function varargout = eig_yalmip_internal(varargin)

% Author Johan Löfberg
% $Id: eig_yalmip_internal.m,v 1.6 2007-08-03 11:41:16 joloef Exp $
switch class(varargin{1})

    case 'double'
        X = varargin{1}(:);
        n = sqrt(length(X));
        X = reshape(X,n,n);
        varargout{1} = eig(X);

    case 'sdpvar' % Overloaded operator for SDPVAR objects. Pass on args and save them.

        x = varargin{1};
        y = yalmip('definemulti',mfilename,x,[size(x,1) 1]);
        varargout{1} = y;

    case 'char' % YALMIP send 'graph' when it wants the epigraph or hypograph
        %   disp('The EIG operator is not supported in optimization problems.')
        %   error

        t = varargin{2};
        X = varargin{3};
        varargout{1} = [];
        varargout{2} = struct('convexity','none','monotonicity','none','definiteness','none','model','callback');
        varargout{3} = X;

        % Inofficial way to model several nonlinear variables in
        % one call
        % varargout{2}.models = getvariables(t):getvariables(t)+length(X)-1;

    otherwise
        error('Strange type on first argument in SDPVAR/EIG');
end
