--- a/scripts/plot/private/__bar__.m	Sun Sep 29 18:14:31 2013 -0400
+++ b/scripts/plot/private/__bar__.m	Mon Sep 30 16:50:41 2013 -0700
@@ -25,14 +25,15 @@
 
 function varargout = __bar__ (vertical, func, varargin)
 
-  [hax, varargin, nargs] = __plt_get_axis_arg__ (func, varargin{:});
+  [hax, varargin, nargin] = __plt_get_axis_arg__ (func, varargin{:});
 
   ## Slightly smaller than 0.8 to avoid clipping issue in gnuplot 4.0
   width = 0.8 - 10 * eps;
   group = true;
-  bv = 0;
+  histc = NA;
+  bv = 0;  # BaseValue
 
-  if (nargs > 1 && isnumeric (varargin{2}))
+  if (nargin > 1 && isnumeric (varargin{2}))
     x = varargin{1};
     if (isvector (x))
       x = x(:);
@@ -65,13 +66,21 @@
 
   newargs = {};
   have_line_spec = false;
-  while (idx <= nargs)
+  while (idx <= nargin)
     if (ischar (varargin{idx}) && strcmpi (varargin{idx}, "grouped"))
       group = true;
       idx++;
     elseif (ischar (varargin{idx}) && strcmpi (varargin{idx}, "stacked"))
       group = false;
       idx++;
+    elseif (ischar (varargin{idx}) && strcmpi (varargin{idx}, "histc"))
+      group = true;
+      histc = true; 
+      idx++;
+    elseif (ischar (varargin{idx}) && strcmpi (varargin{idx}, "hist"))
+      group = true;
+      histc = false;
+      idx++;
     else
       if ((ischar (varargin{idx}) || iscellstr (varargin{idx}))
           && ! have_line_spec)
@@ -87,77 +96,116 @@
       endif
       if (isscalar (varargin{idx}))
         width = varargin{idx++};
-      elseif (idx == nargs)
-        newargs = [newargs,varargin(idx++)];
+      elseif (idx == nargin)
+        newargs = [newargs, varargin(idx++)];
       elseif (ischar (varargin{idx})
               && strcmpi (varargin{idx}, "basevalue")
               && isscalar (varargin{idx+1}))
         bv = varargin{idx+1};
         idx += 2;
       else
-        newargs = [newargs,varargin(idx:idx+1)];
+        newargs = [newargs, varargin(idx:idx+1)];
         idx += 2;
       endif
     endif
   endwhile
 
-  xlen = rows (x);
-  ylen = rows (y);
-
-  if (xlen != ylen)
+  ngrp = rows (x);
+  if (ngrp != rows (y))
     error ("%s: length of X and Y must be equal", func);
   endif
   if (any (x(2:end) < x(1:end-1)))
     error ("%s: X vector values must be in ascending order", func);
   endif
 
-  ycols = columns (y);
+  nbars = columns (y);
+
+  ## Column width is 1 for 'hist*' styles.  Otherwise, same as group width.
+  if (nbars == 1)
+    cwidth = 1;
+    gwidth = width;
+  elseif (islogical (histc))
+    cwidth = 1;
+    gwidth = width^2;
+  else
+    cwidth = gwidth = width;
+  endif
+
+  ## Complicated algorithm sizes bars with unitless parameter width.
+  ## If width is 1.0, adjacent bars in a group are touching.
+  ## Otherwise, bar size is cwidth and the remaining space is split evenly on
+  ## either side of the bar.  For the default 0.8, spacing is [0.1 0.8 0.1].
+  ## Groups of bars are spaced by gwidth.  If gwidth is 1.0 then adjacent
+  ## groups will just touch.
   if (numel (x) > 1)
     cutoff = min (diff (double (x))) / 2;
   else
     cutoff = 1;
   endif
   if (group)
-    delta_p = delta_m = repmat (cutoff * width / ycols, size (x));
+    gdelta = cutoff * gwidth / nbars; 
+    cdelta = repmat ((1 - ((1 - cwidth) / 2)) * gdelta, size (x));
   else
-    delta_p = delta_m = repmat (cutoff * width, size (x));
+    cdelta = repmat (cutoff * gwidth, size (x));
   endif
-  x1 = (x - delta_m)(:)';
-  x2 = (x + delta_p)(:)';
-  xb = repmat ([x1; x1; x2; x2](:), 1, ycols);
+  x1 = (x - cdelta)(:)';
+  x2 = (x + cdelta)(:)';
+  xb = repmat ([x1; x1; x2; x2](:), 1, nbars);
 
