+    for i=0 upto length p if cycle p : -1 fi :
+      addto graph_current_graph also graph_plot_picture shifted point i of p ;
     endfor
-    picture graph_plot_picture;
+    picture graph_plot_picture ;
   fi
-  if graph_number_of_arrowheads>0:
-    graph_draw_arrowhead(p, graph_with_pen_and_color(graph_last_drawn));
-    if graph_number_of_arrowheads>1: graph_draw_arrowhead(reverse p, graph_with_pen_and_color(graph_last_drawn)); fi
-    graph_number_of_arrowheads:=0;
+  if graph_number_of_arrowheads>0 :
+    graph_draw_arrowhead(p, graph_with_pen_and_color(graph_last_drawn)) ;
+    if graph_number_of_arrowheads>1 :
+      graph_draw_arrowhead(reverse p, graph_with_pen_and_color(graph_last_drawn)) ;
+    fi
+    graph_number_of_arrowheads :=0 ;
   fi
-enddef;
-vardef graph_is_null(expr p) = (urcorner p=origin) and (llcorner p=origin) enddef;
+enddef ;
+vardef graph_is_null(expr p) = (urcorner p=origin) and (llcorner p=origin) enddef ;
 
 
-vardef graph_draw_arrowhead(expr p)(text w) =        % Draw arrowhead for path p, with list w
+vardef graph_draw_arrowhead(expr p)(text w) = % Draw arrowhead for path p, with list w
   addto graph_current_graph also
     image(filldraw arrowhead(
-            graph_arrowhead_extent(precontrol infinity of p, point infinity of p)) w;
-        graph_setbounds point infinity of p..cycle);
-enddef;
+            graph_arrowhead_extent(precontrol infinity of p, point infinity of p)) w ;
+        graph_setbounds point infinity of p..cycle) ;
+enddef ;
 
 vardef graph_arrowhead_extent(expr p, q) =
-  if p<>q: (q - 100pt*unitvector(q-p)) -- fi
+  if p<>q : (q - 100pt*unitvector(q-p)) -- fi
   q
-enddef;
+enddef ;
 
 
 
@@ -562,46 +589,46 @@ enddef;
 
 % Argument c is a drawing command that needs an additional argument p that gives
 % a location in internal graph coords.  Draw in graph_current_graph enclosed in a setbounds
-% path.  Unknown components of p cause the setbounds path to have width or
-% height 1 instead of 0.  Then graph_unknown_pair_bbox sets these components to 0 and graph_picture_conversion
+% path. Unknown components of p cause the setbounds path to have width or height 1 instead of 0.
+% Then graph_unknown_pair_bbox sets these components to 0 and graph_picture_conversion
 % suppresses subsequent repositioning.
 def graph_draw_label(expr p)(suffix $)(text c) =
-  save sdim_; pair sdim_;
-  sdim_ := (if unknown xpart p: 1+ fi 0, if unknown ypart p: 1+ fi 0);
-  graph_unknown_pair_bbox(p);
+  save sdim_ ; pair sdim_;
+  sdim_ := (if unknown xpart p : 1+ fi 0, if unknown ypart p : 1+ fi 0) ;
+  graph_unknown_pair_bbox(p) ;
   addto graph_current_graph also
-    image(c(p); graph_setbounds p--p+sdim_--cycle) _op_
-enddef;
+    image(c(p) ; graph_setbounds p--p+sdim_--cycle) _op_
+enddef ;
 
 
 % Stash the result drawing command c in the graph_label table using with list w and
 % an index based on angle laboff$.
 vardef graph_stash_label(suffix $)(text c) text w =
-  graph_label[1.5+angle laboff$ /90] = image(c(origin) w);
-enddef;
+  graph_label[1.5+angle laboff$ /90] = image(c(origin) w) ;
+enddef ;
 
 
 def graph_label_location primary p =
-  if pair p: graph_draw_label(p)
-  elseif numeric p: graph_draw_label(point p of pathpart graph_last_drawn)
-  else: graph_stash_label
+  if pair p : graph_draw_label(p)
+  elseif numeric p : graph_draw_label(point p of pathpart graph_last_drawn)
+  else : graph_stash_label
   fi
-enddef;
+enddef ;
 
