function b = isint(x)
%ISINT  True for integers.
%
%   ISINT(X) returns 1's where the elements of X are integers and 0's where
%   they are not.  For example, ISINT([ 2e9 pi 3+5i NaN ]) is [ 1 0 1 0 ].
%
%   See also ISEVEN, ISODD.

%   Author:      Peter John Acklam
%   Time-stamp:  2003-04-12 14:30:59 +0200
%   E-mail:      pjacklam@online.no
%   URL:         http://home.online.no/~pjacklam

   error(nargchk(1, 1, nargin));
   if ~isnumeric(x)
      error('Argument must be a numeric array.');
   end

   cls = class(x);                      % class of input argument
   if isempty(x)
      b = feval(cls, x);                % return empty array of same class
   else
      switch cls
         case 'double'
            b = x == round(x);
         case 'single'
            % "mod" is not defined for class "single"; so convert input to
            % double, compare, and convert back
            d = double(x);
            b = single(d == round(d));
         case {'int8', 'int16', 'int32', 'int64', ...
               'uint8', 'uint16', 'uint32', 'uint64'}
            % return an array of ones of the same class as input argument
            b = logical(repmat(feval(cls, 1), size(x)));
         otherwise
            error('Argument is of unrecognized class.');
      end
   end