%ISEMPTY Dataset overload%%	I = ISEMPTY(A,FIELD)%% INPUT%  A     Dataset%  FIELD Dataset field, default 'data'%% OUTPUT%  I     Flag, 1 if field is empty, 0 otherwise. %% DESCRIPTION% Dataset overload for ISEMPTY. This is particulary useful for% ISEMPTY(A) to test on an empty dataset, and% ISEMPTY(A,'prior') to test on an undefined PRIOR field%% SEE ALSO% DATASET, SETPRIOR, GETPRIOR