 
 % Place label p at user graph coords t using with list w. (t is a time, a pair
 % or 2 numerics or strings).
 vardef glabel@#(expr p)(text t) text w  =
-  graph_label_location graph_label_convert_user_to_internal(t)  (@#,label@#(p)) w; enddef;
+  graph_label_location graph_label_convert_user_to_internal(t)  (@#,label@#(p)) w ; enddef;
 
 
 % Place label p at user graph coords t using with list w and draw a dot there.
 % (t is a time, a pair, or 2 numerics or strings).
 vardef gdotlabel@#(expr p)(text t) text w =
-  graph_label_location graph_label_convert_user_to_internal(t)  (@#,dotlabel@#(p)) w; enddef;
+  graph_label_location graph_label_convert_user_to_internal(t)  (@#,dotlabel@#(p)) w ; enddef;
 
 
-def OUT = enddef;       % location text for outside labels
+def OUT = enddef ;       % location text for outside labels
 
 
 
@@ -610,32 +637,32 @@ def OUT = enddef;       % location text for outside labels
 % Grid lines and tick marks are transformed versions of the templates below.
 % In the template paths, (0,0) is on the edge of the frame and inward is to
 % the right.
-path Gtemplate.itick, Gtemplate.otick, Gtemplate.grid;
-Gtemplate.itick = origin--(7bp,0);
-Gtemplate.otick = (-7bp,0)--origin;
-Gtemplate.grid = origin--(1,0);
+path Gtemplate.itick, Gtemplate.otick, Gtemplate.grid ;
+Gtemplate.itick = origin--(7bp,0) ;
+Gtemplate.otick = (-7bp,0)--origin ;
+Gtemplate.grid = origin--(1,0) ;
 
-vardef itick@#(expr f,u) text w =  graph_tick_label(@#,@,false,f,u,w);  enddef;
+vardef itick@#(expr f,u) text w =  graph_tick_label(@#,@,false,f,u,w) ;  enddef;
 
-vardef otick@#(expr f,u) text w =  graph_tick_label(@#,@,false,f,u,w);  enddef;
+vardef otick@#(expr f,u) text w =  graph_tick_label(@#,@,false,f,u,w) ;  enddef;
 
-vardef  grid@#(expr f,u) text w =  graph_tick_label(@#,@,true,f,u,w);  enddef;
+vardef  grid@#(expr f,u) text w =  graph_tick_label(@#,@,true,f,u,w) ;  enddef;
 
 
 % Produce a tick or grid mark for label suffix $, Gtemplate suffix $$,
 % coordinate value u, and with list w.  Boolean c tells whether Gtemplate$$
-% needs scaling by X_.graph_dimensions or Y_.graph_dimensions, and f gives a format string or a label
-% picture.
+% needs scaling by X_.graph_dimensions or Y_.graph_dimensions,
+% and f gives a format string or a label picture.
 def graph_tick_label(suffix $,$$)(expr c, f, u)(text w) =
   graph_draw_label(graph_label_convert_user_to_internal(graph_generate_label_position($,u)),,draw graph_gridline_picture$($$,c,f,u,w) shifted)
-enddef;
+enddef ;
 
 
 % Generate label positioning arguments appropriate for label suffix $ and
 % coordinate u.
 def graph_generate_label_position(suffix $)(expr u) =
-  if xpart laboff.$=0: u,whatever else: whatever,u fi
-enddef;
+  if xpart laboff.$=0 : u,whatever else : whatever,u fi
+enddef ;
 
