function dummy = plotcircle(Editor)
%PLOTCIRCLE  Plots unit circle in Root Locus editor.
%
%    See also SISOTOOL.

%	 Authors: P. Gahinet
%	 Copyright 1986-2000 The MathWorks, Inc. 
%    $Revision: 1.4 $  $Date: 2000/07/10 20:57:22 $

% REVISIT
dummy = [];

% REVISIT: simplify
HG = Editor.HG;
theta = 0:0.062831:2*pi;
Circle = line(cos(theta),sin(theta),'Color',Editor.AxesForegroundColor,...
    'Parent',HG.PlotAxes,'LineStyle',':','HitTest','off');
HG.AxisLines = [HG.AxisLines ; Circle];
Editor.HG = HG;

    
