fabianp/scikit-learn — comment on commit 1f69abd47171a772bac118dc136188708b150e5d
File: sklearn/manifold/locally_linear.py line 153
By jakevdp:

Just a thought - another option would be to change from `sigma=0` to `sigma = 1E-15` or some other suitably small number. This might fix the singularity and allow us to recover small eigenvalues of a sparse matrix. I'm not sure how well this would work in practice, though.