[SciPy-Dev] Least-Squares Linear Solver ( scipy.linalg.lstsq ) not optimal

[Sturla Molden]

On 20/01/15 18:47, josef.pktd at gmail.com wrote:

> rcond
>
> rcond is used to determine the effective rank of A, which is defined as
> the order of the largest leading triangular submatrix R11 in the QR
> factorization with pivoting of A, whose estimated condition number <
> 1/rcond.
>
> https://software.intel.com/en-us/node/521113

Normally rcond (reciprocal condtitioning number) means the ratio of the 
smallest singular value to the largest, i.e. a matrix is singular when 
rcond is zero. But perhaps it means something else in LAPACK?

Sturla