There is a workaround for this isssue by making a copy of the HISTFIT function and modifying the code to pass out the "pd" variable. One way to do this is to change the "h" output on the first line of the code to "varargout" and add the following to the end of the file:
h = [hh; hh1];
argout={h,pd};
if nargout > length(argout)
error('Too many output arguments.');
end
[varargout{1:nargout}]=argout{1:nargout};
