## Copyright (C) 2005-2012 John W. Eaton
##
## This file is part of Octave.
##
## Octave is free software; you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 3 of the License, or (at
## your option) any later version.
##
## Octave is distributed in the hope that it will be useful, but
## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
## General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with Octave; see the file COPYING.  If not, see
## <http://www.gnu.org/licenses/>.

## -*- texinfo -*-
## @deftypefn {Function File} {} __go_draw_axes__ (@var{h}, @var{plot_stream}, @var{enhanced}, @var{mono})
## Undocumented internal function.
## @end deftypefn

## Author: jwe

function __go_draw_axes__ (h, plot_stream, enhanced, mono,
                           bg_is_set, fg_is_set, hlgnd)

  if (nargin >= 4 && nargin <= 7)

    showhiddenhandles = get (0, "showhiddenhandles");
    unwind_protect
      set (0, "showhiddenhandles", "on");
      axis_obj = __get__ (h);
    unwind_protect_cleanup
      set (0, "showhiddenhandles", showhiddenhandles);
    end_unwind_protect

    parent_figure_obj = get (axis_obj.parent);
    gnuplot_term = __gnuplot_get_var__ (axis_obj.parent, "GPVAL_TERM");

    ## Set to false for plotyy axes.
    ymirror = true;
    if (isfield (axis_obj, "__plotyy_axes__"))
      if (all (ishandle (axis_obj.__plotyy_axes__)))
        ymirror = false;
      else
        h = axis_obj.__plotyy_axes__;
        h = h(ishandle (h));
        h = h(isprop (h, "__ploty_axes__"));
        rmappdata (h, "__plotyy_axes__")
      endif
    endif

    nd = __calc_dimensions__ (h);

    if (strcmp (axis_obj.dataaspectratiomode, "manual")
        && strcmp (axis_obj.xlimmode, "manual")
        && strcmp (axis_obj.ylimmode, "manual"))
      ## All can't be "manual"
      axis_obj.plotboxaspectratiomode = "auto";
    endif

    if (strcmp (axis_obj.dataaspectratiomode, "manual")
        && strcmp (axis_obj.xlimmode, "manual")
        && strcmp (axis_obj.ylimmode, "manual")
        && (nd == 2 || all (mod (axis_obj.view, 90) == 0)))
      ## FIXME - adjust plotboxaspectratio to respect other
      fpos = get (axis_obj.parent, "position");
      apos = axis_obj.position;
    endif

    pos = __actual_axis_position__ (h);

    if (strcmpi (axis_obj.dataaspectratiomode, "manual"))
      dr = axis_obj.dataaspectratio;
      if (nd == 2 || all (mod (axis_obj.view, 90) == 0))
        dr = dr(1) / dr(2);
      else
        ## FIXME - need to properly implement 3D
        dr = mean (dr(1:2)) / dr(3);
      endif
    else
      dr = 1;
    endif

    if (strcmp (axis_obj.activepositionproperty, "position"))
      if (__gnuplot_has_feature__ ("screen_coordinates_for_{lrtb}margin"))
        if (nd == 2 || all (mod (axis_obj.view, 90) == 0))
          x = [1, 1];
        else
          ## 3D plots need to be sized down to fit in the window.
          x = 1.0 ./ sqrt([2, 2.5]);
        endif
        fprintf (plot_stream, "set tmargin screen %.15g;\n",
                 pos(2)+pos(4)/2+x(2)*pos(4)/2);
        fprintf (plot_stream, "set bmargin screen %.15g;\n",
                 pos(2)+pos(4)/2-x(2)*pos(4)/2);
        fprintf (plot_stream, "set lmargin screen %.15g;\n",
                 pos(1)+pos(3)/2-x(1)*pos(3)/2);
        fprintf (plot_stream, "set rmargin screen %.15g;\n",
                 pos(1)+pos(3)/2+x(1)*pos(3)/2);
        sz_str = "";
      else
        fprintf (plot_stream, "set tmargin 0;\n");
        fprintf (plot_stream, "set bmargin 0;\n");
        fprintf (plot_stream, "set lmargin 0;\n");
        fprintf (plot_stream, "set rmargin 0;\n");

        if (nd == 3 && all (axis_obj.view == [0, 90]))
          ## FIXME -- Kludge to allow colorbar to be added to a pcolor() plot
          pos(3:4) = pos(3:4) * 1.4;
          pos(1:2) = pos(1:2) - pos(3:4) * 0.125;
        endif

        fprintf (plot_stream, "set origin %.15g, %.15g;\n", pos(1), pos(2));

        if (strcmpi (axis_obj.dataaspectratiomode, "manual"))
          sz_str = sprintf ("set size ratio %.15g", -dr);
        else
          sz_str = "set size noratio";
        endif
        sz_str = sprintf ("%s %.15g, %.15g;\n", sz_str, pos(3), pos(4));
      endif
    else ## activepositionproperty == outerposition
      fprintf (plot_stream, "unset tmargin;\n");
      fprintf (plot_stream, "unset bmargin;\n");
      fprintf (plot_stream, "unset lmargin;\n");
      fprintf (plot_stream, "unset rmargin;\n");
      fprintf (plot_stream, "set origin %g, %g;\n", pos(1:2));
      sz_str = "";
      if (strcmpi (axis_obj.dataaspectratiomode, "manual"))
        sz_str = sprintf ("ratio %g", -dr);
      else
        sz_str = "noratio";
      endif
      sz_str = sprintf ("set size %s %g, %g;\n", sz_str, pos(3:4));
    endif
    if (! isempty (sz_str))
      fputs (plot_stream, sz_str);
    endif

    ## Reset all labels, axis-labels, tick-labels, and title
    ## FIXME - We should have an function to initialize the axis.
    ##         Presently, this is dispersed in this function.
    fputs (plot_stream, "unset label;\n");
    fputs (plot_stream, "unset xtics;\n");
    fputs (plot_stream, "unset ytics;\n");
    fputs (plot_stream, "unset ztics;\n");
    fputs (plot_stream, "unset x2tics;\n");
    fputs (plot_stream, "unset x2tics;\n");

    if (! isempty (axis_obj.title))
      t = get (axis_obj.title);
      if (isempty (t.string))
        fputs (plot_stream, "unset title;\n");
      else
        [tt, f, s] = __maybe_munge_text__ (enhanced, t, "string");
        fontspec = create_fontspec (f, s, gnuplot_term);
        fprintf (plot_stream, "set title \"%s\" %s %s;\n",
                 undo_string_escapes (tt), fontspec,
                 __do_enhanced_option__ (enhanced, t));
      endif
    endif

    if (! isempty (axis_obj.xlabel))
      t = get (axis_obj.xlabel);
      angle = t.rotation;
      colorspec = get_text_colorspec (axis_obj.xcolor, mono);
      if (isempty (t.string))
        fprintf (plot_stream, "unset xlabel;\n");
        fprintf (plot_stream, "unset x2label;\n");
      else
        [tt, f, s] = __maybe_munge_text__ (enhanced, t, "string");
        fontspec = create_fontspec (f, s, gnuplot_term);
        if (strcmpi (axis_obj.xaxislocation, "top"))
          fprintf (plot_stream, "set x2label \"%s\" %s %s %s",
                   undo_string_escapes (tt), colorspec, fontspec,
                   __do_enhanced_option__ (enhanced, t));
        else
          fprintf (plot_stream, "set xlabel \"%s\" %s %s %s",
                   undo_string_escapes (tt), colorspec, fontspec,
                   __do_enhanced_option__ (enhanced, t));
        endif
        fprintf (plot_stream, " rotate by %f;\n", angle);
        if (strcmpi (axis_obj.xaxislocation, "top"))
          fprintf (plot_stream, "unset xlabel;\n");
        else
          fprintf (plot_stream, "unset x2label;\n");
        endif
      endif
    endif

    if (! isempty (axis_obj.ylabel))
      t = get (axis_obj.ylabel);
      angle = t.rotation;
      colorspec = get_text_colorspec (axis_obj.ycolor, mono);
      if (isempty (t.string))
        fprintf (plot_stream, "unset ylabel;\n");
        fprintf (plot_stream, "unset y2label;\n");
      else
        [tt, f, s] = __maybe_munge_text__ (enhanced, t, "string");
        fontspec = create_fontspec (f, s, gnuplot_term);
        if (strcmpi (axis_obj.yaxislocation, "right"))
          fprintf (plot_stream, "set y2label \"%s\" %s %s %s",
                   undo_string_escapes (tt), colorspec, fontspec,
                   __do_enhanced_option__ (enhanced, t));
        else
          fprintf (plot_stream, "set ylabel \"%s\" %s %s %s",
                   undo_string_escapes (tt), colorspec, fontspec,
                   __do_enhanced_option__ (enhanced, t));
        endif
        fprintf (plot_stream, " rotate by %f;\n", angle);
        if (strcmpi (axis_obj.yaxislocation, "right"))
          fprintf (plot_stream, "unset ylabel;\n");
        else
          fprintf (plot_stream, "unset y2label;\n");
        endif
      endif
    endif

    if (! isempty (axis_obj.zlabel))
      t = get (axis_obj.zlabel);
      angle = t.rotation;
      colorspec = get_text_colorspec (axis_obj.zcolor, mono);
      if (isempty (t.string))
        fputs (plot_stream, "unset zlabel;\n");
      else
        [tt, f, s] = __maybe_munge_text__ (enhanced, t, "string");
        fontspec = create_fontspec (f, s, gnuplot_term);
        fprintf (plot_stream, "set zlabel \"%s\" %s %s %s",
                 undo_string_escapes (tt), colorspec, fontspec,
                 __do_enhanced_option__ (enhanced, t));
        fprintf (plot_stream, " rotate by %f;\n", angle);
      endif
    endif

    if (strcmpi (axis_obj.xaxislocation, "top"))
      xaxisloc = "x2";
      xaxisloc_using = "x2";
    else
      xaxisloc = "x";
      xaxisloc_using = "x1";
      if (strcmpi (axis_obj.xaxislocation, "zero"))
        fputs (plot_stream, "set xzeroaxis;\n");
      endif
    endif
    if (strcmpi (axis_obj.yaxislocation, "right"))
      yaxisloc = "y2";
      yaxisloc_using = "y2";
    else
      yaxisloc = "y";
      yaxisloc_using = "y1";
      if (strcmpi (axis_obj.yaxislocation, "zero"))
        fputs (plot_stream, "set yzeroaxis;\n");
      endif
    endif

    have_grid = false;

    if (strcmpi (axis_obj.xgrid, "on"))
      have_grid = true;
      fprintf (plot_stream, "set grid %stics;\n", xaxisloc);
    else
      fprintf (plot_stream, "set grid no%stics;\n", xaxisloc);
    endif

    if (strcmpi (axis_obj.ygrid, "on"))
      have_grid = true;
      fprintf (plot_stream, "set grid %stics;\n", yaxisloc);
    else
      fprintf (plot_stream, "set grid no%stics;\n", yaxisloc);
    endif

    if (strcmpi (axis_obj.zgrid, "on"))
      have_grid = true;
      fputs (plot_stream, "set grid ztics;\n");
    else
      fputs (plot_stream, "set grid noztics;\n");
    endif

    if (strcmpi (axis_obj.xminorgrid, "on"))
      have_grid = true;
      if (strcmp (axis_obj.xscale, "log"))
        m = 10;
      else
        m = 5;
      endif
      fprintf (plot_stream, "set m%stics %d;\n", xaxisloc, m);
      fprintf (plot_stream, "set grid m%stics;\n", xaxisloc);
    else
      fprintf (plot_stream, "set grid nom%stics;\n", xaxisloc);
    endif

    if (strcmpi (axis_obj.yminorgrid, "on"))
      have_grid = true;
      if (strcmp (axis_obj.yscale, "log"))
        m = 10;
      else
        m = 5;
      endif
      fprintf (plot_stream, "set m%stics %d;\n", yaxisloc, m);
      fprintf (plot_stream, "set grid m%stics;\n", yaxisloc);
    else
      fprintf (plot_stream, "set grid nom%stics;\n", yaxisloc);
    endif

    if (strcmpi (axis_obj.zminorgrid, "on"))
      have_grid = true;
      if (strcmp (axis_obj.zscale, "log"))
        m = 10;
      else
        m = 5;
      endif
      fprintf (plot_stream, "set mztics %d;\n", m);
      fputs (plot_stream, "set grid mztics;\n");
    else
      fputs (plot_stream, "set grid nomztics;\n");
    endif

