Ellipse.m

 function h=ellipse(ra,rb,ang,x0,y0,C,Nb)
 % Ellipse adds ellipses to the current plot
 %
 % ELLIPSE(ra,rb,ang,x0,y0) adds an ellipse with semimajor axis of ra,
 % a semimajor axis of radius rb, a semimajor axis of ang, centered at
 % the point x0,y0.
 %
 % The length of ra, rb, and ang should be the same. 
 % If ra is a vector of length L and x0,y0 scalars, L ellipses
 % are added at point x0,y0.
 % If ra is a scalar and x0,y0 vectors of length M, M ellipse are with the same 
 % radii are added at the points x0,y0.
 % If ra, x0, y0 are vectors of the same length L=M, M ellipses are added.
 % If ra is a vector of length L and x0, y0 are  vectors of length
 % M~=L, L*M ellipses are added, at each point x0,y0, L ellipses of radius ra.
 %
 % ELLIPSE(ra,rb,ang,x0,y0,C)
 % adds ellipses of color C. C may be a string ('r','b',...) or the RGB value. 
 % If no color is specified, it makes automatic use of the colors specified by 
 % the axes ColorOrder property. For several circles C may be a vector.
 %
 % ELLIPSE(ra,rb,ang,x0,y0,C,Nb), Nb specifies the number of points
 % used to draw the ellipse. The default value is 300. Nb may be used
 % for each ellipse individually.
 %
 % h=ELLIPSE(...) returns the handles to the ellipses.
 %
 % as a sample of how ellipse works, the following produces a red ellipse
 % tipped up at a 45 deg axis from the x axis
 % ellipse(1,2,pi/8,1,1,'r')
 %
 % note that if ra=rb, ELLIPSE plots a circle
 %

% written by D.G. Long, Brigham Young University, based on the % CIRCLES.m original % written by Peter Blattner, Institute of Microtechnology, University of % Neuchatel, Switzerland, blattner@imt.unine.ch