kepler.m

nonlinear eq routines in matlab

function varargout = kepler_f(E)
%
% 
%
%  [y]    = kepler(E)  returns the function value y= M - E + e sin(E),
%  [y,yp] = kepler(E)  returns the function value in y and 
%                       the derivative in yp
%
%  Matthias Heinkenschloss
%  Department of Computational and Applied Mathematics
%  Rice University
%  March 29, 2001
%

M = 1;
e = 0.5;
% return the function value
varargout{1} = M - E + e*sin(E);
if( nargout > 1 )
  % return the derivative as the second argument
  varargout{2} = -1 + e*cos(E);
end