function [MM] = validatepfunction (M)

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

ws = M (:,5);

i = find(ws < 800);
w = ws(i);
w(isnan(w)) = [];
w(any(isnan(w),2),:) = [];

MM = [year(i), month(i), day(i), hour(i), w];

end