V=rand(5,3)
W=alg_2_1(V)
W'*W
Wn=alg_2_1a(V)
Wn'*Wn
norm(Wn'*Wn-eye(3))

V1=[1 1; 0 0; 1 1+10^(-5)]
W1=alg_2_1(V1)
W1'*W1
W1n=alg_2_1a(V1)
W1n'*W1n
W1n'*W1n-eye(2)

cond(V1)