 
 % Generate a picture of a grid line labeled with coordinate value u, picture
@@ -643,218 +670,223 @@ enddef;
 % suffix $ identifies entries in the Gtemplate table, and boolean c tells
 % whether to scale Gtemplate$.
 vardef graph_gridline_picture@#(suffix $)(expr c, f, u)(text w) =
-  if unknown u: graph_error(u,"Label coordinate should be known"); nullpicture
-  else:
-    save p; path p;
-    interim warningcheck:=0;
-    graph_autogrid_needed:=false;
+  if unknown u : graph_error(u,"Label coordinate should be known") ; nullpicture
+  else :
+    save p ; path p;
+    interim warningcheck :=0 ;
+    graph_autogrid_needed :=false ;
     p = Gtemplate$ zscaled -laboff@#
-        if c: Gxyscale fi
-        shifted (((.5 + laboff@# dotprod (.5,.5)) * laboff@#) Gxyscale);
-    image(draw p w;
-        label@#(if string f: format(f,u) else: f fi, point 0 of p))
+        if c : Gxyscale fi
+        shifted (((.5 + laboff@# dotprod (.5,.5)) * laboff@#) Gxyscale) ;
+    image(draw p w ;
+        label@#(if string f : format(f,u) else : f fi, point 0 of p))
   fi
-enddef;
-def Gxyscale = xscaled X_.graph_dimensions yscaled Y_.graph_dimensions enddef;
+enddef ;
+def Gxyscale = xscaled X_.graph_dimensions yscaled Y_.graph_dimensions enddef ;
 
 
 % Draw the frame or the part corresponding to label suffix @# using with list w.
 vardef frame@# text w =
-  graph_frame_needed:=false;
-  picture p_;
+  graph_frame_needed :=false ;
+  picture p_ ;
   p_ = image(draw
-    if str@#<>"":  subpath round(angle laboff@#*graph_frame_pair_a+graph_frame_pair_b) of  fi
-    unitsquare Gxyscale  w);
-  graph_draw_label((whatever,whatever),,draw p_ shifted);
-enddef;
-pair graph_frame_pair_a; graph_frame_pair_a=(1,1)/90;     % unitsquare subpath is linear in label angle
-pair graph_frame_pair_b; graph_frame_pair_b=(.75,2.25);
+    if str@#<>"" :  subpath round(angle laboff@#*graph_frame_pair_a+graph_frame_pair_b) of  fi
+    unitsquare Gxyscale  w) ;
+  graph_draw_label((whatever,whatever),,draw p_ shifted) ;
+enddef ;
+pair graph_frame_pair_a ; graph_frame_pair_a=(1,1)/90;     % unitsquare subpath is linear in label angle
+pair graph_frame_pair_b ; graph_frame_pair_b=(.75,2.25);
 
 
 
 
 %%%%%%%%%%%%%%%%%%%%%%%%%% Automatic grid selection %%%%%%%%%%%%%%%%%%%%%%%%%%
 
-string Glmarks[];       % marking options per decade for logarithmic scales
-string Gumarks;         % mark spacing options per decade for linear scales
-string Gemarks;         % exponent spacing options for logarithmic scales
-newinternal Gmarks, Gminlog;
-Gmarks := 4;            % minimum number marks generated by auto.x or auto.y
-Gminlog := 3.0;         % revert to uniform marks when largest/smallest < this
+string Glmarks[] ;       % marking options per decade for logarithmic scales
+string Gumarks ;         % mark spacing options per decade for linear scales
+string Gemarks ;         % exponent spacing options for logarithmic scales
+newinternal Gmarks, Gminlog ;
+Gmarks  := 4 ;           % minimum number marks generated by auto.x or auto.y
+Gminlog := mlog 3 ;      % revert to uniform marks when largest/smallest < this
 
-def Gfor(text t) = for i=t endfor enddef;  % to shorten the mark templates below
-Glmarks[1]="1,2,5";
-Glmarks[2]="1,1.5,2,3,4,5,7";
-Glmarks[3]="1Gfor(6upto10:,i/5)Gfor(5upto10:,i/2)Gfor(6upto9:,i)";
-Glmarks[4]="1Gfor(11upto20:,i/10)Gfor(11upto25:,i/5)Gfor(11upto19:,i/2)";
-Glmarks[5]="1Gfor(21upto40:,i/20)Gfor(21upto50:,i/10)Gfor(26upto49:,i/5)";
-Gumarks="10,5,2";       % start with 10 and go down; a final `,1' is appended
-Gemarks="20,10,5,2,1";
+def Gfor(text t) = for i=t endfor enddef ;  % to shorten the mark templates below
+Glmarks[1]="1,2,5" ;
+Glmarks[2]="1,1.5,2,3,4,5,7" ;
+Glmarks[3]="1Gfor(6upto10 :,i/5)Gfor(5upto10 :,i/2)Gfor(6upto9 :,i)" ;
+Glmarks[4]="1Gfor(11upto20 :,i/10)Gfor(11upto25 :,i/5)Gfor(11upto19 :,i/2)" ;
+Glmarks[5]="1Gfor(21upto40 :,i/20)Gfor(21upto50 :,i/10)Gfor(26upto49 :,i/5)" ;
+Gumarks="10,5,2" ;       % start with 10 and go down; a final `,1' is appended
+Gemarks="20,10,5,2,1" ;
 
