what's the superb argument used for in the LAPACKE_dgesvd function?

[rnickb]

I don't understand the documentation here (https://software.intel.com/en-us/node/521150); when I print it, it's all zeros. What's it useful for?

[Alexander_K_Intel3]

Hello,

The array superb is filled only if SVD failed to converge while computing diagonal matrix of singular values. The failure is indicated by positive return value of the function. For the case this array will contain superdiagonal elements of bi-diagonal matrix B, while S will contain diagonal elements, so that A = U * B * V^T.

Best regards,
Alexander