--- a/scripts/ChangeLog	Tue Feb 13 08:10:51 2007 +0000
+++ b/scripts/ChangeLog	Tue Feb 13 09:11:53 2007 +0000
@@ -1,5 +1,8 @@
 2007-02-13  John W. Eaton  <jwe@octave.org>
 
+	* plot/stem.m: New file, adapted from OctPlot.
+	* plot/Makefile.in (SOURCES_M): Add it to the list.
+
 	* plot/__errcomm__.m, plot/__plr1__.m, plot/__plr2__.m,
 	plot/__plt1__.m, plot/__plt2__.m, plot/__plt2mm__.m,
 	plot/__plt2mv__.m, plot/__plt2ss__.m, plot/__plt2vm__.m,

--- a/scripts/plot/Makefile.in	Tue Feb 13 08:10:51 2007 +0000
+++ b/scripts/plot/Makefile.in	Tue Feb 13 09:11:53 2007 +0000
@@ -99,6 +99,7 @@
   shg.m \
   sombrero.m \
   stairs.m \
+  stem.m \
   subplot.m \
   text.m \
   title.m \

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/scripts/plot/stem.m	Tue Feb 13 09:11:53 2007 +0000
@@ -0,0 +1,296 @@
+## Copyright (C) 2006 Michel D. Schmid
+##
+## This program 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 2, or (at your option)
+## any later version.
+##
+## OctPlot 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 OctPlot; see the file COPYING.  If not, write to the Free
+## Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+## 02111-1307, USA.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {@var{h} =} stem (@var{x}, @var{y}, @var{linespec})
+## Plot a stem graph and return the handles of hte line and marker
+## objects used to draw the stems.  The default color is @code{"r"}
+## (red). The default line style is @code{"-"} and the default marker is
+## @code{"o"}.
+##
+## For example,
+## @example
+## x = 1:10;
+## stem (x);
+## @end example
+## @noindent
+## plots 10 stems with hights from 1 to 10;
+##
+## @example
+## x = 1:10;
+## y = ones (1, length (x))*2.*x;
+## stem (x, y);
+## @end example
+## @noindent
+## plots 10 stems with hights from 2 to 20;
+## 
+## @example
+## x = 1:10;
+## y = ones (size (x))*2.*x;
+## h = stem (x, y, "b");
+## @end example
+## @noindent
+## plots 10 bars with hights from 2 to 20
+## (the color is blue, and @var{h} is a 2-by-10 array of handles in
+## which the first row holds the line handles and the 
+## the second row holds the marker handles);
+##
+## @example
+## x = 1:10;
+## y = ones (size (x))*2.*x;
+## h = stem (x, y, "-.k");
+## @end example
+## @noindent
+## plots 10 stems with hights from 2 to 20
+## (the color is black, line style is @code{"-."}, and @var{h} is a 2-by-10
+## array of handles in which the first row holds the line handles and
+## the second rows holds the marker handles);
+##
+## @example
+## x = 1:10;
+## y = ones (size (x))*2.*x;
+## h = stem (x, y, "-.k.");
+## @end example
+## @noindent
+## plots 10 stems with hights from 2 to 20
+## (the color is black, line style is @code{"-."} and the marker style
+## is @code{"."}, and @var{h} is a 2-by-10 array of handles in which the
+## first row holds the line handles and the second row holds the marker
+## handles);
+##
+## @example
+## x = 1:10;
+## y = ones (size (x))*2.*x;
+## h = stem (x, y, "fill");
+## @end example
+## @noindent
+## plots 10 stems with hights from 2 to 20
+## (the color is rgb-triple defined, the line style is @code{"-"},
+## the marker style is @code{"o"}, and @var{h} is a 2-by-10 array of
+## handles in which the first row holds the line handles and the second
+## row holds the marker handles).
+##
+## Color definitions with rgb-triples are not valid!
+##
+## @seealso{bar, barh, plot}
+## @end deftypefn
+
+## Author: Michel D. Schmid <michaelschmid@users.sourceforge.net>
+## Adapted-by: jwe
+
+function h = stem (varargin)
+
+  if (nargin < 1 || nargin > 4)
+    print_usage ();
+  endif
+
+  [x, y, dofill, lc, ls, mc, ms] = check_stem_arg (varargin{:});
+
+  newplot ();
+
+  ## first, plot the lines.. without marker
+  ## Use a loop and calls to line here because setting properties this
+  ## way doesn't work with plot yet.
+  idxhh = 0;
+  for i = 1:numel(x)
+    hh(++idxhh) = line ([x(i); x(i)], [0; y(i)], "color", lc, "linestyle", ls);
+  endfor
+
+  ## second, plot the markers..
+  hhh = [];
+  hhhh = [];
+
+  ## Use a loop and calls to line here because setting properties this
+  ## way doesn't work with plot yet.
+  idxhhh = 0;
+  for i = 1:numel(x)
+    hhh(++idxhhh) = line ([x(i); x(i)], [y(i); y(i)]);
+  endfor
+
+  if (find (y < 0))
+    x_axis_range = get (gca, "xlim");
+    hhhh = line (x_axis_range, [0, 0], "color", "k");
+  endif
+
+  if (dofill)
+    set (hhh, "markerfacecolor", mc);
+  endif
+
+  if (nargout > 0)
+    if (! isempty (hhhh))
+      hhhh = hhhh*(ones (length (hh), 1))';