   if (group)
-    offset = ((delta_p + delta_m) * [-(ycols - 1) / 2 : (ycols - 1) / 2]);
-    xb(1:4:4*ylen,:) += offset;
-    xb(2:4:4*ylen,:) += offset;
-    xb(3:4:4*ylen,:) += offset;
-    xb(4:4:4*ylen,:) += offset;
+    if (islogical (histc) && histc)
+      offset = 2*cdelta * [0:(nbars-1)] + cdelta(1);  # not centered
+    else
+      offset = 2*cdelta * [-(nbars - 1) / 2 : (nbars - 1) / 2];
+    endif
+
+    xb(1:4:4*ngrp,:) += offset + (1-cwidth) / 2 * (2 * gdelta);
+    xb(2:4:4*ngrp,:) += offset + (1-cwidth) / 2 * (2 * gdelta);
+    xb(3:4:4*ngrp,:) += offset - (1-cwidth) / 2 * (2 * gdelta);
+    xb(4:4:4*ngrp,:) += offset - (1-cwidth) / 2 * (2 * gdelta);
+
     y0 = zeros (size (y)) + bv;
     y1 = y;
   else
     y1 = cumsum (y,2);
-    y0 = [zeros(ylen,1)+bv, y1(:,1:end-1)];
+    y0 = [zeros(ngrp,1)+bv, y1(:,1:end-1)];
   endif
 
-  yb = zeros (4*ylen, ycols);
-  yb(1:4:4*ylen,:) = y0;
-  yb(2:4:4*ylen,:) = y1;
-  yb(3:4:4*ylen,:) = y1;
-  yb(4:4:4*ylen,:) = y0;
+  yb = zeros (4*ngrp, nbars);
+  yb(1:4:4*ngrp,:) = y0;
+  yb(2:4:4*ngrp,:) = y1;
+  yb(3:4:4*ngrp,:) = y1;
+  yb(4:4:4*ngrp,:) = y0;
 
-  xb = reshape (xb, [4, numel(xb) / 4 / ycols, ycols]);
-  yb = reshape (yb, [4, numel(yb) / 4 / ycols, ycols]);
+  xb = reshape (xb, [4, ngrp, nbars]);
+  yb = reshape (yb, [4, ngrp, nbars]);
 
   if (nargout < 2)
-  oldfig = [];
-  if (! isempty (hax))
-    oldfig = get (0, "currentfigure");
-  endif
+    oldfig = [];
+    if (! isempty (hax))
+      oldfig = get (0, "currentfigure");
+    endif
     unwind_protect
       hax = newplot (hax);
 
-      htmp = bars (hax, vertical, x, y, xb, yb, width, group,
+      htmp = bars (hax, vertical, x, y, xb, yb, gwidth, group,
                    have_line_spec, bv, newargs{:});
+
+      if (! ishold (hax))
+        if (all (x(:,1) == fix (x(:,1))))
+          if (vertical)
+            set (hax, "xtick", x(:,1));
+          else
+            set (hax, "ytick", x(:,1));
+          endif
+        endif
+        ## Hack prevents color and xlim setting changes when basevalue changes.
+        if (vertical)
+          set (hax, "clim", [0 1], "xlimmode", "manual");
+        else
+          set (hax, "clim", [0 1], "ylimmode", "manual");
+        endif
+      endif
     unwind_protect_cleanup
       if (! isempty (oldfig))
         set (0, "currentfigure", oldfig);
@@ -178,52 +226,50 @@
 
 endfunction
 
-function tmp = bars (ax, vertical, x, y, xb, yb, width, group, have_color_spec, base_value, varargin)
+function hglist = bars (hax, vertical, x, y, xb, yb, width, group, have_color_spec, base_value, varargin)
 
-  ycols = columns (y);
-  clim = get (ax, "clim");
-  tmp = [];
+  nbars = columns (y);
+  clim = get (hax, "clim");
+  hglist = [];
 
-  for i = 1:ycols
+  for i = 1:nbars
     hg = hggroup ();
-    tmp = [tmp; hg];
+    hglist = [hglist; hg];
     args = __add_datasource__ ("bar", hg, {"x", "y"}, varargin{:});
 
     if (vertical)
       if (! have_color_spec)
-        if (ycols == 1)
+        if (nbars == 1)
           lev = clim(1);
         else
-          lev = (i - 1) * (clim(2) - clim(1)) / (ycols - 1) - clim(1);
+          lev = (i - 1) * (clim(2) - clim(1)) / (nbars - 1) - clim(1);
         endif
-        h = patch (ax, xb(:,:,i), yb(:,:,i), "FaceColor", "flat",
-                   "cdata", lev, "parent", hg);
+        h = patch (hax, xb(:,:,i), yb(:,:,i),
+                        "FaceColor", "flat", "cdata", lev, "parent", hg);
       else
-        h = patch (ax, xb(:,:,i), yb(:,:,i), "parent", hg);
+        h = patch (hax, xb(:,:,i), yb(:,:,i), "parent", hg);
       endif
     else
       if (! have_color_spec)
-        if (ycols == 1)
+        if (nbars == 1)
           lev = clim(1);
         else
-          lev = (i - 1) * (clim(2) - clim(1)) / (ycols - 1) - clim(1);
+          lev = (i - 1) * (clim(2) - clim(1)) / (nbars - 1) - clim(1);
         endif
-        h = patch (ax, yb(:,:,i), xb(:,:,i), "FaceColor", "flat",
-                   "cdata", lev, "parent", hg);
+        h = patch (hax, yb(:,:,i), xb(:,:,i),
+                        "FaceColor", "flat", "cdata", lev, "parent", hg);
       else
-        h = patch (ax, yb(:,:,i), xb(:,:,i), "parent", hg);
+        h = patch (hax, yb(:,:,i), xb(:,:,i), "parent", hg);
       endif
     endif
 