    ## The grid front/back/layerdefault option also controls the
    ## appearance of tics, so it is used even if the grid is absent.
    if (strcmpi (axis_obj.layer, "top"))
      fputs (plot_stream, "set grid front;\n");
      fputs (plot_stream, "set border front;\n");
    else
      fputs (plot_stream, "set grid layerdefault;\n");
      ## FIXME -- the gnuplot help says that "layerdefault" should work
      ## for set border too, but it fails for me with gnuplot 4.2.5.  So
      ## use "back" instead.
      fputs (plot_stream, "set border back;\n");
    endif

    fprintf (plot_stream, "set grid linewidth %f, linewidth %f;\n",
             axis_obj.linewidth, axis_obj.linewidth);

    if (! have_grid)
      fputs (plot_stream, "unset grid;\n");
    endif

    xlogscale = strcmpi (axis_obj.xscale, "log");
    ylogscale = strcmpi (axis_obj.yscale, "log");
    zlogscale = strcmpi (axis_obj.zscale, "log");

    ## Detect logscale and negative lims
    if (xlogscale && all (axis_obj.xlim < 0))
      axis_obj.xsgn = -1;
      if (strcmp (axis_obj.xdir, "reverse"))
        axis_obj.xdir = "normal";
      elseif (strcmp (axis_obj.xdir, "normal"))
        axis_obj.xdir = "reverse";
      endif
      axis_obj.xtick = -flip (axis_obj.xtick);
      axis_obj.xticklabel = flip (axis_obj.xticklabel);
      axis_obj.xlim = -flip (axis_obj.xlim);
    else
      axis_obj.xsgn = 1;
    endif
    if (ylogscale && all (axis_obj.ylim < 0))
      axis_obj.ysgn = -1;
      if (strcmp (axis_obj.ydir, "reverse"))
        axis_obj.ydir = "normal";
      elseif (strcmp (axis_obj.ydir, "normal"))
        axis_obj.ydir = "reverse";
      endif
      axis_obj.ytick = -flip (axis_obj.ytick);
      axis_obj.yticklabel = flip (axis_obj.yticklabel);
      axis_obj.ylim = -flip (axis_obj.ylim);
    else
      axis_obj.ysgn = 1;
    endif
    if (zlogscale && all (axis_obj.zlim < 0))
      axis_obj.zsgn = -1;
      if (strcmp (axis_obj.zdir, "reverse"))
        axis_obj.zdir = "normal";
      elseif (strcmp (axis_obj.zdir, "normal"))
        axis_obj.zdir = "reverse";
      endif
      axis_obj.ztick = -flip (axis_obj.ztick);
      axis_obj.zticklabel = flip (axis_obj.zticklabel);
      axis_obj.zlim = -flip (axis_obj.zlim);
    else
      axis_obj.zsgn = 1;
    endif

    xlim = axis_obj.xlim;
    ylim = axis_obj.ylim;
    zlim = axis_obj.zlim;
    clim = axis_obj.clim;

    do_tics (axis_obj, plot_stream, ymirror, mono, gnuplot_term);

    fputs (plot_stream, "unset logscale;\n");
    if (xlogscale)
      fprintf (plot_stream, "set logscale %s;\n", xaxisloc);
    endif
    if (ylogscale)
      fprintf (plot_stream, "set logscale %s;\n", yaxisloc);
    endif
    if (zlogscale)
      fputs (plot_stream, "set logscale z;\n");
    endif

    xautoscale = strcmpi (axis_obj.xlimmode, "auto");
    yautoscale = strcmpi (axis_obj.ylimmode, "auto");
    zautoscale = strcmpi (axis_obj.zlimmode, "auto");
    cautoscale = strcmpi (axis_obj.climmode, "auto");
    cdatadirect = false;
    truecolor = false;

    fputs (plot_stream, "set clip two;\n");

    kids = axis_obj.children;
    ## Remove the axis labels and title from the children, and
    ## preserved the original order.
    [jnk, k] = setdiff (kids, [axis_obj.xlabel; axis_obj.ylabel; ...
                               axis_obj.zlabel; axis_obj.title]);
    kids = kids (sort (k));

    if (nd == 3)
      fputs (plot_stream, "set parametric;\n");
      fputs (plot_stream, "set style data lines;\n");
      fputs (plot_stream, "set surface;\n");
      fputs (plot_stream, "unset contour;\n");
    endif

    data_idx = 0;
    data = cell ();
    is_image_data = [];
    hidden_removal = NaN;
    view_map = false;

    if (! cautoscale && clim(1) == clim(2))
      clim(2)++;
    endif
    addedcmap = [];

    ximg_data = {};
    ximg_data_idx = 0;

    while (! isempty (kids))

      obj = get (kids(end));

      if (isfield (obj, "units"))
        units = obj.units;
        unwind_protect
          set (kids(end), "units", "data");
          obj = get (kids(end));
        unwind_protect_cleanup
          set (kids(end), "units", units);
        end_unwind_protect
      endif
      kids = kids(1:(end-1));

      if (strcmpi (obj.visible, "off"))
        continue;
      endif

      if (xlogscale && isfield (obj, "xdata"))
        obj.xdata = axis_obj.xsgn * obj.xdata;
        obj.xdata(obj.xdata<=0) = NaN;
      endif
      if (ylogscale && isfield (obj, "ydata"))
        obj.ydata = axis_obj.ysgn * obj.ydata;
        obj.ydata(obj.ydata<=0) = NaN;
      endif
      if (zlogscale && isfield (obj, "zdata"))
        obj.zdata = axis_obj.zsgn * obj.zdata;
        obj.zdata(obj.zdata<=0) = NaN;
      endif

      ## Check for facecolor interpolation for surfaces.
      doing_interp_color = ...
         isfield (obj, "facecolor") && strncmp (obj.facecolor, "interp", 6);

      switch (obj.type)
        case "image"
          img_data = obj.cdata;
          img_xdata = obj.xdata;
          img_ydata = obj.ydata;

          if (ndims (img_data) == 3)
            truecolor = true;
          elseif (strcmpi (obj.cdatamapping, "direct"))
            cdatadirect = true;
          endif
          data_idx++;
          is_image_data(data_idx) = true;
          parametric(data_idx) = false;
          have_cdata(data_idx) = false;
          have_3d_patch(data_idx) = false;

          if (img_xdata(2) < img_xdata(1))
            img_xdata = img_xdata(2:-1:1);
            img_data = img_data(:,end:-1:1,:);
          elseif (img_xdata(1) == img_xdata(2))
            img_xdata = img_xdata(1) + [0, size(img_data,2)-1];
          endif
          if (img_ydata(2) < img_ydata(1))
            img_ydata = img_ydata(2:-1:1);
            img_data = img_data(end:-1:1,:,:);
          elseif (img_ydata(1) == img_ydata(2))
            img_ydata = img_ydata(1) + [0, size(img_data,1)-1];
          endif

          [y_dim, x_dim] = size (img_data(:,:,1));
          if (x_dim > 1)
            dx = abs (img_xdata(2)-img_xdata(1))/(x_dim-1);
          else
            x_dim = 2;
            img_data = [img_data, img_data];
            dx = abs (img_xdata(2)-img_xdata(1));
          endif
          if (y_dim > 1)
            dy = abs (img_ydata(2)-img_ydata(1))/(y_dim-1);
          else
            y_dim = 2;
            img_data = [img_data; img_data];
            dy = abs (img_ydata(2)-img_ydata(1));
          endif

          x_origin = min (img_xdata);
          y_origin = min (img_ydata);

          if (ndims (img_data) == 3)
            data{data_idx} = permute (img_data, [3, 1, 2])(:);
            format = "1:2:3";
            imagetype = "rgbimage";
          else
            data{data_idx} = img_data(:);
            format = "1";
            imagetype = "image";
          endif

          titlespec{data_idx} = "title \"\"";
          usingclause{data_idx} = sprintf ("binary array=%dx%d scan=yx origin=(%.15g,%.15g) dx=%.15g dy=%.15g using %s",
              x_dim, y_dim, x_origin, y_origin, dx, dy, format);
          withclause{data_idx} = sprintf ("with %s;", imagetype);

        case "line"
          if (strncmp (obj.linestyle, "none", 4)
              && (! isfield (obj, "marker")
                  || (isfield (obj, "marker")
                      && strncmp (obj.marker, "none", 4))))
            continue;
          endif
          data_idx++;
          is_image_data(data_idx) = false;
          parametric(data_idx) = true;
          have_cdata(data_idx) = false;
          have_3d_patch(data_idx) = false;
          if (isempty (obj.displayname))
            titlespec{data_idx} = "title \"\"";
          else
            tmp = undo_string_escapes (__maybe_munge_text__ (enhanced, obj, "displayname"));
            titlespec{data_idx} = cstrcat ("title \"", tmp, "\"");
          endif
          usingclause{data_idx} = sprintf ("record=%d", numel (obj.xdata));
          errbars = "";
          if (nd == 3)
            xdat = obj.xdata(:);
            ydat = obj.ydata(:);
            if (! isempty (obj.zdata))
              zdat = obj.zdata(:);
            else
              zdat = zeros (size (xdat));
            endif
            data{data_idx} = [xdat, ydat, zdat]';
            usingclause{data_idx} = sprintf ("record=%d using ($1):($2):($3)", numel (xdat));
            ## fputs (plot_stream, "set parametric;\n");
          else
            xdat = obj.xdata(:);
            ydat = obj.ydata(:);
            data{data_idx} = [xdat, ydat]';
            usingclause{data_idx} = sprintf ("record=%d using ($1):($2) axes %s%s",
                                            rows(xdat), xaxisloc_using, yaxisloc_using);
          endif

          style = do_linestyle_command (obj, obj.color, data_idx, mono,
                                        plot_stream, errbars);

          withclause{data_idx} = sprintf ("with %s linestyle %d",
                                          style{1}, data_idx);

          if (length (style) > 1)
            data_idx++;
            is_image_data(data_idx) = is_image_data(data_idx - 1);
            parametric(data_idx) = parametric(data_idx - 1);
            have_cdata(data_idx) = have_cdata(data_idx - 1);
            have_3d_patch(data_idx) = have_3d_patch(data_idx - 1);
            titlespec{data_idx} = "title \"\"";
            usingclause{data_idx} = usingclause{data_idx - 1};
            data{data_idx} = data{data_idx - 1};
            withclause{data_idx} = sprintf ("with %s linestyle %d",
                                          style{2}, data_idx);
          endif
          if (length (style) > 2)
            data_idx++;
            is_image_data(data_idx) = is_image_data(data_idx - 1);
            parametric(data_idx) = parametric(data_idx - 1);
            have_cdata(data_idx) = have_cdata(data_idx - 1);
            have_3d_patch(data_idx) = have_3d_patch(data_idx - 1);
            titlespec{data_idx} = "title \"\"";
            usingclause{data_idx} = usingclause{data_idx - 1};
            data{data_idx} = data{data_idx - 1};
            withclause{data_idx} = sprintf ("with %s linestyle %d",
                                          style{3}, data_idx);
          endif

       case "patch"
         cmap = parent_figure_obj.colormap;
         [nr, nc] = size (obj.xdata);

         if (! isempty (obj.cdata))
           cdat = obj.cdata;
           if (strcmpi (obj.cdatamapping, "direct"))
             cdatadirect = true;
           endif
         else
           cdat = [];
         endif

         data_3d_idx = NaN;
         for i = 1:nc
           xcol = obj.xdata(:,i);
           ycol = obj.ydata(:,i);
           if (nd == 3)
             if (! isempty (obj.zdata))
               zcol = obj.zdata(:,i);
             else
               zcol = zeros (size (xcol));
             endif
           endif

           if (! isnan (xcol) && ! isnan (ycol))
             ## Is the patch closed or not
             if (strncmp (obj.facecolor, "none", 4))
               hidden_removal = false;
             else