+    endif
+    h = [hh; hhh; hhhh];
+  endif
+
+endfunction
+
+function [x, y, dofill, lc, ls, mc, ms] = check_stem_arg (varargin)
+
+  ## set specifiers to default values
+  [lc, ls, mc, ms] = set_default_values ();
+  dofill = 0;
+  fill_2 = 0;
+  linespec_2 = 0;
+
+  ## check input arguments
+  if (nargin == 1)
+    y = varargin{1};
+    if (isvector (y))
+      x = 1:length(y);
+    elseif (ismatrix (y))
+      x = 1:rows(y);
+    else 
+      error ("stem: Y must be a matrix");
+    endif # in each case, x & y will be defined
+
+  elseif (nargin == 2)
+    ## several possibilities
+    ## 1. the real y data
+    ## 2. 'fill'
+    ## 3. line spec
+    if (ischar (varargin{2}))
+      ## only 2. or 3. possible
+      if (strcmp ("fill", varargin{2}))
+	dofill = 1;
+      else
+	## parse the linespec
+	[lc, ls, mc, ms] = stem_line_spec (varargin{2});
+      endif
+      y = varargin{1};
+      if (isvector (y))
+	x = 1:length(y);
+      elseif (ismatrix (y))
+	x = 1:rows(y);
+      else
+	error ("stem: Y must be a matrix");
+      endif # in each case, x & y will be defined
+    else
+      ## must be the real y data
+      x = varargin{1};
+      y = varargin{2};
+      if (! (ismatrix (x) && ismatrix (y)))
+	error ("stem: X and Y must be matrices");
+      endif
+    endif
+  elseif (nargin == 3)
+    ## again several possibilities
+    ## arg2 1. real y
+    ## arg2 2. 'fill' or linespec
+    ## arg3 1. 'fill' or linespec
+    if (ischar (varargin{2}))
+      ## only arg2 2. / arg3 1. & arg3 3. are possible
+      if (strcmp ("fill", varargin{2}))
+	dofill = 1;
+	fill_2 = 1; # be sure, no second "fill" is in the arguments
+      else
+	## must be a linespec
+	[lc, ls, mc, ms] = stem_line_spec (varargin{2});
+	linespec_2 = 1;
+      endif
+      y = varargin{1};
+      if (isvector (y))
+	x = 1:length(y);
+      elseif (ismatrix (y))
+	x = 1:size(y,1);
+      else
+	error ("stem: Y must be a matrix");
+      endif # in each case, x & y will be defined
+    else
+      ## must be the real y data
+      x = varargin{1};
+      y = varargin{2};
+      if (! (ismatrix (x) && ismatrix (y)))
+	error ("stem: X and Y must be matrices");
+      endif
+    endif # if ischar(varargin{2})
+    ## varargin{3} must be char...
+    ## check for "fill" ..
+    if (strcmp ("fill", varargin{3}) & fill_2)
+      error ("stem:check_stem_arg: duplicate fill argument");
+    elseif (strcmp("fill", varargin{3}) & linespec_2)
+      # must be "fill"
+      dofill = 1;
+      fill_2 = 1;
+    elseif (strcmp ("fill", varargin{3}) & ! linespec_2)
+      ## must be "fill"
+      dofill = 1;
+      fill_2 = 1;
+    elseif (! linespec_2)
+      ## must be linespec
+      [lc, ls, mc, ms] = stem_line_spec (varargin{3});
+      linespec_2 = 1;
+    endif
+  elseif (nargin == 4)
+    x = varargin{1};
+    y = varargin{2};
+    if (! (ismatrix (x) && ismatrix (y)))
+      error ("X and Y must be matrices");
+    endif
+
+    if (strcmp ("fill", varargin{3}))
+      dofill = 1;
+      fill_2 = 1; # be sure, no second "fill" is in the arguments
+    else
+      ## must be a linespec
+      [lc, ls, mc, ms] = stem_line_spec (varargin{3});
+      linespec_2 = 1;
+    endif
+
+    ## check for "fill" ..
+    if (strcmp ("fill", varargin{4}) & fill_2)
+      error ("stem:check_stem_arg: duplicate fill argument");
+    elseif (strcmp ("fill", varargin{4}) & linespec_2)
+      ## must be "fill"
+      dofill = 1;
+      fill_2 = 1;
+    elseif (! strcmp ("fill", varargin{4}) & ! linespec_2)
+      ## must be linespec
+      [lc, ls, mc, ms] = stem_line_spec (varargin{4});
+      linespec_2 = 1;
+    endif
+  endif
+
+endfunction
+
+function [lc, ls, mc, ms] = stem_line_spec (str)
+  if (! ischar (str))
+    error ("stem:stem_line_spec: wrong argument type, must be \"fill\" or a string of specifiers");
+  endif
+  [lc, ls, mc, ms] = set_default_values ();
+  ## Parse the line specifier string.
+  cur_props = __pltopt__ ("stem", str);
+  for i = 1:length(cur_props)
+    if (isfield (cur_props(i), "markeredgecolor"))
+      mc = cur_props(i).markeredgecolor;
+    elseif (isfield (cur_props(i), "color")); # means line color
+      lc = cur_props(i).color;
+    elseif (isfield (cur_props(i), "linestyle"))
+      ls = cur_props(i).linestyle;
+    elseif (isfield (cur_props(i), "marker"))
+      ms = cur_props(i).marker;
+    endif
+  endfor
+endfunction
+
+function [lc, ls, mc, ms] = set_default_values ()
+  ## set default values
+  mc = "r";
+  lc = "r";
+  ls = "-";
+  ms = "o";
+endfunction