     if (i == 1)
-      x_axis_range = get (ax, "xlim");
-      h_baseline = line (ax, x_axis_range, [base_value, base_value],
-                         "color", [0, 0, 0]);
-      set (h_baseline, "handlevisibility", "off");
-      set (h_baseline, "xliminclude", "off");
-      addlistener (ax, "xlim", @update_xlim);
-      addlistener (h_baseline, "ydata", @update_baseline);
-      addlistener (h_baseline, "visible", @update_baseline);
+      ## Add baseline object the first time through loop
+      x_axis_range = get (hax, "xlim");
+      h_baseline = line (hax, x_axis_range, [base_value, base_value],
+                             "color", [0, 0, 0]);
+      set (h_baseline, "handlevisibility", "off", "xliminclude", "off");
+      set (h_baseline, "parent", get (hg, "parent"));
     endif
 
     ## Setup the hggroup and listeners
@@ -252,14 +298,14 @@
     addlistener (hg, "horizontal", @update_group);
 
     addproperty ("edgecolor", hg, "patchedgecolor", get (h, "edgecolor"));
-    addproperty ("linewidth", hg, "patchlinewidth", get (h, "linewidth"));
+    addproperty ("facecolor", hg, "patchfacecolor", get (h, "facecolor"));
     addproperty ("linestyle", hg, "patchlinestyle", get (h, "linestyle"));
-    addproperty ("facecolor", hg, "patchfacecolor", get (h, "facecolor"));
+    addproperty ("linewidth", hg, "patchlinewidth", get (h, "linewidth"));
 
     addlistener (hg, "edgecolor", @update_props);
-    addlistener (hg, "linewidth", @update_props);
+    addlistener (hg, "facecolor", @update_props);
     addlistener (hg, "linestyle", @update_props);
-    addlistener (hg, "facecolor", @update_props);
+    addlistener (hg, "linewidth", @update_props);
 
     if (isvector (x))
       addproperty ("xdata", hg, "data", x);
@@ -272,24 +318,27 @@
     addlistener (hg, "ydata", @update_data);
 
     addproperty ("bargroup", hg, "data");
-    set (tmp, "bargroup", tmp);
+    set (hglist, "bargroup", hglist);
     if (! isempty (args))
       set (hg, args{:});
     endif
-    if (i == 1)
-      set (h_baseline, "parent", get (hg, "parent"));
-    endif
   endfor
 
-  update_xlim (ax, []);
+  update_xlim (hax, []);
+  ## Add listeners outside of for loop to prevent constant updating during
+  ## creation of plot when patch objects are added.
+  addlistener (hax, "xlim", @update_xlim);
+  addlistener (h_baseline, "ydata", @update_baseline);
+  addlistener (h_baseline, "visible", @update_baseline);
+
 endfunction
 
-function update_xlim (h, d)
+function update_xlim (h, ~)
   kids = get (h, "children");
   xlim = get (h, "xlim");
 
   for i = 1 : length (kids)
-    obj = get (kids (i));
+    obj = get (kids(i));
     if (strcmp (obj.type, "hggroup") && isfield (obj, "baseline"))
       if (any (get (obj.baseline, "xdata") != xlim))
         set (obj.baseline, "xdata", xlim);
@@ -298,27 +347,23 @@
   endfor
 endfunction
 
-function update_baseline (h, d)
+function update_baseline (h, ~)
   visible = get (h, "visible");
   ydata = get (h, "ydata")(1);
 
+  ## Search axis for a bargroup that contains this baseline handle
   kids = get (get (h, "parent"), "children");
   for i = 1 : length (kids)
-    obj = get (kids (i));
+    obj = get (kids(i));
     if (strcmp (obj.type, "hggroup") && isfield (obj, "baseline")
         && obj.baseline == h)
-      ## Only alter if changed to avoid recursion of the listener functions
-      if (! strcmpi (get (kids(i), "showbaseline"), visible))
-        set (kids (i), "showbaseline", visible);
-      endif
-      if (! strcmpi (get (kids(i), "basevalue"), visible))
-        set (kids (i), "basevalue", ydata);
-      endif
+      set (obj.bargroup, "showbaseline", visible, "basevalue", ydata);
+      break;
     endif
   endfor
 endfunction
 