               if (isnan (hidden_removal))
                 hidden_removal = true;
               endif
               if (nd == 3)
                 if (numel (xcol) > 3)
                   error ("__go_draw_axes__: gnuplot (as of v4.2) only supports 3D filled triangular patches");
                 else
                   if (isnan (data_3d_idx))
                     data_idx++;
                     data_3d_idx = data_idx;
                     is_image_data(data_idx) = false;
                     parametric(data_idx) = false;
                     have_cdata(data_idx) = true;
                     have_3d_patch(data_idx) = true;
                     withclause{data_3d_idx} = sprintf ("with pm3d");
                     usingclause{data_3d_idx} =  "using 1:2:3:4";
                     data{data_3d_idx} = [];
                   endif
                   local_idx = data_3d_idx;
                   ccdat = NaN;
                 endif
               else
                 data_idx++;
                 local_idx = data_idx;
                 is_image_data(data_idx) = false;
                 parametric(data_idx) = false;
                 have_cdata(data_idx) = false;
                 have_3d_patch(data_idx) = false;
               endif

               if (i > 1 || isempty (obj.displayname))
                 titlespec{local_idx} = "title \"\"";
               else
                 tmp = undo_string_escapes (__maybe_munge_text__ (enhanced, obj, "displayname"));
                 titlespec{local_idx} = cstrcat ("title \"", tmp, "\"");
               endif
               if (isfield (obj, "facecolor"))
                 if ((strncmp (obj.facecolor, "flat", 4)
                     || strncmp (obj.facecolor, "interp", 6))
                     && isfield (obj, "cdata"))
                   if (ndims (obj.cdata) == 2
                       && (size (obj.cdata, 2) == nc
                           && (size (obj.cdata, 1) == 1
                               || size (obj.cdata, 1) == 3)))
                     ccol = cdat (:, i);
                   elseif (ndims (obj.cdata) == 2
                       && (size (obj.cdata, 1) == nc
                           && (size (obj.cdata, 2) == 1
                               || size (obj.cdata, 2) == 3)))
                     ccol = cdat (i, :);
                   elseif (ndims (obj.cdata) == 3)
                     ccol = permute (cdat (:, i, :), [1, 3, 2]);
                   else
                     ccol = cdat;
                   endif
                   if (strncmp (obj.facecolor, "flat", 4))
                     if (isequal (size (ccol), [1, 3]))
                       ## RGB Triplet
                       color = ccol;
                     elseif (nd == 3 && numel (xcol) == 3)
                       ccdat = ccol;
                     else
                       if (cdatadirect)
                         r = round (ccol);
                       else
                         r = 1 + round ((size (cmap, 1) - 1)
                                        * (ccol - clim(1))/(clim(2) - clim(1)));
                       endif
                       r = max (1, min (r, size (cmap, 1)));
                       color = cmap(r, :);
                     endif
                   elseif (strncmp (obj.facecolor, "interp", 6))
                     if (nd == 3 && numel (xcol) == 3)
                       ccdat = ccol;
                       if (! isvector (ccdat))
                         tmp = rows(cmap) + rows(addedcmap) + ...
                              [1 : rows(ccdat)];
                         addedcmap = [addedcmap; ccdat];
                         ccdat = tmp(:);
                       else
                         ccdat = ccdat(:);
                       endif
                     else
                       if (sum (diff (ccol)))
                         warning ("\"interp\" not supported, using 1st entry of cdata");
                       endif
                       if (cdatadirect)
                         r = round (ccol);
                       else
                         r = 1 + round ((size (cmap, 1) - 1)
                                        * (ccol - clim(1))/(clim(2) - clim(1)));
                       endif
                       r = max (1, min (r, size (cmap, 1)));
                       color = cmap(r(1),:);
                     endif
                   endif
                 elseif (isnumeric (obj.facecolor))
                   color = obj.facecolor;
                 else
                   color = [0, 1, 0];
                 endif
               else
                 color = [0, 1, 0];
               endif

               if (nd == 3 && numel (xcol) == 3)
                 if (isnan (ccdat))
                   ccdat = (rows (cmap) + rows(addedcmap) + 1) * ones(3, 1);
                   addedcmap = [addedcmap; reshape(color, 1, 3)];
                 endif
                 data{data_3d_idx} = [data{data_3d_idx}, ...
                                      [[xcol; xcol(end)], [ycol; ycol(end)], ...
                                      [zcol; zcol(end)], [ccdat; ccdat(end)]]'];
               else
                 if (mono)
                   colorspec = "";
                 elseif (__gnuplot_has_feature__ ("transparent_patches")
                         && isscalar (obj.facealpha))
                   colorspec = sprintf ("lc rgb \"#%02x%02x%02x\" fillstyle transparent solid %f",
                                      round (255*color), obj.facealpha);
                 else
                   colorspec = sprintf ("lc rgb \"#%02x%02x%02x\"",
                                        round (255*color));
                 endif

                 withclause{data_idx} = sprintf ("with filledcurve %s",
                                               colorspec);
                 data{data_idx} = [xcol, ycol]';
                 usingclause{data_idx} = sprintf ("record=%d using ($1):($2)",
                                                  numel (xcol));
               endif
             endif
           endif

           ## patch outline
           if (!(strncmp (obj.edgecolor, "none", 4)
                  && (strncmp (obj.marker, "none", 4)
                      || (strncmp (obj.markeredgecolor, "none", 4)
                          && strncmp (obj.markerfacecolor, "none", 4)))))

             data_idx++;
             is_image_data(data_idx) = false;
             parametric(data_idx) = false;
             have_cdata(data_idx) = false;
             have_3d_patch(data_idx) = false;
             titlespec{data_idx} = "title \"\"";
             usingclause{data_idx} = sprintf ("record=%d", numel (obj.xdata));

             if (isfield (obj, "markersize"))
               mdat = obj.markersize / 3;
             endif

             if (isfield (obj, "edgecolor"))
               ## FIXME
               ## This is the wrong thing to do as edgecolor, markeredgecolor
               ## and markerfacecolor can have different values and we should
               ## treat them seperately. However, the below allow the scatter
               ## functions to work as expected, where only one of these values
               ## is set
               if (strncmp (obj.edgecolor, "none", 4))
                 if (strncmp (obj.markeredgecolor, "none", 4))
                   ec = obj.markerfacecolor;
                 else
                   ec = obj.markeredgecolor;
                 endif
               else
                 ec = obj.edgecolor;
               endif

               if ((strncmp (ec, "flat", 4)
                    || strncmp (ec, "interp", 6))
                   && isfield (obj, "cdata"))
                 if (ndims (obj.cdata) == 2
                     && (size (obj.cdata, 2) == nc
                         && (size (obj.cdata, 1) == 1
                             || size (obj.cdata, 1) == 3)))
                   ccol = cdat (:, i);
                 elseif (ndims (obj.cdata) == 2
                         && (size (obj.cdata, 1) == nc
                             && (size (obj.cdata, 2) == 1
                                 || size (obj.cdata, 2) == 3)))
                   ccol = cdat (i, :);
                 elseif (ndims (obj.cdata) == 3)
                   ccol = permute (cdat (:, i, :), [1, 3, 2]);
                 else
                   ccol = cdat;
                 endif
                 if (strncmp (ec, "flat", 4))
                   if (numel(ccol) == 3)
                     color = ccol;
                   else
                     if (isscalar (ccol))
                       ccol = repmat(ccol, numel (xcol), 1);
                     endif
                     color = "flat";
                     have_cdata(data_idx) = true;
                   endif
                 elseif (strncmp (ec, "interp", 6))
                   if (numel(ccol) == 3)
                     warning ("\"interp\" not supported, using 1st entry of cdata");
                     color = ccol(1,:);
                   else
                     if (isscalar (ccol))
                       ccol = repmat(ccol, numel (xcol), 1);
                     endif
                     color = "interp";
                     have_cdata(data_idx) = true;
                   endif
                 endif
               elseif (isnumeric (ec))
                 color = ec;
               else
                 color = [0, 0, 0];
               endif
             else
               color = [0, 0, 0];
             endif

             if (isfield (obj, "linestyle"))
               switch (obj.linestyle)
                 case "-"
                   lt = "lt 1";
                 case "--"
                   lt = "lt 2";
                 case ":"
                   lt = "lt 3";
                 case "-."
                   lt = "lt 6";
                 case "none"
                   lt = "";
                 otherwise
                   lt = "";
               endswitch
             else
               lt = "";
             endif

             if (isfield (obj, "linewidth"))
               lw = sprintf("linewidth %f", obj.linewidth);
             else
               lw  = "";
             endif

             [pt, pt2, obj] = gnuplot_pointtype (obj);
             if (! isempty (pt))
               pt = sprintf ("pointtype %s", pt);
             endif
             if (! isempty (pt2))
               pt2 = sprintf ("pointtype %s", pt2);
             endif

             if (mono)
               colorspec = "";
             else
               if (ischar (color))
                 colorspec = "palette";
               else
                 colorspec = sprintf ("lc rgb \"#%02x%02x%02x\"",
                                      round (255*color));
               endif
             endif

             sidx = 1;
             if (isempty (lt))
               style = "";
             else
               style = "lines";
             endif
             tmpwith = {};

             facesame = true;
             if (! isequal (pt, pt2) && isfield (obj, "markerfacecolor")
                 && !strncmp (obj.markerfacecolor, "none", 4))
               if (strncmp (obj.markerfacecolor, "auto", 4)
                   || ! isnumeric (obj.markerfacecolor)
                   || (isnumeric (obj.markerfacecolor)
                       && isequal (color, obj.markerfacecolor)))
                 style = strcat (style, "points");
                 if (isfield (obj, "markersize"))
                   if (length (mdat) == nc)
                     m = mdat(i);
                   else
                     m = mdat;
                   endif
                   ps = sprintf("pointsize %f", m / 3);
                 else
                   ps = "";
                 endif

                 tmpwith{sidx} = sprintf ("with %s %s %s %s %s %s",
                                          style, lw, pt2, lt, ps,
                                          colorspec);
               else
                 facesame = false;
                 if (! isempty (style))
                   tmpwith{sidx} = sprintf ("with %s %s %s %s",
                                            style, lw, lt,
                                            colorspec);
                   sidx ++;
                 endif
                 if (isnumeric (obj.markerfacecolor) && ! mono)
                   colorspec = sprintf ("lc rgb \"#%02x%02x%02x\"",
                                        round (255*obj.markerfacecolor));
                 endif
                 style = "points";
                 if (isfield (obj, "markersize"))
                   if (length (mdat) == nc)
                     m = mdat(i);
                   else
                     m = mdat;
                   endif
                   ps = sprintf("pointsize %f", m / 3);
                 else
                   ps = "";
                 endif
                 tmpwith{sidx} = sprintf ("with %s %s %s %s %s %s",
                                          style, lw, pt2, lt, ps,
                                          colorspec);
               endif
             endif

             if (isfield (obj, "markeredgecolor")
                 && !strncmp (obj.markeredgecolor, "none", 4))
               if (facesame && !isempty (pt)
                   && (strncmp (obj.markeredgecolor, "auto", 4)
                       || ! isnumeric (obj.markeredgecolor)
                       || (isnumeric (obj.markeredgecolor)
                           && isequal (color, obj.markeredgecolor))))
                 if (sidx == 1 && ((length (style) == 5
                          && strncmp (style, "lines", 5))
                         || isempty (style)))
                   style = strcat (style, "points");
                   if (isfield (obj, "markersize"))
                     if (length (mdat) == nc)
                       m = mdat(i);
                     else
                       m = mdat;
                     endif
                     ps = sprintf("pointsize %f", m / 3);
                   else
                     ps = "";
                   endif
                   tmpwith{sidx} = sprintf ("with %s %s %s %s %s %s",
                                            style, lw, pt, lt, ps,
                                            colorspec);
                 endif
               else
                 if (!isempty (style))
                   if (length(tmpwith) < sidx || isempty (tmpwith{sidx}))
                     tmpwith{sidx} = sprintf ("with %s %s %s %s",
                                              style, lw, lt,
                                              colorspec);
                   endif
                   sidx ++;
                 endif

                 if (!isempty (pt))
                   if (! mono)
                     if (strncmp (obj.markeredgecolor, "auto", 4))
                       colorspec = sprintf ("lc rgb \"#%02x%02x%02x\"",
                                            round (255*color));
                     elseif (isnumeric (obj.markeredgecolor) && ! mono)
                       colorspec = sprintf ("lc rgb \"#%02x%02x%02x\"",
                                            round (255*obj.markeredgecolor));
                     endif
                   endif
                   style = "points";
                   if (isfield (obj, "markersize"))
                     if (length (mdat) == nc)
                       m = mdat(i);
                     else
                       m = mdat;
                     endif
                     ps = sprintf("pointsize %f", m / 3);
                   else
                     ps = "";
                   endif
                   tmpwith{sidx} = sprintf ("with %s %s %s %s %s %s",
                                            style, lw, pt, lt, ps,
                                            colorspec);
                 endif
               endif
             endif

