QR factorization

[Marco Caliari]

Hi all.

If you try the following with Octave 3.0.0+

octave:1> A=ones(3,4);
octave:2> [Q,R]=qr(A);

you get

octave:3> Q
Q =

   -0.57735   0.81650   0.00000
   -0.57735  -0.40825  -0.70711
   -0.57735  -0.40825   0.70711

With the other program, you get

Q =

    -0.5774   -0.5774   -0.5774
    -0.5774    0.7887   -0.2113
    -0.5774   -0.2113    0.7887

and the same R. Both the factorizations satisfy Q*R=A and Q'*Q=eye(3) and 
both the programs claim to use the LAPACK routines DGEQRF and DORGQR.
Where could be the difference?

Best regards,

Marco