[a,~,c] = unique(values,'stable');
d = reshape(c,[],2);
dm = min(d(:,2));
ny = accumarray(d(:,2) - dm + 1,1);
[a1,~,c1] = unique(d,'rows');
P = accumarray(c1,1)./ny(a1(:,2) - dm + 1);
with use table:
T1 = table(values(:,1),values(:,2),'v',{'weather','par'});
[g,name] = findgroups(T1);
[g1,name1] = findgroups(T1.par);
[~,ii] = ismember(name.par,name1);
ny = accumarray(g1,1);
P = [name,table(accumarray(g,1)./ny(ii),'v',{'probability'})];