             if (isempty (tmpwith))
               withclause{data_idx} = sprintf ("with %s %s %s %s %s",
                                               style, lw, pt, lt,
                                               colorspec);
             else
               withclause{data_idx} = tmpwith{1};
             endif
             if (nd == 3)
               if (ischar (color))
                 if (! isnan (xcol) && ! isnan (ycol) && ! isnan (zcol))
                   data{data_idx} = [[xcol; xcol(1)], [ycol; ycol(1)], ...
                                     [zcol; zcol(1)], [ccol; ccol(1)]]';
                 else
                   data{data_idx} = [xcol, ycol, zcol, ccol]';
                 endif
                 usingclause{data_idx} = sprintf ("record=%d using ($1):($2):($3):($4)", columns (data{data_idx}));
               else
                 if (! isnan (xcol) && ! isnan (ycol) && ! isnan (zcol))
                   data{data_idx} = [[xcol; xcol(1)], [ycol; ycol(1)], ...
                                     [zcol; zcol(1)]]';
                 else
                   data{data_idx} = [xcol, ycol, zcol]';
                 endif
                 usingclause{data_idx} = sprintf ("record=%d using ($1):($2):($3)", columns (data{data_idx}));
               endif
             else
               if (ischar (color))
                 if (! isnan (xcol) && ! isnan (ycol))
                   data{data_idx} = [[xcol; xcol(1)], [ycol; ycol(1)], ...
                                     [ccol; ccol(1)]]';
                 else
                   data{data_idx} = [xcol, ycol, ccol]';
                 endif
                 usingclause{data_idx} = sprintf ("record=%d using ($1):($2):($3)", columns (data{data_idx}));
               else
                 if (! isnan (xcol) && ! isnan (ycol))
                   data{data_idx} = [[xcol; xcol(1)], [ycol; ycol(1)]]';
                 else
                   data{data_idx} = [xcol, ycol]';
                 endif
                 usingclause{data_idx} = sprintf ("record=%d using ($1):($2)", columns (data{data_idx}));
               endif
             endif

             if (length (tmpwith) > 1)
               data_idx++;
               is_image_data(data_idx) = is_image_data(data_idx - 1);
               parametric(data_idx) = parametric(data_idx - 1);
               have_cdata(data_idx) = have_cdata(data_idx - 1);
               have_3d_patch(data_idx) = have_3d_patch(data_idx - 1);
               titlespec{data_idx} = "title \"\"";
               usingclause{data_idx} = usingclause{data_idx - 1};
               data{data_idx} = data{data_idx - 1};
               withclause{data_idx} = tmpwith{2};
             endif
             if (length (tmpwith) > 2)
               data_idx++;
               is_image_data(data_idx) = is_image_data(data_idx - 1);
               parametric(data_idx) = parametric(data_idx - 1);
               have_cdata(data_idx) = have_cdata(data_idx - 1);
               have_3d_patch(data_idx) = have_3d_patch(data_idx - 1);
               titlespec{data_idx} = "title \"\"";
               usingclause{data_idx} = usingclause{data_idx - 1};
               data{data_idx} = data{data_idx - 1};
               withclause{data_idx} = tmpwith{3};
             endif
           endif
         endfor

        case "surface"
          view_map = true;
          if (! (strncmp (obj.edgecolor, "none", 4)
                 && strncmp (obj.facecolor, "none", 4)))
            data_idx++;
            is_image_data(data_idx) = false;
            parametric(data_idx) = false;
            have_cdata(data_idx) = true;
            have_3d_patch(data_idx) = false;
            style = do_linestyle_command (obj, obj.edgecolor,
                                          data_idx, mono,
                                          plot_stream);

            if (isempty (obj.displayname))
              titlespec{data_idx} = "title \"\"";
            else
              tmp = undo_string_escapes (__maybe_munge_text__ (enhanced, obj, "displayname"));
              titlespec{data_idx} = cstrcat ("title \"", tmp, "\"");
            endif
            withclause{data_idx} = sprintf ("with pm3d linestyle %d",
                                            data_idx);
            withpm3d = true;
            pm3didx = data_idx;

            xdat = obj.xdata;
            ydat = obj.ydata;
            zdat = obj.zdata;
            cdat = obj.cdata;

            err = false;
            if (! size_equal(zdat, cdat))
              err = true;
            endif
            if (isvector (xdat) && isvector (ydat) && ismatrix (zdat))
              if (rows (zdat) == length (ydat)
                  && columns (zdat) == length (xdat))
                [xdat, ydat] = meshgrid (xdat, ydat);
              else
                err = true;
              endif
            elseif (ismatrix (xdat) && ismatrix (ydat) && ismatrix (zdat))
              if (! size_equal (xdat, ydat, zdat))
                err = true;
              endif
            else
              err = true;
            endif
            if (err)
              error ("__go_draw_axes__: invalid grid data");
            endif
            xlen = columns (zdat);
            ylen = rows (zdat);
            if (xlen == columns (xdat) && xlen == columns (ydat)
                && ylen == rows (xdat) && ylen == rows (ydat))
              len = 4 * xlen;
              zz = zeros (ylen, len);
              k = 1;
              for kk = 1:4:len
                zz(:,kk)   = xdat(:,k);
                zz(:,kk+1) = ydat(:,k);
                zz(:,kk+2) = zdat(:,k);
                zz(:,kk+3) = cdat(:,k);
                k++;
              endfor
              data{data_idx} = zz.';
            endif

            if (doing_interp_color)
              interp_str = "interpolate 0, 0";
            else
              ## No interpolation of facecolors.
              interp_str = "";
            endif
            usingclause{data_idx} = sprintf ("record=%dx%d using ($1):($2):($3):($4)", ylen, xlen);

            flat_interp_face = (strncmp (obj.facecolor, "flat", 4)
                                || strncmp (obj.facecolor, "interp", 6));
            flat_interp_edge = (strncmp (obj.edgecolor, "flat", 4)
                                || strncmp (obj.edgecolor, "interp", 6));

            facecolor_none_or_white = (strncmp (obj.facecolor, "none", 4)
                                       || (isnumeric (obj.facecolor)
                                           && all (obj.facecolor == 1)));
            hidden_removal = false;
            fputs (plot_stream, "set style increment default;\n");
            if (flat_interp_edge && facecolor_none_or_white)
              withpm3d = false;
              withclause{data_idx} = sprintf ("with %s palette", style {1});
              fputs (plot_stream, "unset pm3d\n");
              if (all (obj.facecolor == 1))
                hidden_removal = true;
              endif
            elseif (facecolor_none_or_white)
              if (all (obj.facecolor == 1))
                hidden_removal = true;
              endif
              fputs(plot_stream,"unset pm3d;\n");
              fputs(plot_stream,"set style increment user;\n");
              withpm3d = false;
              withclause{data_idx} = sprintf("with %s linestyle %d",
                                             style{1}, data_idx);
              fputs (plot_stream, "unset pm3d\n");
            endif

            if (doing_interp_color)
              ## "depthorder" interferes with interpolation of colors.
              dord = "scansautomatic";
            else
              dord = "depthorder";
            endif

            if (flat_interp_face && strncmp (obj.edgecolor, "flat", 4))
              fprintf (plot_stream, "set pm3d explicit at s %s %s corners2color c3;\n",
                       interp_str, dord);
            elseif (!facecolor_none_or_white)
              if (strncmp (obj.edgecolor, "none", 4))
                if (__gnuplot_has_feature__ ("transparent_surface")
                    && isscalar (obj.facealpha))
                  fprintf (plot_stream,
                           "set style fill transparent solid %f;\n",
                           obj.facealpha);
                endif
                fprintf (plot_stream, "set pm3d explicit at s %s corners2color c3;\n",
                         interp_str, dord);
              else
                fprintf (plot_stream, "set pm3d explicit at s hidden3d %d %s %s corners2color c3;\n",
                         data_idx, interp_str, dord);

                if (__gnuplot_has_feature__ ("transparent_surface")
                    && isscalar (obj.facealpha))
                  fprintf (plot_stream,
                           "set style fill transparent solid %f;\n",
                           obj.facealpha);
                endif
              endif
            endif

            zz = [];
            if (length (style) > 1)
              len = 3 * xlen;
              zz = zeros (ylen, len);
              k = 1;
              for kk = 1:3:len
                zz(:,kk)   = xdat(:,k);
                zz(:,kk+1) = ydat(:,k);
                zz(:,kk+2) = zdat(:,k);
                k++;
              endfor
              zz = zz.';

              data_idx++;
              is_image_data(data_idx) = is_image_data(data_idx - 1);
              parametric(data_idx) = parametric(data_idx - 1);
              have_cdata(data_idx) = false;
              have_3d_patch(data_idx) = have_3d_patch(data_idx - 1);
              titlespec{data_idx} = "title \"\"";
              usingclause{data_idx} = sprintf ("record=%dx%d using ($1):($2):($3)", ylen, xlen);
              data{data_idx} = zz;
              withclause{data_idx} = sprintf ("with %s linestyle %d",
                                              style{2}, data_idx);

            endif
            if (length (style) > 2)
              data_idx++;
              is_image_data(data_idx) = is_image_data(data_idx - 1);
              parametric(data_idx) = parametric(data_idx - 1);
              have_cdata(data_idx) = false;
              have_3d_patch(data_idx) = have_3d_patch(data_idx - 1);
              titlespec{data_idx} = "title \"\"";
              usingclause{data_idx} = sprintf ("record=%dx%d using ($1):($2):($3)", ylen, xlen);
              data{data_idx} = zz;
              withclause{data_idx} = sprintf ("with %s linestyle %d",
                                              style{3}, data_idx);
            endif
            if (withpm3d && strncmp (style {1}, "linespoints", 11))
              if (isempty(zz))
                len = 3 * xlen;
                zz = zeros (ylen, len);
                k = 1;
                for kk = 1:3:len
                  zz(:,kk)   = xdat(:,k);
                  zz(:,kk+1) = ydat(:,k);
                  zz(:,kk+2) = zdat(:,k);
                  k++;
                endfor
                zz = zz.';
              endif
              data_idx++;
              is_image_data(data_idx) = is_image_data(data_idx - 1);
              parametric(data_idx) = parametric(data_idx - 1);
              have_cdata(data_idx) = false;
              have_3d_patch(data_idx) = have_3d_patch(data_idx - 1);
              titlespec{data_idx} = "title \"\"";
              usingclause{data_idx} = sprintf ("record=%dx%d using ($1):($2):($3)", ylen, xlen);
              data{data_idx} = zz;
              withclause{data_idx} = sprintf ("with points linestyle %d",
                                              pm3didx);
            endif
          endif

        case "text"
          [label, f, s] = __maybe_munge_text__ (enhanced, obj, "string");
          fontspec = create_fontspec (f, s, gnuplot_term);
          lpos = obj.position;
          halign = obj.horizontalalignment;
          valign = obj.verticalalignment;
          angle = obj.rotation;
          units = obj.units;
          color = obj.color;
          if (strcmpi (units, "normalized"))
            units = "graph";
          elseif (strcmp (axis_obj.yaxislocation, "right")
                  && strcmp (units, "data"))
            units = "second";
          else
            units = "";
          endif

          if (isnumeric (color))
            colorspec = get_text_colorspec (color, mono);
          endif

          if (ischar (obj.string))
            num_lines = size (obj.string, 1);
          else
            num_lines = numel (obj.string);
          endif
          switch valign
            ## Text offset in characters. This relies on gnuplot for font metrics.
            case "top"
              dy = -0.5;
            case "cap"
              dy = -0.5;
            case "middle"
              dy = 0.5 * (num_lines - 1);
            case "baseline"
              dy = 0.5 + (num_lines - 1);
            case "bottom"
              dy = 0.5 + (num_lines - 1);
          endswitch
          ## Gnuplot's Character units are different for x/y and vary with fontsize. The aspect ratio
          ## of 1:1.7 was determined by experiment to work for eps/ps/etc. For the MacOS aqua terminal
          ## a value of 2.5 is needed. However, the difference is barely noticable.
          dx_and_dy = [(-dy * sind (angle)), (dy * cosd(angle))] .* [1.7 1];

