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 % Check the number of input arguments if nargin<1, ra=[]; end; if nargin<2, rb=[]; end; if nargin<3, ang=[]; end; %if nargin==1, % error('Not enough arguments'); %end; if nargin<5, x0=[]; y0=[]; end; if nargin<6, C=[]; end if nargin<7, Nb=[]; end % set up the default values if isempty(ra),ra=1;end; if isempty(rb),rb=1;end; if isempty(ang),ang=0;end; if isempty(x0),x0=0;end; if isempty(y0),y0=0;end; if isempty(Nb),Nb=300;end; if isempty(C),C=get(gca,'colororder');end; % work on the variable sizes x0=x0(:); y0=y0(:); ra=ra(:); rb=rb(:); ang=ang(:); Nb=Nb(:); if isstr(C),C=C(:);end; if length(ra)~=length(rb), error('length(ra)~=length(rb)'); end; if length(x0)~=length(y0), error('length(x0)~=length(y0)'); end; % how many inscribed elllipses are plotted if length(ra)~=length(x0) maxk=length(ra)*length(x0); else maxk=length(ra); end; % drawing loop for k=1:maxk if length(x0)==1 xpos=x0; ypos=y0; radm=ra(k); radn=rb(k); if length(ang)==1 an=ang; else an=ang(k); end; elseif length(ra)==1 xpos=x0(k); ypos=y0(k); radm=ra; radn=rb; an=ang; elseif length(x0)==length(ra) xpos=x0(k); ypos=y0(k); radm=ra(k); radn=rb(k); an=ang(k) else rada=ra(fix((k-1)/size(x0,1))+1); radb=rb(fix((k-1)/size(x0,1))+1); an=ang(fix((k-1)/size(x0,1))+1); xpos=x0(rem(k-1,size(x0,1))+1); ypos=y0(rem(k-1,size(y0,1))+1); end; co=cos(an); si=sin(an); the=linspace(0,2*pi,Nb(rem(k-1,size(Nb,1))+1,:)+1); % x=radm*cos(the)*co-si*radn*sin(the)+xpos; % y=radm*cos(the)*si+co*radn*sin(the)+ypos; h(k)=line(radm*cos(the)*co-si*radn*sin(the)+xpos,radm*cos(the)*si+co*radn*sin(the)+ypos); set(h(k),'color',C(rem(k-1,size(C,1))+1,:)); end;