## Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
##               Teemu Ikonen
##
## 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} {@var{h} =} __errplot__ (@var{fstr}, @var{p}, @dots{})
## Undocumented internal function.
## @end deftypefn

## Created: 18.7.2000
## Author: Teemu Ikonen <tpikonen@pcu.helsinki.fi>
## Keywords: errorbar, plotting

function h = __errplot__ (fstr, p, a1, a2, a3, a4, a5, a6)

  if (nargin < 4 || nargin > 8) # at least two data arguments needed
    print_usage ();
  endif

  [fmt, key] = __pltopt__ ("__errplot__", fstr);

  [len, nplots] = size (a1);
  h = [];

  for i = 1:nplots
    ## Set the plot type based on linestyle.

    if (strcmp (fmt.errorstyle, "~"))
      ifmt = "yerr";
    elseif (strcmp (fmt.errorstyle, ">"))
      ifmt = "xerr";
    elseif (strcmp (fmt.errorstyle, "~>"))
      ifmt = "xyerr";
    elseif (strcmp (fmt.errorstyle, "#"))
      ifmt = "box";
    elseif (strcmp (fmt.errorstyle, "#~"))
      ifmt = "boxy";
    elseif (strcmp (fmt.errorstyle, "#~>"))
      ifmt = "boxxy";
    else
      ifmt = "~";
    endif

    hg = hggroup ("parent", p);
    h = [h; hg];
    args = __add_datasource__ ("__errplot__", hg, 
                               {"x", "y", "l", "u", "xl", "xu"});

    if (isempty (fmt.marker) && isempty (fmt.linestyle))
      [linestyle, marker] = __next_line_style__ ();
      if (isempty (fmt.color))
        hl = __line__ (hg, "linestyle", linestyle, "marker", "none",
                       "color", __next_line_color__ ());
      else
        hl = __line__ (hg, "linestyle", linestyle, "marker", "none",
                       "color", fmt.color);
      endif
    else
      if (isempty (fmt.color))
        hl = __line__ (hg, "linestyle", fmt.linestyle, "marker", "none",
                       "color", __next_line_color__ ());
      else
        hl = __line__ (hg, "linestyle", fmt.linestyle, "marker", "none",
                       "color", fmt.color);
      endif
      marker = fmt.marker;
    endif

    ## FIXME -- note the code below adds the errorbar data directly as
    ## ldata, etc properties of the line objects, as gnuplot can handle
    ## this.  Matlab has the errorbar part of the plot as a special line
    ## object with embedded NaNs that draws the three segments of the
    ## bar separately.  Should we duplicate Matlab's behavior and stop
    ## using the ldata, etc. properties of the line objects that are
    ## Octace specific?

    switch (nargin - 2)
      case 1
        error ("error plot requires 2, 3, 4 or 6 columns");
      case 2
        if (index (ifmt, "xerr"))
          set (hl, "xdata", (1:len)', "ydata", a1(:,i), "xldata", a2(:,i),
               "xudata", a2(:,i));
        elseif (index (ifmt, "yerr"))
          set (hl, "xdata", (1:len)', "ydata", a1(:,i), "ldata", a2(:,i),
               "udata", a2(:,i));
        else
          error ("2 column errorplot is only valid or xerr or yerr");
        endif
      case 3
        if (index (ifmt, "boxxy") || index (ifmt, "xyerr"))
          set (hl, "xdata", (1:len)', "ydata", a1(:,i), "xldata", a2(:,i), 
               "xudata", a2(:,i), "ldata", a3(:,i), "udata", a3(:,i));
        elseif (index (ifmt, "xerr"))
          set (hl, "xdata", a1(:,i), "ydata", a2(:,i), "xldata", a3(:,i),
               "xudata", a3(:,i));
        else
          set (hl, "xdata", a1(:,i), "ydata", a2(:,i), "ldata", a3(:,i),
               "udata", a3(:,i));
        endif
      case 4
        if (index (ifmt, "boxxy") || index (ifmt, "xyerr"))
          set (hl, "xdata", a1(:,i), "ydata", a2(:,i), "xldata", a3(:,i), 
               "xudata", a3(:,i), "ldata", a4(:,i), "udata", a4(:,i));
        elseif (index (ifmt, "xerr"))
          set (hl, "xdata", a1(:,i), "ydata", a2(:,i), "xldata", a3(:,i),
               "xudata", a4(:,i));
        else
          set (hl, "xdata", a1(:,i), "ydata", a2(:,i), "ldata", a3(:,i),
               "udata", a4(:,i));
        endif
      case 5
        error ("error plot requires 2, 3, 4 or 6 columns");
      case 6
        if (index (ifmt, "boxxy") || index (ifmt, "xyerr"))
          set (hl, "xdata", a1(:,i), "ydata", a2(:,i), "xldata", a3(:,i),
               "xudata", a4(:,i), "ldata", a5(:,i), "udata", a6(:,i));
        else
          error ("error plot with 6 columns only valid for boxxy and xyerr");
        endif
    endswitch

