--- /dev/null
+## Copyright (C) 2008-2012 David Bateman
+##
+## 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} {} refreshdata ()
+## @deftypefnx {Function File} {} refreshdata (@var{h})
+## @deftypefnx {Function File} {} refreshdata (@var{h}, @var{workspace})
+## Evaluate any @samp{datasource} properties of the current figure and update
+## the plot if the corresponding data has changed. If called with one or more
+## arguments @var{h} is a scalar or array of figure handles to refresh. The
+## optional second argument @var{workspace} can take the following values.
+##
+## @table @asis
+## @item "base"
+## Evaluate the datasource properties in the base workspace. (default).
+##
+## @item "caller"
+## Evaluate the datasource properties in the workspace of the function
+## that called @code{refreshdata}.
+## @end table
+##
+## An example of the use of @code{refreshdata} is:
+##
+## @example
+## @group
+## x = 0:0.1:10;
+## y = sin (x);
+## plot (x, y, "ydatasource", "y");
+## for i = 1 : 100
+## pause (0.1);
+## y = sin (x + 0.1*i);
+## refreshdata ();
+## endfor
+## @end group
+## @end example
+## @end deftypefn
+
+function refreshdata (h, workspace)
+
+ if (nargin == 0)
+ h = gcf ();
+ workspace = "base";
+ else
+ if (iscell (h))
+ h = [h{:}];
+ endif
+ if (!all (ishandle (h)) || !all (strcmp (get (h, "type"), "figure")))
+ error ("refreshdata: expecting a list of figure handles");
+ endif
+ if (nargin < 2)
+ workspace = "base";
+ else
+ if ( !ischar (workspace)
+ || !(strcmpi (workspace, "base")
+ || strcmpi (workspace, "caller")))
+ error ("refreshdata: expecting WORKSPACE to be \"base\" or ""caller\"");
+ else
+ workspace = tolower (workspace);
+ endif
+ endif
+ endif
+
+ h = findall (h);
+ objs = [];
+ props = {};
+
+ for i = 1 : numel (h)
+ obj = get (h (i));
+ fldnames = fieldnames (obj);
+ m = regexpi (fieldnames(obj), '^.+datasource$', "match");
+ idx = ! cellfun ("isempty", m);
+ if (any (idx))
+ tmp = m(idx);
+ props = [props; {vertcat(tmp{:})}];
+ objs = [objs ; h(i)];
+ endif
+ endfor
+
+ for i = 1 : length (objs)
+ for j = 1 : length (props {i})
+ expr = get (objs(i), props{i}{j});
+ if (!isempty (expr))
+ val = evalin (workspace, expr);
+ prop = props{i}{j}(1:end-6);
+ if (! isequal (get (objs(i), prop), val))
+ set (objs(i), props{i}{j}(1:end-6), val);
+ endif
+ endif
+ endfor
+ endfor
+endfunction
+
+%!demo
+%! clf
+%! x = 0:0.1:10;
+%! y = sin (x);
+%! plot (x, y, "ydatasource", "y");
+%! for i = 1 : 100
+%! pause(0.1)
+%! y = sin (x + 0.1 * i);
+%! refreshdata(gcf(), "caller");
+%! endfor