 
 % Determine the X_ or Y_ bounds on the range to be covered by automatic grid
 % marks.  Suffix @# is X_ or Y_.  The result is log or linear to specify the
 % type of grid spacing to use.  Bounds are returned in variables local to
-% begingraph..endgraph: pairs graph_modified_lower and graph_modified_higher
+% begingraph..endgraph : pairs graph_modified_lower and graph_modified_higher
 %  are upper and lower bounds in
 % `modified exponential form'.  In modified exponential form, (x,y) means
 % (x/1000)*10^y, where 1000<=abs x<10000.
 vardef graph_bounds@# =
-  interim warningcheck:=0;
-  save l, h;
-  graph_set_default_bounds;
-  if @#graph_coordinate_type>0: (l,h) else: -(h,l) fi = (@#low, @#high);
-  if abs @#graph_coordinate_type=log:
-    graph_modified_lower  := graph_Meform(l)+graph_modified_bias;
-    graph_modified_higher := graph_Meform(h)+graph_modified_bias;
-    if h-l >=mlog Gminlog: log else: linear fi
-  else:
-    graph_modified_lower  := graph_Feform(l)+graph_modified_bias;
-    graph_modified_higher := graph_Feform(h)+graph_modified_bias;
+  interim warningcheck :=0 ;
+  save l, h ;
+  graph_set_default_bounds ;
+  if @#graph_coordinate_type>0 : (l,h) else : -(h,l) fi = (@#low, @#high) ;
+  if abs @#graph_coordinate_type=log :
+    graph_modified_lower  := graph_Meform(l)+graph_modified_bias ;
+    graph_modified_higher := graph_Meform(h)+graph_modified_bias ;
+    if h-l >= Gminlog : log else : linear fi
+  else :
+    graph_modified_lower  := graph_Feform(l)+graph_modified_bias ;
+    graph_modified_higher := graph_Feform(h)+graph_modified_bias ;
     linear
   fi
-enddef;
-pair graph_modified_bias; graph_modified_bias=(0,3);
-pair graph_modified_lower, graph_modified_higher;
+enddef ;
+pair graph_modified_bias ; graph_modified_bias=(0,3);
+pair graph_modified_lower, graph_modified_higher ;
 
 
 % Scan Glmarks[k] and evaluate tokens t for each m where l<=m<=h.
 def graph_scan_marks(expr k, l, h)(text t) =
-  for m=scantokens Glmarks[k]:
-    exitif m>h;
-    if m>=l: t fi
+  for m=scantokens Glmarks[k] :
+    exitif m>h ;
+    if m>=l : t fi
   endfor
-enddef;
+enddef ;
 
 
 % Scan Gmark[k] and evaluate tokens t for each m and e where m*10^e belongs
 % between l and h (inclusive), where both l and h are in modified exponent form.
 def graph_scan_mark(expr k, l, h)(text t) =
-  for e=ypart l upto ypart h:
-    graph_scan_marks(k, if e>ypart l: 1 else: xpart l/1000 fi,
-        if e<ypart h: 10 else: xpart h/1000 fi,  t)
+  for e=ypart l upto ypart h :
+    graph_scan_marks(k, if e>ypart l : 1 else : xpart l/1000 fi,
+        if e<ypart h : 10 else : xpart h/1000 fi,  t)
   endfor
-enddef;
+enddef ;
 
