Troubleshooting

Import errors

Problem: missing runtime dependencies such as torch.

Fix: install project dependencies first.

pip install -e .

Convergence issues

Problem: iterative method does not converge or returns unstable values.

Fixes:

• Increase max_iter and tighten/relax tol as needed.

• Switch method (for example from power to svds or golub-kahan).

• For 1-norm estimation, prefer solver='lu' when memory allows.

Very large condition numbers

A very large output can be expected for nearly singular matrices. Validate with another method and inspect matrix rank/structure before treating it as an error.

GPU / device mismatch

If tensors or sparse matrices are on different devices, move data to a consistent device before estimation.