          ## FIXME - Multiline text produced the gnuplot "warning: ft_render: skipping glyph"
          if (nd == 3)
            ## This produces the desired vertical alignment in 3D.
            fprintf (plot_stream,
                     "set label \"%s\" at %s %.15e,%.15e,%.15e %s rotate by %f offset character %f,%f %s %s front %s;\n",
                     undo_string_escapes (label), units, lpos(1),
                     lpos(2), lpos(3), halign, angle, dx_and_dy, fontspec,
                     __do_enhanced_option__ (enhanced, obj), colorspec);
          else
            fprintf (plot_stream,
                     "set label \"%s\" at %s %.15e,%.15e %s rotate by %f offset character %f,%f %s %s front %s;\n",
                     undo_string_escapes (label), units,
                     lpos(1), lpos(2), halign, angle, dx_and_dy, fontspec,
                     __do_enhanced_option__ (enhanced, obj), colorspec);
          endif

        case "hggroup"
          ## Push group children into the kid list.
          if (isempty (kids))
            kids = obj.children;
          elseif (! isempty (obj.children))
            kids = [kids; obj.children];
          endif

        otherwise
          error ("__go_draw_axes__: unknown object class, %s",
                 obj.type);
      endswitch

    endwhile

    ## This is need to prevent warnings for rotations in 3D plots, while
    ## allowing colorbars with contours.
    if (nd == 2 || (data_idx > 1 && !view_map))
      fputs (plot_stream, "set pm3d implicit;\n");
    else
      fputs (plot_stream, "set pm3d explicit;\n");
    endif

    if (isnan(hidden_removal) || hidden_removal)
      fputs (plot_stream, "set hidden3d;\n");
    else
      fputs (plot_stream, "unset hidden3d;\n");
    endif

    have_data = (! (isempty (data) || all (cellfun ("isempty", data))));

    ## Note we don't use the [xy]2range of gnuplot as we don't use the
    ## dual axis plotting features of gnuplot.
    if (isempty (xlim))
      return;
    endif
    if (strcmpi (axis_obj.xdir, "reverse"))
      xdir = "reverse";
    else
      xdir = "noreverse";
    endif
    fprintf (plot_stream, "set xrange [%.15e:%.15e] %s;\n", xlim, xdir);
    if (strcmpi (axis_obj.xaxislocation, "top"))
      fprintf (plot_stream, "set x2range [%.15e:%.15e] %s;\n", xlim, xdir);
    endif

    if (isempty (ylim))
      return;
    endif
    if (strcmpi (axis_obj.ydir, "reverse"))
      ydir = "reverse";
    else
      ydir = "noreverse";
    endif
    fprintf (plot_stream, "set yrange [%.15e:%.15e] %s;\n", ylim, ydir);
    if (strcmpi (axis_obj.yaxislocation, "right"))
      fprintf (plot_stream, "set y2range [%.15e:%.15e] %s;\n", ylim, ydir);
    endif

    if (nd == 3)
      if (isempty (zlim))
        return;
      endif
      if (strcmpi (axis_obj.zdir, "reverse"))
        zdir = "reverse";
      else
        zdir = "noreverse";
      endif
      fprintf (plot_stream, "set zrange [%.15e:%.15e] %s;\n", zlim, zdir);
    endif

    cmap = parent_figure_obj.colormap;
    cmap_sz = rows(cmap);
    if (! any (isinf (clim)))
      if (truecolor || ! cdatadirect)
        if (rows(addedcmap) > 0)
          for i = 1:data_idx
            if (have_3d_patch(i))
              data{i}(end,:) = clim(2) * (data{i}(end, :) - 0.5) / cmap_sz;
             endif
          endfor
          fprintf (plot_stream, "set cbrange [%g:%g];\n", clim(1), clim(2) *
                   (cmap_sz + rows(addedcmap)) / cmap_sz);
        else
          fprintf (plot_stream, "set cbrange [%g:%g];\n", clim);
        endif
      else
        fprintf (plot_stream, "set cbrange [1:%d];\n", cmap_sz +
                 rows (addedcmap));
      endif
    endif

    if (strcmpi (axis_obj.box, "on"))
      if (nd == 3)
        fputs (plot_stream, "set border 4095;\n");
      else
        fputs (plot_stream, "set border 431;\n");
      endif
    else
      if (nd == 3)
        fputs (plot_stream, "set border 895;\n");
      elseif (! isempty (axis_obj.ytick))
        if (strcmpi (axis_obj.yaxislocation, "right"))
          fprintf (plot_stream, "unset ytics; set y2tics %s nomirror\n",
                   axis_obj.tickdir);
          if (strcmpi (axis_obj.xaxislocation, "top"))
            fprintf (plot_stream, "unset xtics; set x2tics %s nomirror\n",
                     axis_obj.tickdir);
            fputs (plot_stream, "set border 12;\n");
          elseif (strcmpi (axis_obj.xaxislocation, "bottom"))
            fprintf (plot_stream, "unset x2tics; set xtics %s nomirror\n",
                     axis_obj.tickdir);
            fputs (plot_stream, "set border 9;\n");
          else # xaxislocation == zero
            fprintf (plot_stream, "unset x2tics; set xtics %s nomirror\n",
                     axis_obj.tickdir);
            fputs (plot_stream, "set border 8;\n");
            fprintf (plot_stream, "set xzeroaxis lt -1 lw %f;\n",
                     axis_obj.linewidth);
          endif
        elseif (strcmpi (axis_obj.yaxislocation, "left"))
          fprintf (plot_stream, "unset y2tics; set ytics %s nomirror\n",
                   axis_obj.tickdir);
          if (strcmpi (axis_obj.xaxislocation, "top"))
            fprintf (plot_stream, "unset xtics; set x2tics %s nomirror\n",
                     axis_obj.tickdir);
            fputs (plot_stream, "set border 6;\n");
          elseif (strcmpi (axis_obj.xaxislocation, "bottom"))
            fprintf (plot_stream, "unset x2tics; set xtics %s nomirror\n",
                     axis_obj.tickdir);
            fputs (plot_stream, "set border 3;\n");
          else # xaxislocation == zero
            fprintf (plot_stream, "unset x2tics; set xtics %s nomirror\n",
                     axis_obj.tickdir);
            fputs (plot_stream, "set border 2;\n");
            fprintf (plot_stream, "set xzeroaxis lt -1 lw %f;\n",
                     axis_obj.linewidth);
          endif
        else # yaxislocation == zero
          fprintf (plot_stream, "unset y2tics; set ytics %s nomirror\n",
                   axis_obj.tickdir);
          if (strcmpi (axis_obj.xaxislocation, "top"))
            fprintf (plot_stream, "unset xtics; set x2tics %s nomirror\n",
                     axis_obj.tickdir);
            fputs (plot_stream, "set border 4;\n");
          elseif (strcmpi (axis_obj.xaxislocation, "bottom"))
            fprintf (plot_stream, "unset x2tics; set xtics %s nomirror\n",
                     axis_obj.tickdir);
            fputs (plot_stream, "set border 1;\n");
          else # xaxislocation == zero
            fprintf (plot_stream, "unset y2tics; set ytics %s nomirror\n",
                     axis_obj.tickdir);
            fprintf (plot_stream, "unset x2tics; set xtics %s nomirror\n",
                     axis_obj.tickdir);
            fputs (plot_stream, "unset border;\n");
            fprintf (plot_stream, "set xzeroaxis lt -1 lw %f;\n",
                     axis_obj.linewidth);
          endif
          fprintf (plot_stream, "set yzeroaxis lt -1 lw %f;\n",
                   axis_obj.linewidth);
        endif
      endif
    endif

    if (strcmpi (axis_obj.visible, "off"))
      fputs (plot_stream, "unset border; unset tics\n");
    else
      fprintf (plot_stream, "set border lw %f;\n", axis_obj.linewidth);
    endif

    if (! isempty (hlgnd) && ! isempty (hlgnd.children)
        && any (strcmpi (get (hlgnd.children, "visible"), "on")))
      if (strcmpi (hlgnd.box, "on"))
        box = "box";
      else
        box = "nobox";
      endif
      if (strcmpi (hlgnd.orientation, "vertical"))
        horzvert = "vertical";
      else
        horzvert = "horizontal";
      endif
      if (strcmpi (hlgnd.textposition, "right"))
        reverse = "reverse";
      else
        reverse = "noreverse";
      endif
      inout = "inside";
      keypos = hlgnd.location;
      if (ischar (keypos))
        keypos = lower (keypos);
        keyout = findstr (keypos, "outside");
        if (! isempty (keyout))
          inout = "outside";
          keypos = keypos(1:keyout-1);
        endif
      endif
      switch (keypos)
        case "north"
          pos = "center top";
        case "south"
          pos = "center bottom";
        case "east"
          pos = "right center";
        case "west"
          pos = "left center";
        case "northeast"
          pos = "right top";
        case "northwest"
          pos = "left top";
        case "southeast"
          pos = "right bottom";
        case "southwest"
          pos = "left bottom";
        case "best"
          pos = "";
          warning ("legend: 'Best' not yet implemented for location specifier.\n");
          ## Least conflict with data in plot.
          ## Least unused space outside plot.
        otherwise
          pos = "";
      endswitch
      if (__gnuplot_has_feature__ ("key_has_font_properties"))
        [fontname, fontsize] = get_fontname_and_size (hlgnd);
        fontspec = create_fontspec (fontname, fontsize, gnuplot_term);
      else
        fontspec = "";
      endif
      fprintf (plot_stream, "set key %s %s;\nset key %s %s %s %s;\n",
               inout, pos, box, reverse, horzvert, fontspec);
    else
      fputs (plot_stream, "unset key;\n");
    endif
    fputs (plot_stream, "set style data lines;\n");

    cmap = [cmap; addedcmap];
    cmap_sz = cmap_sz + rows(addedcmap);
    if (length(cmap) > 0)
      fprintf (plot_stream,
               "set palette positive color model RGB maxcolors %i;\n",
               cmap_sz);
      fprintf (plot_stream,
               "set palette file \"-\" binary record=%d using 1:2:3:4;\n",
               cmap_sz);
      fwrite (plot_stream, [1:cmap_sz; cmap.'], "float32");
      fwrite (plot_stream, "\n");
    endif

    fputs (plot_stream, "unset colorbox;\n");