 
 % Select a k for which graph_scan_mark(k,...) gives enough marks.
 vardef graph_select_mark =
-  save k;
-  k = 0;
-  forever:
-    exitif unknown Glmarks[k+1];
-    exitif 0 graph_scan_mark(incr k, graph_modified_lower, graph_modified_higher, +1) >= Gmarks;
+  save k ;
+  k = 0 ;
+  forever :
+    exitif unknown Glmarks[k+1] ;
+    exitif 0 graph_scan_mark(incr k, graph_modified_lower, graph_modified_higher, +1) >= Gmarks ;
   endfor
   k
-enddef;
+enddef ;
 
 
 % Try to select an exponent spacing from Gemarks.  If successful, set @# and
 % return true
 vardef graph_select_exponent_mark@# =
-  numeric @#;
-  for e=scantokens Gemarks:
-    @# = e;
-    exitif floor(ypart graph_modified_higher/e)-floor(graph_modified_exponent_ypart(graph_modified_lower)/e) >= Gmarks;
-    numeric @#;
+  numeric @# ;
+  for e=scantokens Gemarks :
+    @# = e ;
+    exitif floor(ypart graph_modified_higher/e) -
+           floor(graph_modified_exponent_ypart(graph_modified_lower)/e) >= Gmarks ;
+    numeric @# ;
   endfor
   known @#
-enddef;
+enddef ;
 
-vardef graph_modified_exponent_ypart(expr p) = ypart p  if xpart p=1000: -1 fi  enddef;
+vardef graph_modified_exponent_ypart(expr p) = ypart p  if xpart p=1000 : -1 fi  enddef ;
 
 
 % Compute the mark spacing d between xpart graph_modified_lower and xpart graph_modified_higher.
 vardef graph_tick_mark_spacing =
-  interim warningcheck:=0;
-  save m, n, d;
-  m = Gmarks;
+  interim warningcheck :=0 ;
+  save m, n, d ;
+  m = Gmarks ;
   n = 1 for i=1 upto
-                (mlog(xpart graph_modified_higher-xpart graph_modified_lower) - mlog m)/mlogten:
-        *10 endfor;
-  if n<=1000:
-    for x=scantokens Gumarks:
-      d = n*x;
-      exitif 0 graph_generate_numbers(d,+1)>=m;
-      numeric d;
+                (mlog(xpart graph_modified_higher-xpart graph_modified_lower) - mlog m)/mlogten :
+        *10 endfor ;
+  if n<=1000 :
+    for x=scantokens Gumarks :
+      d = n*x ;
+      exitif 0 graph_generate_numbers(d,+1)>=m ;
+      numeric d ;
     endfor
   fi
-  if known d: d else: n fi
-enddef;
+  if known d : d else : n fi
+enddef ;
 
 
 def graph_generate_numbers(expr d)(text t) =
-  for m = d*ceiling(xpart graph_modified_lower/d) step d until xpart graph_modified_higher:
+  for m = d*ceiling(xpart graph_modified_lower/d) step d until xpart graph_modified_higher :
     t
   endfor
-enddef;
+enddef ;
 
 
 % Evaluate tokens t for exponents e in multiples of d in the range determined
 % by graph_modified_lower and graph_modified_higher.
 def graph_generate_exponents(expr d)(text t) =
   for e = d*floor(graph_modified_exponent_ypart(graph_modified_lower)/d+1)
-      step d until d*floor(ypart graph_modified_higher/d):  t
+      step d until d*floor(ypart graph_modified_higher/d) :  t
   endfor
-enddef;
+enddef ;
 
