### Sorting information dggsvd3

Posted:

**Sat Jan 14, 2017 1:41 pm**Hi,

I'm using the function dggsvd3_ in C++.

According to the documentation of the dggsvd3_ function (http://www.netlib.org/lapack/explore-ht ... 85e9baf0f2), the variable 'iwork' stores the sorting information and, as an example, it sorts the variable C (a.k.a ALPHA).

Can I use this variable to sort the other variables? For instance U, V, Q and S (a.k.a BETA)?

I'm asking this, because I used the variable iWork to sort C and S, and it works perfectly (C^2 + S^2 = I), but I can't satisfy the GSVD relation (A = U * C * [0, R] * Q^T and B = V * S * [0, R] * Q^T ) and I dont' know what to do.

Thanks in advance for any clarification.

Tiago

I'm using the function dggsvd3_ in C++.

According to the documentation of the dggsvd3_ function (http://www.netlib.org/lapack/explore-ht ... 85e9baf0f2), the variable 'iwork' stores the sorting information and, as an example, it sorts the variable C (a.k.a ALPHA).

Can I use this variable to sort the other variables? For instance U, V, Q and S (a.k.a BETA)?

I'm asking this, because I used the variable iWork to sort C and S, and it works perfectly (C^2 + S^2 = I), but I can't satisfy the GSVD relation (A = U * C * [0, R] * Q^T and B = V * S * [0, R] * Q^T ) and I dont' know what to do.

Thanks in advance for any clarification.

Tiago