    hl2 = __line__ (hg, "xdata", get (hl, "xdata"), 
                    "ydata", get (hl, "ydata"), 
                    "color", get (hl, "color"),
                    "linewidth", get (hl, "linewidth"),
                    "linestyle", get (hl, "linestyle"), 
                    "marker", marker, "parent", hg);

    addproperty ("color", hg, "linecolor", get (hl, "color"));
    addproperty ("linewidth", hg, "linelinewidth", get (hl, "linewidth"));
    addproperty ("linestyle", hg, "linelinestyle", get (hl, "linestyle"));
    addproperty ("marker", hg, "linemarker", get (hl2, "marker"));
    addproperty ("markerfacecolor", hg, "linemarkerfacecolor", 
                 get (hl2, "markerfacecolor"));
    addproperty ("markeredgecolor", hg, "linemarkerfacecolor", 
                 get (hl2, "markeredgecolor"));
    addproperty ("markersize", hg, "linemarkersize", 
                 get (hl2, "markersize"));

    addlistener (hg, "color", @update_props);
    addlistener (hg, "linewidth", @update_props); 
    addlistener (hg, "linestyle", @update_props); 
    addlistener (hg, "marker", @update_marker); 
    addlistener (hg, "markerfacecolor", @update_marker); 
    addlistener (hg, "markersize", @update_marker);

    addproperty ("xdata", hg, "data", get (hl, "xdata"));
    addproperty ("ydata", hg, "data", get (hl, "ydata"));
    addproperty ("ldata", hg, "data", get (hl, "ldata"));
    addproperty ("udata", hg, "data", get (hl, "udata"));
    addproperty ("xldata", hg, "data", get (hl, "xldata"));
    addproperty ("xudata", hg, "data", get (hl, "xudata"));

    addlistener (hg, "xdata", @update_data);
    addlistener (hg, "ydata", @update_data);
    addlistener (hg, "ldata", @update_data);
    addlistener (hg, "udata", @update_data);
    addlistener (hg, "xldata", @update_data);
    addlistener (hg, "xudata", @update_data);

  endfor

endfunction

function update_props (h, d)
  set (get (h, "children"), "color", get (h, "color"), 
       "linewidth", get (h, "linewidth"), "linestyle", get (h, "linestyle"));
endfunction

function update_marker (h, d)
  kids = get (h, "children");
  kids (! cellfun (@isempty, get (kids, "ldata"))
        & ! cellfun (@isempty, get (kids, "xldata"))) = [];
  set (kids, "marker", get (h, "marker"), "markersize", get (h, "markersize"),
       "markerfacecolor", get (h, "markerfacecolor"), "markeredgecolor", 
       get (h, "markeredgecolor"));
endfunction

function update_data (h, d)
  x = get (h, "xdata");
  y = get (h, "ydata");
  l = get (h, "ldata");
  u = get (h, "udata");
  xl = get (h, "xldata");
  xu = get (h, "xudata");

  kids = get (h, "children");
  set (kids(1), "xdata", x, "ydata", y);
  set (kids(2), "xdata", x, "ydata", y, "ldata", l, "udata", u, 
       "xldata", xl, "xudata", xu);
endfunction