 
-% Adjust graph_modified_lower and graph_modified_higher so their exponent parts match and they are in true
-% exponent form ((x,y) means x*10^y).  Return the new exponent.
+% Adjust graph_modified_lower and graph_modified_higher so their exponent parts match
+% and they are in true exponent form ((x,y) means x*10^y).  Return the new exponent.
 vardef graph_match_exponents =
-  interim warningcheck := 0;
-  save e;
-  e+3 = if graph_modified_lower=graph_modified_bias: ypart graph_modified_higher
-        elseif graph_modified_higher=graph_modified_bias: ypart graph_modified_lower
-        else: max(ypart graph_modified_lower, ypart graph_modified_higher) fi;
-  forsuffixes $=graph_modified_lower, graph_modified_higher:
-    $ := (xpart $ for i=ypart $ upto e+2: /(10) endfor, e);
+  interim warningcheck := 0 ;
+  save e ;
+  e+3 = if graph_modified_lower=graph_modified_bias : ypart graph_modified_higher
+        elseif graph_modified_higher=graph_modified_bias : ypart graph_modified_lower
+        else : max(ypart graph_modified_lower, ypart graph_modified_higher) fi ;
+  forsuffixes $=graph_modified_lower, graph_modified_higher :
+    $ := (xpart $ for i=ypart $ upto e+2 : /(10) endfor, e) ;
   endfor
   e
-enddef;
+enddef ;
 
 
 % Assume e is an integer and either m=0 or 1<=abs(m)<10000.  Find m*(10^e)
 % and represent the result as a string if its absolute value would be at least
 % 4096 or less than .1.  It is OK to return 0 as a string or a numeric.
 vardef graph_factor_and_exponent_to_string(expr m, e) =
-  if (e>3)or(e<-4):
+  if (e>3)or(e<-4) :
     decimal m & "e" & decimal e
-  elseif e>=0:
-    if abs m<infinity/Ten_to[e]:
+  elseif e>=0 :
+    if abs m<infinity/Ten_to[e] :
           m*Ten_to[e]
-    else: decimal m & "e" & decimal e
+    else : decimal m & "e" & decimal e
     fi
-  else:
-    save x; x=m/Ten_to[-e];
-    if abs x>=.1: x else: decimal m & "e" & decimal e fi
+  else :
+    save x ; x=m/Ten_to[-e];
+    if abs x>=.1 : x else : decimal m & "e" & decimal e fi
   fi
-enddef;
+enddef ;
 
 
 def auto suffix $ =
   hide(def graph_comma= hide(def graph_comma=,enddef) enddef)
-  if graph_bounds.graph_suffix($)=log:
-    if graph_select_exponent_mark.graph_exponent:  graph_generate_exponents(graph_exponent, graph_comma graph_factor_and_exponent_to_string(1,e))
-    else: 
-      graph_scan_mark(graph_select_mark, graph_modified_lower, graph_modified_higher, graph_comma graph_factor_and_exponent_to_string(m,e))
+  if graph_bounds.graph_suffix($)=log :
+    if graph_select_exponent_mark.graph_exponent :
+      graph_generate_exponents(graph_exponent,
+        graph_comma graph_factor_and_exponent_to_string(1,e))
+    else : 
+      graph_scan_mark(graph_select_mark, graph_modified_lower, graph_modified_higher,
+        graph_comma graph_factor_and_exponent_to_string(m,e))
     fi
-  else:
-    hide(graph_exponent:=graph_match_exponents)
-    graph_generate_numbers(graph_tick_mark_spacing, graph_comma graph_factor_and_exponent_to_string(m,graph_exponent))
+  else :
+    hide(graph_exponent :=graph_match_exponents)
+    graph_generate_numbers(graph_tick_mark_spacing,
+      graph_comma graph_factor_and_exponent_to_string(m,graph_exponent))
   fi
-enddef;
+enddef ;
 
 
-string Autoform; Autoform = "%g";
+string Autoform ; Autoform = "%g";
 
 %vardef autogrid(suffix tx, ty) text w =
-%  graph_autogrid_needed:=false;
-%  if str tx<>"": for x=auto.x: tx(Autoform,x) w; endfor fi
-%  if str ty<>"": for y=auto.y: ty(Autoform,y) w; endfor fi
-%enddef;
+%  graph_autogrid_needed :=false ;
+%  if str tx<>"" : for x=auto.x : tx(Autoform,x) w ; endfor fi
+%  if str ty<>"" : for y=auto.y : ty(Autoform,y) w ; endfor fi
+%enddef ;
 
-% We redefine autogrid from graph.mp adding the possibility of differing X and Y
+% We redefine autogrid, adding the possibility of differing X and Y
 % formats.
 