-function show_baseline (h, d, prop = "")
+function show_baseline (h, ~, prop = "")
   persistent recursion = false;
   
   ## Don't allow recursion
@@ -328,11 +373,8 @@
       hlist = get (h, "bargroup");
       if (strcmp (prop, "showbl"))
         showbaseline = get (h, "showbaseline");
-        for hh = hlist(:)'
-          if (hh != h)
-            set (hh, "showbaseline", showbaseline);
-          endif
-        endfor
+        hlist = hlist(hlist != h);  # remove current handle being updated
+        set (hlist, "showbaseline", showbaseline);
       elseif (strcmp (prop, "visib"))
         showbaseline = "on";
         if (all (strcmp (get (hlist, "visible"), "off")))
@@ -346,28 +388,33 @@
   endif
 endfunction
 
-function move_baseline (h, d)
-  b0 = get (h, "basevalue");
-  bl = get (h, "baseline");
+function move_baseline (h, ~)
+  persistent recursion = false;
 
-  if (get (bl, "ydata") != [b0, b0])
-    set (bl, "ydata", [b0, b0]);
-  endif
+  ## Don't allow recursion
+  if (! recursion)
+    recursion = true;
+    unwind_protect
+      b0 = get (h, "basevalue");
+      bl = get (h, "baseline");
+      set (bl, "ydata", [b0, b0]);
 
-  if (strcmpi (get (h, "barlayout"), "grouped"))
-    update_data (h, d);
+      if (strcmp (get (h, "barlayout"), "grouped"))
+        update_data (h);
+      endif
+    unwind_protect_cleanup
+      recursion = false;
+    end_unwind_protect
   endif
 endfunction
 
-function update_props (h, d)
+function update_props (h, ~)
   kids = get (h, "children");
-  set (kids, "edgecolor", get (h, "edgecolor"),
-             "linewidth", get (h, "linewidth"),
-             "linestyle", get (h, "linestyle"),
-             "facecolor", get (h, "facecolor"));
+  set (kids, {"edgecolor", "linewidth", "linestyle", "facecolor"},
+       get (h, {"edgecolor", "linewidth", "linestyle", "facecolor"}));
 endfunction
 
-function update_data (h, d)
+function update_data (h, ~)
   persistent recursion = false;
 
   ## Don't allow recursion
@@ -376,23 +423,23 @@
       recursion = true;
       hlist = get (h, "bargroup");
       x = get (h, "xdata");
-      if (!isvector (x))
+      if (! isvector (x))
         x = x(:);
       endif
-      y = [];
-      for hh = hlist(:)'
-        ytmp = get (hh, "ydata");
-        y = [y ytmp(:)];
-      endfor
+      ydat = get (hlist, "ydata");
+      if (iscell (ydat))
+        y = cell2mat (ydat.');
+      else
+        y = ydat;
+      endif
 
       [xb, yb] = bar (x, y, get (h, "barwidth"), get (h, "barlayout"),
                       "basevalue", get (h, "basevalue"));
-      ny = columns (y);
-      vert = strcmpi (get (h, "horizontal"), "off");
 
-      for i = 1:ny
+      vertical = strcmp (get (h, "horizontal"), "off");
+      for i = 1:columns (y)
         hp = get (hlist(i), "children");
-        if (vert)
+        if (vertical)
           set (hp, "xdata", xb(:,:,i), "ydata", yb(:,:,i));
         else
           set (hp, "xdata", yb(:,:,i), "ydata", xb(:,:,i));
@@ -404,7 +451,7 @@
   endif
 endfunction
 
-function update_group (h, d)
+function update_group (h, ~)
   persistent recursion = false;
 
   ## Don't allow recursion
@@ -416,21 +463,10 @@
       barlayout = get (h, "barlayout");
       horizontal = get (h, "horizontal");
 
-      ## To prevent recursion, only change if modified
-      for hh = hlist(:)'
-        if (hh != h)
-          if (get (hh, "barwidth") != barwidth)
-            set (hh, "barwidth", barwidth);
-          endif
-          if (! strcmpi (get (hh, "barlayout"), barlayout))
-            set (hh, "barlayout", barlayout);
-          endif
-          if (! strcmpi (get (hh, "horizontal"), horizontal))
-            set (hh, "horizontal", horizontal);
-          endif
-        endif
-      endfor
-      update_data (h, d);
+      hlist = hlist(hlist != h);  # remove current handle being updated
+      set (hlist, "barwidth", barwidth, "barlayout", barlayout,
+                  "horizontal", horizontal);
+      update_data (h);
     unwind_protect_cleanup
       recursion = false;
     end_unwind_protect