    if (have_data)
      if (nd == 2)
        plot_cmd = "plot";
      else
        plot_cmd = "splot";
        rot_x = 90 - axis_obj.view(2);
        rot_z = axis_obj.view(1);
        while (rot_z < 0)
          rot_z += 360;
        endwhile
        fputs (plot_stream, "set ticslevel 0;\n");
        if (view_map && rot_x == 0 && rot_z == 0)
          fputs (plot_stream, "set view map;\n");
        else
          fprintf (plot_stream, "set view %.15g, %.15g;\n", rot_x, rot_z);
        endif
      endif
      if (have_3d_patch (1))
        fputs (plot_stream, "set pm3d depthorder\n");
        fprintf (plot_stream, "%s \"-\" %s %s %s \\\n", plot_cmd,
                 usingclause{1}, titlespec{1}, withclause{1});
      elseif (is_image_data (1))
        if (numel (is_image_data) > 1 && is_image_data(2))
          ## Remove terminating semicolon
          n = max (strfind (withclause{1}, ";"));
          if (! isempty(n))
            withclause{1} = withclause{1}(1:n-1);
          endif
        endif
        fprintf (plot_stream, "%s \"-\" %s %s %s \\\n", plot_cmd,
                 usingclause{1}, titlespec{1}, withclause{1});
      else
        fprintf (plot_stream, "%s \"-\" binary format='%%float64' %s %s %s \\\n", plot_cmd,
                 usingclause{1}, titlespec{1}, withclause{1});
      endif
      for i = 2:data_idx
        if (have_3d_patch (i))
          fprintf (plot_stream, ", \"-\" %s %s %s \\\n",
                   usingclause{i}, titlespec{i}, withclause{i});
        elseif (is_image_data (i))
          if (! is_image_data (i-1))
            fputs (plot_stream, "; ");
            if (bg_is_set)
              fputs (plot_stream, "unset obj 1; \\\n");
              bg_is_set = false;
            endif
            if (fg_is_set)
              fputs (plot_stream, "unset obj 2; \\\n");
              fg_is_set = false;
            endif
            if (numel (is_image_data) > i && is_image_data(i+1))
              ## Remove terminating semicolon
              n = max (strfind (withclause{i}, ";"));
              if (! isempty(n))
                withclause{i} = withclause{i}(1:n-1);
              endif
            endif
            fprintf (plot_stream, "%s \"-\" %s %s %s \\\n", plot_cmd,
                     usingclause{i}, titlespec{i}, withclause{i});
          else
            ## For consecutive images continue with the same plot command
            fprintf (plot_stream, "%s \"-\" %s %s %s \\\n", ",",
                     usingclause{i}, titlespec{i}, withclause{i});
          endif
        elseif (is_image_data (i-1))
          if (bg_is_set)
            fputs (plot_stream, "unset obj 1; \\\n");
            bg_is_set = false;
          endif
          if (fg_is_set)
            fputs (plot_stream, "unset obj 2; \\\n");
            fg_is_set = false;
          endif
          fprintf (plot_stream, "%s \"-\" binary format='%%float64' %s %s %s \\\n", plot_cmd,
                   usingclause{i}, titlespec{i}, withclause{i});
        else
          fprintf (plot_stream, ", \"-\" binary format='%%float64' %s %s %s \\\n",
                   usingclause{i}, titlespec{i}, withclause{i});
        endif
      endfor
      fputs (plot_stream, ";\n");
      for i = 1:data_idx
        if (have_3d_patch (i))
          ## Can't write 3d patch data as binary as can't plot more than
          ## a single patch at a time and have to plot all patches together
          ## so that the gnuplot depth ordering is done correctly
          for j = 1 : 4 : columns(data{i})
            if (j != 1)
              fputs (plot_stream, "\n\n");
            endif
            fprintf (plot_stream, "%.15g %.15g %.15g %.15g\n", data{i}(:,j).');
            fprintf (plot_stream, "%.15g %.15g %.15g %.15g\n\n", data{i}(:,j+1).');
            fprintf (plot_stream, "%.15g %.15g %.15g %.15g\n", data{i}(:,j+2).');
            fprintf (plot_stream, "%.15g %.15g %.15g %.15g\n", data{i}(:,j+3).');
          endfor
          fputs (plot_stream, "e\n");
        elseif (is_image_data(i))
          fwrite (plot_stream, data{i}, "float32");
        else
          __gnuplot_write_data__ (plot_stream, data{i}, nd, parametric(i),
                                  have_cdata(i));
        endif
      endfor
    else
      fputs (plot_stream, "plot \"-\";\nInf Inf\ne\n");
    endif

    ## Needed to allow mouse rotation with pcolor.
    if (view_map)
      fputs (plot_stream, "unset view;\n");
    endif

    if (bg_is_set)
      fputs (plot_stream, "unset obj 1;\n");
      bg_is_set = false;
    endif

    fflush (plot_stream);

  else
    print_usage ();
  endif

endfunction

function x = flip (x)
  if (size (x, 1) == 1)
    x = fliplr (x);
  elseif (size (x, 2) == 1 || ischar (x))
    x = flipud (x);
  else
    x = flipud (fliplr (x));
  endif
endfunction

function fontspec = create_fontspec (f, s, gp_term)
  if (strcmp (f, "*") || strcmp (gp_term, "tikz"))
    fontspec = sprintf ("font \",%d\"", s);
  else
    fontspec = sprintf ("font \"%s,%d\"", f, s);
  endif
endfunction

function style = do_linestyle_command (obj, linecolor, idx, mono,
                                       plot_stream, errbars = "")
  style = {};

  fprintf (plot_stream, "set style line %d default;\n", idx);
  fprintf (plot_stream, "set style line %d", idx);

  found_style = false;
  if (isnumeric (linecolor))
    color = linecolor;
    if (! mono)
      fprintf (plot_stream, " linecolor rgb \"#%02x%02x%02x\"",
               round (255*color));
    endif
  else
    color = [0, 0, 0];
  endif

  if (isfield (obj, "linestyle"))
    switch (obj.linestyle)
      case "-"
        lt = "1";
      case "--"
        lt = "2";
      case ":"
        lt = "3";
      case "-."
        lt = "6";
      case "none"
        lt = "";
      otherwise
        lt = "";
    endswitch

    if (! isempty (lt))
      fprintf (plot_stream, " linetype %s", lt);
    endif

  else
    lt = "";
  endif
  if (! isempty (errbars))
    found_style = true;
  endif

  if (isfield (obj, "linewidth"))
    fprintf (plot_stream, " linewidth %f", obj.linewidth);
    found_style = true;
  endif

  [pt, pt2, obj] = gnuplot_pointtype (obj);

  if (! isempty (pt))
    found_style = true;
  endif

  sidx = 1;
  if (isempty (errbars))
    if (isempty (lt))
      style {sidx} = "";
    else
      style {sidx} = "lines";
    endif

    facesame = true;
    if (! isequal (pt, pt2) && isfield (obj, "markerfacecolor")
        && !strncmp (obj.markerfacecolor, "none", 4))
      if (strncmp (obj.markerfacecolor, "auto", 4)
          || ! isnumeric (obj.markerfacecolor)
          || (isnumeric (obj.markerfacecolor)
              && isequal (color, obj.markerfacecolor)))
        if (! isempty (pt2))
          fprintf (plot_stream, " pointtype %s", pt2);
          style {sidx} = strcat (style{sidx}, "points");
        endif
        if (isfield (obj, "markersize"))
          fprintf (plot_stream, " pointsize %f", obj.markersize / 3);
        endif
      else
        facesame = false;
        if (! found_style)
          fputs (plot_stream, " default");
        endif
        fputs (plot_stream, ";\n");
        if (! isempty (style {sidx}))
          sidx ++;
          idx ++;
        else
          fputs (plot_stream, ";\n");
        endif
        fprintf (plot_stream, "set style line %d default;\n", idx);
        fprintf (plot_stream, "set style line %d", idx);
        if (isnumeric (obj.markerfacecolor) && ! mono)
          fprintf (plot_stream, " linecolor rgb \"#%02x%02x%02x\"",
                   round (255*obj.markerfacecolor));
        endif
        if (! isempty (pt2))
          style {sidx} = "points";
          fprintf (plot_stream, " pointtype %s", pt2);
        endif
        if (isfield (obj, "markersize"))
          fprintf (plot_stream, " pointsize %f", obj.markersize / 3);
        endif
      endif
    endif
    if (isfield (obj, "markeredgecolor")
        && !strncmp (obj.markeredgecolor, "none", 4))
      if (facesame && !isempty (pt)
          && (strncmp (obj.markeredgecolor, "auto", 4)
              || ! isnumeric (obj.markeredgecolor)
              || (isnumeric (obj.markeredgecolor)
                  && isequal (color, obj.markeredgecolor))))
        if (sidx == 1 && ((length (style {sidx}) == 5
            && strncmp (style {sidx}, "lines", 5)) || isempty (style {sidx})))
          if (! isempty (pt))
            style {sidx} = strcat (style{sidx}, "points");
            fprintf (plot_stream, " pointtype %s", pt);
          endif
          if (isfield (obj, "markersize"))
            fprintf (plot_stream, " pointsize %f", obj.markersize / 3);
          endif
        endif
      else
        if (! found_style)
          fputs (plot_stream, " default");
        endif
        fputs (plot_stream, ";\n");
        if (!isempty (style {sidx}))
          sidx ++;
          idx ++;
        else
          fputs (plot_stream, ";\n");
        endif
        fprintf (plot_stream, "set style line %d default;\n", idx);
        fprintf (plot_stream, "set style line %d", idx);
        if (! mono)
          if (strncmp (obj.markeredgecolor, "auto", 4))
            fprintf (plot_stream, " linecolor rgb \"#%02x%02x%02x\"",
                     round (255*color));
          elseif (isnumeric (obj.markeredgecolor) && ! mono)
            fprintf (plot_stream, " linecolor rgb \"#%02x%02x%02x\"",
                     round (255*obj.markeredgecolor));
          endif
        endif
        if (! isempty (pt))
          style {sidx} = "points";
          fprintf (plot_stream, " pointtype %s", pt);
        endif
        if (isfield (obj, "markersize"))
          fprintf (plot_stream, " pointsize %f", obj.markersize / 3);
        endif
      endif
    endif
  else
    style{1} = errbars;
    fputs (plot_stream, " pointtype 0");
  endif

  if (! found_style && isempty (style {1}))
    fputs (plot_stream, " default");
  endif

  fputs (plot_stream, ";\n");

endfunction

function [pt, pt2, obj] = gnuplot_pointtype (obj)
  if (isfield (obj, "marker"))
    switch (obj.marker)
      case "+"
        pt = pt2 = "1";
      case "o"
        pt = "6";
        pt2 = "7";
      case "*"
        pt = pt2 = "3";
      case "."
        pt = "6";
        pt2 = "7";
        if (isfield (obj, "markerfacecolor")
            || strncmp (obj.markerfacecolor, "none", 4))
          obj.markerfacecolor = "auto";
        endif
        if (isfield (obj, "markersize"))
          obj.markersize /= 3;
        else
          obj.markersize = 5;
        endif
      case "x"
        pt = pt2 = "2";
      case {"square", "s"}
        pt = "4";
        pt2 = "5";
      case {"diamond", "d"}
        pt = "12";
        pt2 = "13";
      case "^"
        pt = "8";
        pt2 = "9";
      case "v"
        pt = "10";
        pt2 = "11";
      case ">"
        ## FIXME -- should be triangle pointing right, use triangle pointing up
        pt = "8";
        pt2 = "9";
      case "<"
        ## FIXME -- should be triangle pointing left, use triangle pointing down
        pt = "10";
        pt2 = "11";
      case {"pentagram", "p"}
        ## FIXME -- should be pentagram, using pentagon
        pt = "14";
        pt2 = "15";
      case {"hexagram", "h"}
        ## FIXME -- should be 6 pt start, using "*" instead
        pt = pt2 = "3";
      case "none"
        pt = pt2 = "";
      otherwise
        pt = pt2 = "";
    endswitch
  else
    pt = pt2 = "";
  endif
endfunction

function __gnuplot_write_data__ (plot_stream, data, nd, parametric, cdata)

  ## DATA is already transposed.

  ## FIXME -- this may need to be converted to C++ for speed.

  ## Convert NA elements to normal NaN values because fprintf writes
  ## "NA" and that confuses gnuplot.
  idx = find (isna (data));
  if (any (idx))
    data(idx) = NaN;
  endif

  if (nd == 2)
    fwrite (plot_stream, data, "float64");
  elseif (nd == 3)
    if (parametric)
      fwrite (plot_stream, data, "float64");
    else
      nr = rows (data);
      if (cdata)
        for j = 1:4:nr
          fwrite (plot_stream, data(j:j+3,:), "float64");
        endfor
      else
        for j = 1:3:nr
          fwrite (plot_stream, data(j:j+2,:), "float64");
        endfor
      endif
    endif
  endif

endfunction

function do_tics (obj, plot_stream, ymirror, mono, gnuplot_term)

  obj.xticklabel = ticklabel_to_cell (obj.xticklabel);
  obj.yticklabel = ticklabel_to_cell (obj.yticklabel);
  obj.zticklabel = ticklabel_to_cell (obj.zticklabel);

  if (strcmp (obj.xminorgrid, "on"))
    obj.xminortick = "on";
  endif
  if (strcmp (obj.yminorgrid, "on"))
    obj.yminortick = "on";
  endif
  if (strcmp (obj.zminorgrid, "on"))
    obj.zminortick = "on";
  endif

  [fontname, fontsize] = get_fontname_and_size (obj);
  fontspec = create_fontspec (fontname, fontsize, gnuplot_term);

