function [MM] = meanmaxmin (M)

a = isempty (M);

if a == 1
    
    MM = [NaN, NaN, NaN, NaN, NaN, NaN];
    
end 

if a == 0


year = M (:,1);
month = M (:,2);
day = M (:,3);
var = M (:,4);

year1 = nanmean(year);
month1 = nanmean (month);
day1 = nanmean (day);

meanvar = nanmean (var);
maxvar = nanmax (var);
minvar = nanmin (var);

MM = [year1, month1, day1, minvar, meanvar, maxvar];

end 


end