Function lstsq_aux 

pub fn lstsq_aux<T, C>(
    ctx: &mut C,
    a: &Tensor<T>,
) -> Result<LstsqAuxResult<T::Real>>
where
    T: KernelLinalgScalar + Conjugate,
    T::Real: KeepCountScalar + Float,
    C: TensorLinalgContextFor<T> + TensorScalarContextFor<Standard<T::Real>>,
    C::Backend: 'static,

Compute least-squares auxiliary metadata.

This returns the singular values used for numerical rank estimation together with a batch-shaped count tensor containing the effective rank.