time   calls  line
                  1 function h = gcf()
                  2 %GCF Get handle to current figure.
                  3 %   H = GCF returns the handle of the current figure. The current
                  4 %   figure is the window into which graphics commands like PLOT,
                  5 %   TITLE, SURF, etc. will draw.
                  6 %
                  7 %   The handle of the current figure is stored in the root
                  8 %   property CurrentFigure, and can be queried directly using GET,
                  9 %   and modified using FIGURE or SET.
                 10 %
                 11 %   Clicking on uimenus and uicontrols contained within a figure,
                 12 %   or clicking on the drawing area of a figure cause that
                 13 %   figure to become current.
                 14 %
                 15 %   The current figure is not necessarily the frontmost figure on
                 16 %   the screen.
                 17 %
                 18 %   GCF should not be relied upon during callbacks to obtain the
                 19 %   handle of the figure whose callback is executing - use GCBO
                 20 %   for that purpose.
                 21 %
                 22 %   See also FIGURE, CLOSE, CLF, GCA, GCBO, GCO, GCBF.
                 23 
                 24 %   Copyright 1984-2002 The MathWorks, Inc. 
                 25 %   $Revision: 5.17 $  $Date: 2002/04/10 17:07:02 $
                 26 
  0.09    2137   27 h = get(0,'CurrentFigure'); 
                 28 
                 29 % 'CurrentFigure' is no longer guaranteed to return a figure,
                 30 % so we might need to create one (because gcf IS guaranteed to
                 31 % return a figure)
          2137   32 if isempty(h) 
                 33   h = figure;
                 34 end