  ## A Gnuplot tic scale of 69 is equivalent to Octave's 0.5.
  ticklength = sprintf ("scale %4.1f", (69/0.5)*obj.ticklength(1));

  if (strcmpi (obj.xaxislocation, "top"))
    do_tics_1 (obj.xtickmode, obj.xtick, obj.xminortick, obj.xticklabelmode,
               obj.xticklabel, obj.xcolor, "x2", plot_stream, true, mono,
               "border", obj.tickdir, ticklength, fontname, fontspec,
               obj.interpreter, obj.xscale, obj.xsgn, gnuplot_term);
    do_tics_1 ("manual", [], "off", obj.xticklabelmode, obj.xticklabel,
               obj.xcolor, "x", plot_stream, true, mono, "border",
               "", "", fontname, fontspec, obj.interpreter, obj.xscale,
               obj.xsgn, gnuplot_term);
  elseif (strcmpi (obj.xaxislocation, "zero"))
    do_tics_1 (obj.xtickmode, obj.xtick, obj.xminortick, obj.xticklabelmode,
               obj.xticklabel, obj.xcolor, "x", plot_stream, true, mono,
               "axis", obj.tickdir, ticklength, fontname, fontspec,
               obj.interpreter, obj.xscale, obj.xsgn, gnuplot_term);
    do_tics_1 ("manual", [], "off", obj.xticklabelmode, obj.xticklabel,
               obj.xcolor, "x2", plot_stream, true, mono, "axis",
               "", "", fontname, fontspec, obj.interpreter, obj.xscale,
               obj.xsgn, gnuplot_term);
  else
    do_tics_1 (obj.xtickmode, obj.xtick, obj.xminortick, obj.xticklabelmode,
               obj.xticklabel, obj.xcolor, "x", plot_stream, true, mono,
               "border", obj.tickdir, ticklength, fontname, fontspec,
               obj.interpreter, obj.xscale, obj.xsgn, gnuplot_term);
    do_tics_1 ("manual", [], "off", obj.xticklabelmode, obj.xticklabel,
               obj.xcolor, "x2", plot_stream, true, mono, "border",
               "", "", fontname, fontspec, obj.interpreter, obj.xscale,
               obj.xsgn, gnuplot_term);
  endif
  if (strcmpi (obj.yaxislocation, "right"))
    do_tics_1 (obj.ytickmode, obj.ytick, obj.yminortick, obj.yticklabelmode,
               obj.yticklabel, obj.ycolor, "y2", plot_stream, ymirror, mono,
               "border", obj.tickdir, ticklength, fontname, fontspec,
               obj.interpreter, obj.yscale, obj.ysgn, gnuplot_term);
    do_tics_1 ("manual", [], "off", obj.yticklabelmode, obj.yticklabel,
               obj.ycolor, "y", plot_stream, ymirror, mono, "border",
               "", "", fontname, fontspec, obj.interpreter, obj.yscale,
               obj.ysgn, gnuplot_term);
  elseif (strcmpi (obj.yaxislocation, "zero"))
    do_tics_1 (obj.ytickmode, obj.ytick, obj.yminortick, obj.yticklabelmode,
               obj.yticklabel, obj.ycolor, "y", plot_stream, ymirror, mono,
               "axis", obj.tickdir, ticklength, fontname, fontspec,
               obj.interpreter, obj.yscale, obj.ysgn, gnuplot_term);
    do_tics_1 ("manual", [], "off", obj.yticklabelmode, obj.yticklabel,
               obj.ycolor, "y2", plot_stream, ymirror, mono, "axis",
               "", "", fontname, fontspec, obj.interpreter, obj.yscale,
               obj.ysgn, gnuplot_term);
  else
    do_tics_1 (obj.ytickmode, obj.ytick, obj.yminortick, obj.yticklabelmode,
               obj.yticklabel, obj.ycolor, "y", plot_stream, ymirror, mono,
               "border", obj.tickdir, ticklength, fontname, fontspec,
               obj.interpreter, obj.yscale, obj.ysgn, gnuplot_term);
    do_tics_1 ("manual", [], "off", obj.yticklabelmode, obj.yticklabel,
               obj.ycolor, "y2", plot_stream, ymirror, mono, "border",
               "", "", fontname, fontspec, obj.interpreter, obj.yscale,
               obj.ysgn, gnuplot_term);
  endif
  do_tics_1 (obj.ztickmode, obj.ztick, obj.zminortick, obj.zticklabelmode,
             obj.zticklabel, obj.zcolor, "z", plot_stream, true, mono,
             "border", obj.tickdir, ticklength, fontname, fontspec,
             obj.interpreter, obj.zscale, obj.zsgn, gnuplot_term);
endfunction

function do_tics_1 (ticmode, tics, mtics, labelmode, labels, color, ax,
                    plot_stream, mirror, mono, axispos, tickdir, ticklength,
                    fontname, fontspec, interpreter, scale, sgn, gnuplot_term)
  persistent warned_latex = false;
  if (strcmpi (interpreter, "tex"))
    for n = 1 : numel(labels)
      labels{n} = __tex2enhanced__ (labels{n}, fontname, false, false);
    endfor
  elseif (strcmpi (interpreter, "latex"))
    if (! warned_latex)
      warning ("latex markup not supported for tick marks");
      warned_latex = true;
    endif
  endif
  if (strcmp (scale, "log"))
    num_mtics = 10;
    if (any (strcmp (gnuplot_term, {"tikz", "pstex", "pslatex", "epslatex"})))
      fmt = "$10^{%T}$";
    else
      fmt = "10^{%T}";
    endif
    if (sgn < 0)
      fmt = strcat ("-", fmt);
    endif
  else
    fmt = "%g";
    num_mtics = 5;
  endif
  colorspec = get_text_colorspec (color, mono);
  if (strcmpi (ticmode, "manual") || strcmpi (labelmode, "manual"))
    if (isempty (tics))
      fprintf (plot_stream, "unset %stics;\nunset m%stics;\n", ax, ax);
    elseif (strcmpi (labelmode, "manual"))
      if (ischar (labels))
        labels = cellstr (labels);
      endif
      if (isnumeric (labels))
        labels = num2str (real (labels(:)));
      endif
      if (ischar (labels))
        labels = permute (cellstr (labels), [2, 1]);
      endif
      if (iscellstr (labels))
        k = 1;
        ntics = numel (tics);
        nlabels = numel (labels);
        fprintf (plot_stream, "set format %s \"%%s\";\n", ax);
        if (mirror)
          fprintf (plot_stream, "set %stics %s %s %s mirror (", ax,
                   tickdir, ticklength, axispos);
        else
          fprintf (plot_stream, "set %stics %s %s %s nomirror (", ax,
                   tickdir, ticklength, axispos);
        endif

        labels = regexprep(labels, '%', "%%");
        for i = 1:ntics
          fprintf (plot_stream, " \"%s\" %.15g", labels{k++}, tics(i));
          if (i < ntics)
            fputs (plot_stream, ", ");
          endif
          if (k > nlabels)
            k = 1;
          endif
        endfor
        fprintf (plot_stream, ") %s %s;\n", colorspec, fontspec);
        if (strcmp (mtics, "on"))
          fprintf (plot_stream, "set m%stics %d;\n", ax, num_mtics);
        else
          fprintf (plot_stream, "unset m%stics;\n", ax);
        endif
     else
        error ("__go_draw_axes__: unsupported type of ticklabel");
      endif
    else
      fprintf (plot_stream, "set format %s \"%s\";\n", ax, fmt);
      if (mirror)
        fprintf (plot_stream, "set %stics %s %s %s mirror (", ax, tickdir,
                 ticklength, axispos);
      else
        fprintf (plot_stream, "set %stics %s %s %s nomirror (", ax, tickdir,
                 ticklength, axispos);
      endif
      fprintf (plot_stream, " %.15g,", tics(1:end-1));
      fprintf (plot_stream, " %.15g) %s;\n", tics(end), fontspec);
      if (strcmp (mtics, "on"))
        fprintf (plot_stream, "set m%stics %d;\n", ax, num_mtics);
      else
        fprintf (plot_stream, "unset m%stics;\n", ax);
      endif
    endif
  else
    fprintf (plot_stream, "set format %s \"%s\";\n", ax, fmt);
    if (mirror)
      fprintf (plot_stream, "set %stics %s %s %s mirror %s %s;\n", ax,
               axispos, tickdir, ticklength, colorspec, fontspec);
    else
      fprintf (plot_stream, "set %stics %s %s %s nomirror %s %s;\n", ax,
               tickdir, ticklength, axispos, colorspec, fontspec);
    endif
    if (strcmp (mtics, "on"))
      fprintf (plot_stream, "set m%stics %d;\n", ax, num_mtics);
    else
      fprintf (plot_stream, "unset m%stics;\n", ax);
    endif
  endif
endfunction

function ticklabel = ticklabel_to_cell (ticklabel)
  if (isnumeric (ticklabel))
    ## Use upto 5 significant digits
    ticklabel = num2str (ticklabel(:), 5);
  endif
  if (ischar (ticklabel))
    if (size (ticklabel, 1) == 1 && any (ticklabel == "|"))
      n = setdiff (findstr (ticklabel, "|"), findstr (ticklabel, '\|'));
      ticklabel = strsplit (ticklabel, "|");
    else
      ticklabel = cellstr (ticklabel);
    endif
  elseif (isempty (ticklabel))
    ticklabel = {""};
  else
    ticklabel = ticklabel;
  endif
endfunction

function colorspec = get_text_colorspec (color, mono)
  if (mono)
    colorspec = "";
  else
    colorspec = sprintf ("textcolor rgb \"#%02x%02x%02x\"",
                         round (255*color));
  endif
endfunction

function [f, s, fnt, it, bld] = get_fontname_and_size (t)
  if (isempty (t.fontname) || strcmp (t.fontname, "*"))
    fnt = "{}";
  else
    fnt = t.fontname;
  endif
  f = fnt;
  it = false;
  bld = false;
  if (! isempty (t.fontweight) && strcmpi (t.fontweight, "bold"))
    if (! isempty(t.fontangle)
        && (strcmpi (t.fontangle, "italic")
            || strcmpi (t.fontangle, "oblique")))
      f = cstrcat (f, "-bolditalic");
      it = true;
      bld = true;
    else
      f = cstrcat (f, "-bold");
      bld = true;
    endif
  elseif (! isempty(t.fontangle)
          && (strcmpi (t.fontangle, "italic")
              || strcmpi (t.fontangle, "oblique")))
    f = cstrcat (f, "-italic");
    it = true;
  endif
  if (isempty (t.fontsize))
    s = 10;
  else
    s = t.fontsize;
  endif
endfunction

function [str, f, s] = __maybe_munge_text__ (enhanced, obj, fld)

  persistent warned_latex = false;

  if (strcmp (fld, "string"))
    [f, s, fnt, it, bld] = get_fontname_and_size (obj);
  else
    f = "Helvetica";
    s = 10;
    fnt = f;
    it = false;
    bld = false;
  endif

  ## The text object maybe multiline, and may be of any class
  str = getfield (obj, fld);
  if (ischar (str) && size (str, 1) > 1)
    str = cellstr (str);
  elseif (isnumeric (str))
    str = cellstr (num2str (str(:)));
  endif
  if (iscellstr (str))
    for n = 1:numel(str)
      if (isnumeric (str{n}))
        str{n} = num2str (str{n});
      endif
    endfor
    str = sprintf ("%s\n", str{:})(1:end-1);
  endif

  if (enhanced)
    if (strcmpi (obj.interpreter, "tex"))
      if (iscellstr (str))
        for n = 1:numel(str)
          str{n} = __tex2enhanced__ (str{n}, fnt, it, bld);
        endfor
      else
        str = __tex2enhanced__ (str, fnt, it, bld);
      endif
    elseif (strcmpi (obj.interpreter, "latex"))
      if (! warned_latex)
        warning ("latex markup not supported for text objects");
        warned_latex = true;
      endif
    elseif (enhanced)
      str = no_super_sub_scripts (str);
    endif
  endif
endfunction

function str = no_super_sub_scripts (str)
  if (iscellstr (str))
    labels = str;
  else
    labels = cellstr (str);
  endif
  for marker = "_^" 
    for m = 1 : numel(labels)
      n1 = strfind (labels{m}, sprintf ("\\%s", marker));
      n2 = strfind (labels{m}, marker);
      if (! isempty (n1))
        n1 = n1 + 1;
        n2 = setdiff (n2, n1);
      end
      for n = numel(n2):-1:1
        labels{m} = [labels{m}(1:n2(n)-1), "\\", labels{m}(n2(n):end)]
      endfor
    endfor
  endfor
  if (iscellstr (str))
    str = labels;
  else
    str = char (labels);
  endif
endfunction

function str = __tex2enhanced__ (str, fnt, it, bld)
  persistent sym = __setup_sym_table__ ();
  persistent flds = fieldnames (sym);