 % string Autoform_X ; Autoform_X := "@.0e" ;
@@ -900,21 +932,21 @@ enddef ;
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% endgraph %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
 def endgraph =
-  if graph_autogrid_needed: autogrid(otick.bot, otick.lft); fi
-  if graph_frame_needed:    frame; fi
-  setcoords(linear,linear);
-  interim truecorners:=1;
-  for  b=bbox graph_finished_graph:
-    setbounds graph_finished_graph to b;
-    for i=0 step .5 until 3.5:
-      if known graph_label[i]:
-        addto graph_finished_graph also graph_label[i] shifted point i of b;
+  if graph_autogrid_needed : autogrid(otick.bot, otick.lft) ; fi
+  if graph_frame_needed :    frame ; fi
+  setcoords(linear,linear) ;
+  interim truecorners :=1 ;
+  for  b=bbox graph_finished_graph :
+    setbounds graph_finished_graph to b ;
+    for i=0 step .5 until 3.5 :
+      if known graph_label[i] :
+        addto graph_finished_graph also graph_label[i] shifted point i of b ;
       fi
     endfor
   endfor
   graph_finished_graph
   endgroup
-enddef;
+enddef ;
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
@@ -935,18 +967,18 @@ vardef escaped_format(expr s) =
 enddef ;
 
 vardef strfmt(expr f, x) =
-    "\MPgraphformat{" & escaped_format(f) & "}{" & (if string x : x else: decimal x fi) & "}"
+    "\MPgraphformat{" & escaped_format(f) & "}{" & (if string x : x else : decimal x fi) & "}"
 enddef ;
 
 vardef format(expr f, x) = textext(strfmt(f, x)) enddef ;
 
-% A couple of extensions:
+% A couple of extensions :
 
-% Define a function plotsymbol() returning a picture: 10 different shapes,
+% Define a function plotsymbol() returning a picture : 10 different shapes,
 % unfilled outline, interior filled with different shades of the background.
 % This allows overlapping points on a plot to be more distinguishable.
 
-vardef graph_shapesize = .35BodyFontSize enddef ;
+vardef graph_shapesize = .33BodyFontSize enddef ;
 
 path graph_shape[] ; % (internal) symbol path
 
@@ -1005,9 +1037,9 @@ endfor cycle ;
 
 graph_shape[34] := graph_shape[24] rotated 45 ;
 
-% usage: gdraw p plot plotsymbol(1,red,1) ;      % a filled red circle
-% usage: gdraw p plot plotsymbol(14,blue,0) ;    % a blue square
-% usage: gdraw p plot plotsymbol(4,green,0.5) ;  % a 50% filled green diamond
+% usage : gdraw p plot plotsymbol(1,red,1) ;      % a filled red circle
+% usage : gdraw p plot plotsymbol(14,blue,0) ;    % a blue square
+% usage : gdraw p plot plotsymbol(4,green,0.5) ;  % a 50% filled green diamond
 
 def          stars(expr c, f) = plotsymbol(25,c,f) enddef ; % a 5-point star
 def         points(expr c, f) = plotsymbol( 0,c,f) enddef ;
@@ -1045,6 +1077,19 @@ def plotsymbol(expr n,c,f) = % (number,color,color|number)
     fi
 enddef ;
 
+% standard resistance color code: rainbow sequence (from /usr/share/X11/rgb.txt)
+color resistance_color[] ;                      string resistance_name[] ;
+resistance_color0 = (0,0,0) ;                   resistance_name0 = "black" ;
+resistance_color1 = (165/255,42/255,42/255) ;   resistance_name1 = "brown" ;
+resistance_color2 = (1,0,0) ;                   resistance_name2 = "red" ;
+resistance_color3 = (1,165/255,0) ;             resistance_name3 = "orange" ;
+resistance_color4 = (1,1,0) ;                   resistance_name4 = "yellow" ;
+resistance_color5 = (0,1,0) ;                   resistance_name5 = "green" ;
+resistance_color6 = (0,0,1) ;                   resistance_name6 = "blue" ;
+resistance_color7 = (148/255,0,211/255) ;       resistance_name7 = "darkviolet" ;
+resistance_color8 = (190/255,190/255,190/255) ; resistance_name8 = "gray" ;
+resistance_color9 = (1,1,1) ;                   resistance_name9 = "white" ;
+
 % The following extensions are not specific to graph and could be moved to metafun...
 
