You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: isnan.m
    path of file: ./repos/chebfun/@deltafun
    
    the code of the file until where you have to start completion: function out = isnan(f)
%ISNAN   Test if the FUNPART of a DELTAFUN has any NaN values.
%   ISNAN(F) returns TRUE if the FUNPART of F has any NaN values and 
%   FALSE otherwise.
%
% See also ISFINITE, ISINF.

% Copyright 2017 by The University of Oxford and The Chebfun Developers. 
% See http://www.chebfun.org/ for Chebfun information.


    
function out = isnan(f)
%ISNAN   Test if the FUNPART of a DELTAFUN has any NaN values.
%   ISNAN(F) returns TRUE if the FUNPART of F has any NaN values and 
%   FALSE otherwise.
%
% See also ISFINITE, ISINF.

% Copyright 2017 by The University of Oxford and The Chebfun Developers. 
% See http://www.chebfun.org/ for Chebfun information.

% Check if any values are NaN:
out = isnan(f.funPart);

end