  [s, e, m] = regexp(str,'\\([a-zA-Z]+|0)','start','end','matches');

  for i = length (s) : -1 : 1
    ## special case for "\0"  and replace with "{/Symbol \306}'
    if (strncmp (m{i}, '\0', 2))
      str = cstrcat (str(1:s(i) - 1), '{/Symbol \306}', str(s(i) + 2:end));
    else
      f = m{i}(2:end);
      if (isfield (sym, f))
        g = getfield(sym, f);
        ## FIXME The symbol font doesn't seem to support bold or italic
        ##if (bld)
        ##  if (it)
        ##    g = regexprep (g, '/Symbol', '/Symbol-bolditalic');
        ##  else
        ##    g = regexprep (g, '/Symbol', '/Symbol-bold');
        ##  endif
        ##elseif (it)
        ##  g = regexprep (g, '/Symbol', '/Symbol-italic');
        ##endif
        str = cstrcat (str(1:s(i) - 1), g, str(e(i) + 1:end));
      elseif (strncmp (f, "rm", 2))
        bld = false;
        it = false;
        str = cstrcat (str(1:s(i) - 1), '/', fnt, ' ', str(s(i) + 3:end));
      elseif (strncmp (f, "it", 2) || strncmp (f, "sl", 2))
        it = true;
        if (bld)
          str = cstrcat (str(1:s(i) - 1), '/', fnt, '-bolditalic ',
                        str(s(i) + 3:end));
        else
          str = cstrcat (str(1:s(i) - 1), '/', fnt, '-italic ',
                        str(s(i) + 3:end));
        endif
      elseif (strncmp (f, "bf", 2))
        bld = true;
        if (it)
          str = cstrcat (str(1:s(i) - 1), '/', fnt, '-bolditalic ',
                        str(2(i) + 3:end));
        else
          str = cstrcat (str(1:s(i) - 1), '/', fnt, '-bold ',
                        str(s(i) + 3:end));
        endif
      elseif (strcmpi (f, "color"))
        ## FIXME Ignore \color but remove trailing {} block as well
        d = strfind(str(e(i) + 1:end),'}');
        if (isempty (d))
          warning ('syntax error in \color argument');
        else
          str = cstrcat (str(1:s(i) - 1), str(e(i) + d + 1:end));
        endif
      elseif(strcmpi (f, "fontname"))
        b1 = strfind(str(e(i) + 1:end),'{');
        b2 = strfind(str(e(i) + 1:end),'}');
        if (isempty(b1) || isempty(b2))
          warning ('syntax error in \fontname argument');
        else
          str = cstrcat (str(1:s(i) - 1), '/',
                        str(e(i)+b1(1) + 1:e(i)+b2(1)-1), '{}',
                        str(e(i) + b2(1) + 1:end));
        endif
      elseif(strcmpi (f, "fontsize"))
        b1 = strfind(str(e(i) + 1:end),'{');
        b2 = strfind(str(e(i) + 1:end),'}');
        if (isempty(b1) || isempty(b2))
          warning ('syntax error in \fontname argument');
        else
          str = cstrcat (str(1:s(i) - 1), '/=',
                        str(e(i)+b1(1) + 1:e(i)+b2(1)-1), '{}',
                        str(e(i) + b2(1) + 1:end));
        endif
      else
        ## Last desperate attempt to treat the symbol. Look for things
        ## like \pix, that should be translated to the symbol Pi and x
        for j = 1 : length (flds)
          if (strncmp (flds{j}, f, length (flds{j})))
            g = getfield(sym, flds{j});
            ## FIXME The symbol font doesn't seem to support bold or italic
            ##if (bld)
            ##  if (it)
            ##    g = regexprep (g, '/Symbol', '/Symbol-bolditalic');
            ##  else
            ##    g = regexprep (g, '/Symbol', '/Symbol-bold');
            ##  endif
            ##elseif (it)
            ##  g = regexprep (g, '/Symbol', '/Symbol-italic');
            ##endif
            str = cstrcat (str(1:s(i) - 1), g,
                          str(s(i) + length (flds{j}) + 1:end));
            break;
          endif
        endfor
      endif
    endif
  endfor

  ## Prepend @ to things  things like _0^x or _{-100}^{100} for
  ## alignment But need to put the shorter of the two arguments first.
  ## Carful of nested {} and unprinted characters when defining
  ## shortest.. Don't have to worry about things like ^\theta as they
  ## are already converted to ^{/Symbol q}.

  ## FIXME -- This is a mess... Is it worth it just for a "@" character?

  [s, m] = regexp(str,'[_\^]','start','matches');
  i = 1;
  p = 0;
  while (i < length (s))
    if (i < length(s))
      if (str(s(i) + p + 1) == "{")
        s1 = strfind(str(s(i) + p + 2:end),'{');
        si = 1;
        l1 = strfind(str(s(i) + p + 1:end),'}');
        li = 1;
        while (li <= length (l1) && si <= length (s1))
          if (l1(li) < s1(si))
            if (li == si)
              break;
            endif
            li++;
          else
            si++;
          endif
        endwhile
        l1 = l1 (min (length(l1), si));
        if (s(i) + l1 + 1 == s(i+1))
          if (str(s(i + 1) + p + 1) == "{")
            s2 = strfind(str(s(i + 1) + p + 2:end),'{');
            si = 1;
            l2 = strfind(str(s(i + 1) + p + 1:end),'}');
            li = 1;
            while (li <= length (l2) && si <= length (s2))
              if (l2(li) < s2(si))
                if (li == si)
                  break;
                endif
                li++;
              else
                si++;
              endif
            endwhile
            l2 = l2 (min (length(l2), si));
            if (length_string (str(s(i)+p+2:s(i)+p+l1-1)) <=
                length_string(str(s(i+1)+p+2:s(i+1)+p+l2-1)))
              ## Shortest already first!
              str = cstrcat (str(1:s(i)+p-1), "@", str(s(i)+p:end));
            else
              ## Have to swap sub/super-script to get shortest first.
              str = cstrcat (str(1:s(i)+p-1), "@", str(s(i+1)+p:s(i+1)+p+l2),
                            str(s(i)+p:s(i)+p+l1), str(s(i+1)+p+l2+1:end));
            endif
          else
            ## Have to swap sub/super-script to get shortest first.
            str = cstrcat (str(1:s(i)+p-1), "@", str(s(i+1)+p:s(i+1)+p+1),
                          str(s(i)+p:s(i)+p+l1), str(s(i+1)+p+2:end));
          endif
          i += 2;
          p ++;
        else
          i++;
        endif
      else
        if (s(i+1) == s(i) + 2)
          ## Shortest already first!
          str = cstrcat (str(1:s(i)+p-1), "@", str(s(i)+p:end));
          p ++;
          i += 2;
        else
          i ++;
        endif
      endif
    else
      i ++;
    endif
  endwhile

endfunction

function l = length_string (s)
  l = length (s) - length (strfind(s,'{')) - length (strfind(s,'}'));
  m = regexp (s, '/([\w-]+|[\w-]+=\d+)', 'matches');
  if (!isempty (m))
    l = l - sum (cellfun ("length", m));
  endif
endfunction

function sym = __setup_sym_table__ ()
  ## Setup the translation table for TeX to gnuplot enhanced mode.
  sym.forall = '{/Symbol \042}';
  sym.exists = '{/Symbol \044}';
  sym.ni = '{/Symbol \047}';
  sym.cong = '{/Symbol \100}';
  sym.Delta = '{/Symbol D}';
  sym.Phi = '{/Symbol F}';
  sym.Gamma = '{/Symbol G}';
  sym.vartheta = '{/Symbol J}';
  sym.Lambda = '{/Symbol L}';
  sym.Pi = '{/Symbol P}';
  sym.Theta = '{/Symbol Q}';
  sym.Sigma = '{/Symbol S}';
  sym.varsigma = '{/Symbol V}';
  sym.Omega = '{/Symbol W}';
  sym.Xi = '{/Symbol X}';
  sym.Psi = '{/Symbol Y}';
  sym.perp = '{/Symbol \136}';
  sym.alpha = '{/Symbol a}';
  sym.beta = '{/Symbol b}';
  sym.chi = '{/Symbol c}';
  sym.delta = '{/Symbol d}';
  sym.epsilon = '{/Symbol e}';
  sym.phi = '{/Symbol f}';
  sym.gamma = '{/Symbol g}';
  sym.eta = '{/Symbol h}';
  sym.iota = '{/Symbol i}';
  sym.varphi = '{/Symbol j}';
  sym.kappa = '{/Symbol k}';
  sym.lambda = '{/Symbol l}';
  sym.mu = '{/Symbol m}';
  sym.nu = '{/Symbol n}';
  sym.o =  '{/Symbol o}';
  sym.pi = '{/Symbol p}';
  sym.theta = '{/Symbol q}';
  sym.rho = '{/Symbol r}';
  sym.sigma = '{/Symbol s}';
  sym.tau = '{/Symbol t}';
  sym.upsilon = '{/Symbol u}';
  sym.varpi = '{/Symbol v}';
  sym.omega = '{/Symbol w}';
  sym.xi = '{/Symbol x}';
  sym.psi = '{/Symbol y}';
  sym.zeta = '{/Symbol z}';
  sym.sim = '{/Symbol \176}';
  sym.Upsilon = '{/Symbol \241}';
  sym.prime = '{/Symbol \242}';
  sym.leq = '{/Symbol \243}';
  sym.infty = '{/Symbol \245}';
  sym.clubsuit = '{/Symbol \247}';
  sym.diamondsuit = '{/Symbol \250}';
  sym.heartsuit = '{/Symbol \251}';
  sym.spadesuit = '{/Symbol \252}';
  sym.leftrightarrow = '{/Symbol \253}';
  sym.leftarrow = '{/Symbol \254}';
  sym.uparrow = '{/Symbol \255}';
  sym.rightarrow = '{/Symbol \256}';
  sym.downarrow = '{/Symbol \257}';
  sym.circ = '{/Symbol \260}';
  sym.pm = '{/Symbol \261}';
  sym.geq = '{/Symbol \263}';
  sym.times = '{/Symbol \264}';
  sym.propto = '{/Symbol \265}';
  sym.partial = '{/Symbol \266}';
  sym.bullet = '{/Symbol \267}';
  sym.div = '{/Symbol \270}';
  sym.neq = '{/Symbol \271}';
  sym.equiv = '{/Symbol \272}';
  sym.approx = '{/Symbol \273}';
  sym.ldots = '{/Symbol \274}';
  sym.mid = '{/Symbol \275}';
  sym.aleph = '{/Symbol \300}';
  sym.Im = '{/Symbol \301}';
  sym.Re = '{/Symbol \302}';
  sym.wp = '{/Symbol \303}';
  sym.otimes = '{/Symbol \304}';
  sym.oplus = '{/Symbol \305}';
  sym.oslash = '{/Symbol \306}';
  sym.cap = '{/Symbol \307}';
  sym.cup = '{/Symbol \310}';
  sym.supset = '{/Symbol \311}';
  sym.supseteq = '{/Symbol \312}';
  sym.subset = '{/Symbol \314}';
  sym.subseteq = '{/Symbol \315}';
  sym.in = '{/Symbol \316}';
  sym.notin = '{/Symbol \317}';
  sym.angle = '{/Symbol \320}';
  sym.bigtriangledown = '{/Symbol \321}';
  sym.langle = '{/Symbol \341}';
  sym.rangle = '{/Symbol \361}';
  sym.nabla = '{/Symbol \321}';
  sym.prod = '{/Symbol \325}';
  sym.surd = '{/Symbol \326}';
  sym.cdot = '{/Symbol \327}';
  sym.neg = '{/Symbol \330}';
  sym.wedge = '{/Symbol \331}';
  sym.vee = '{/Symbol \332}';
  sym.Leftrightarrow = '{/Symbol \333}';
  sym.Leftarrow = '{/Symbol \334}';
  sym.Uparrow = '{/Symbol \335}';
  sym.Rightarrow = '{/Symbol \336}';
  sym.Downarrow = '{/Symbol \337}';
  sym.diamond = '{/Symbol \340}';
  sym.copyright = '{/Symbol \343}';
  sym.lfloor = '{/Symbol \353}';
  sym.lceil  = '{/Symbol \351}';
  sym.rfloor = '{/Symbol \373}';
  sym.rceil  = '{/Symbol \371}';
  sym.int = '{/Symbol \362}';
endfunction

function retval = __do_enhanced_option__ (enhanced, obj)
  retval = "";
  if (enhanced)
    if (strcmpi (obj.interpreter, "none"))
      retval = "noenhanced";
    else
      retval = "enhanced";
    endif
  endif
endfunction