 % sort a path. Efficient en memory use, not so efficient in sorting long paths...
@@ -1094,7 +1139,7 @@ enddef ;
 
 % shift a path, point by point
 %
-% example:
+% example :
 %
 %   p1 := addnoisetopath(p0,(.1normaldeviate,.1normaldeviate)) ;
 
@@ -1103,7 +1148,7 @@ vardef addnoisetopath (suffix p) (text t) =
     hide(pair p_i)
     (for i=0 upto length p :
         if i>0 : -- fi
-        hide(p_i := point i of p; x := xpart p_i; y := ypart p_i)z shifted t
+        hide(p_i := point i of p ; x := xpart p_i; y := ypart p_i)z shifted t
     endfor)
     fi
 enddef ;
@@ -1119,7 +1164,7 @@ enddef ;
 
 % least-squares "fit" to a polynomial
 %
-% example:
+% example :
 %
 %   path p[] ;
 %   numeric a[] ; a0 := 1 ; a1 := .1 ; a2 := .01 ; a3 := .001 ; a4 := 0.0001 ;
@@ -1136,7 +1181,7 @@ enddef ;
 %   linear_fit(p1, c, 1) ;
 %   gdraw functionpath(p1,linear_function(c,x)) dashed evenly ;
 
-% a polynomial function:
+% a polynomial function :
 %
 % y = a0 + a1 * x + a2 * x^2 + ... + a[n] * x^n
 
@@ -1144,7 +1189,7 @@ vardef polynomial_function (suffix $) (expr n, x) =
     (for j=0 upto n : + $[j]*(x**j) endfor) % no ;
 enddef ;
 
-% find the determinant of a (n+1)*(n+1) matrix; indices run from 0 to n
+% find the determinant of a (n+1)*(n+1) matrix ; indices run from 0 to n
 
 vardef det (suffix $) (expr n) =
     hide(
@@ -1173,8 +1218,8 @@ vardef det (suffix $) (expr n) =
             exitif determinant=0 ;
             determinant := determinant * $[k][k] ;
             if k<n : % subtract row k from lower rows to get a diagonal matrix
-                for j=k+1 upto n:
-                    for i=k+1 upto n:
+                for j=k+1 upto n :
+                    for i=k+1 upto n :
                         $[j][i] := $[j][i]-$[j][k]*$[k][i]/$[k][k] ;
                     endfor
                 endfor
@@ -1188,7 +1233,7 @@ numeric fit_chi_squared ;
 
 % least-squares fit of a polynomial $ of order n to a path p (unweighted)
 %
-% reference: P. R. Bevington, "Data Reduction and Error Analysis for the Physical
+% reference : P. R. Bevington, "Data Reduction and Error Analysis for the Physical
 % Sciences", McGraw-Hill, New York 1969.
 
 vardef polynomial_fit (suffix p, $) (expr n) (text t) =
@@ -1208,7 +1253,7 @@ vardef polynomial_fit (suffix p, $) (expr n) (text t) =
             sumy[i] := 0 ;
         endfor
         for i=0 upto length p :
-            clearxy; z = point i of p ;
+            clearxy ; z = point i of p ;
             w := if length(t) > 0 : t else : 1 fi ; % weight
             x1 := w ;
             for j=0 upto 2n :
@@ -1314,9 +1359,9 @@ vardef power_law_fit (suffix p, $) (text t) =
     $1 := exp(a0) ;
 enddef ;
 
-% gaussian: y = a2 * exp(-ln(2)*((x-a0)/a1)^2)
+% gaussian : y = a2 * exp(-ln(2)*((x-a0)/a1)^2)
 %
-% a1 is the hwhm; sigma := a1/sqrt(2ln(2)) or a1/1.17741
+% a1 is the hwhm ; sigma := a1/sqrt(2ln(2)) or a1/1.17741
 
 newinternal lntwo ; lntwo := ln(2) ; % brrr, why not inline it