how can I calculate L-moment with different data length.

for i=1:500
    for j=1
        b0(j,:,i)=D(j,:,i)/19;
        for k=1:18
            b1(j,k,i)=(D(j,k,i)*(19-k))/(19*18);
            for m= 1:17
                b2(j,m,i)=(D(j,m,i)*(19-m)*(19-m-1))/(19*18*17);
                for n=1:16
                    b3(j,n,i)=(D(j,n,i)*(19-n)*(19-n-1)*(19-n-2))/(19*18*17*16);
                end
            end
        end
    end
end

[KSSV]

What exactly is your question? What is code for? Do you face any error with code?