Singular matrix for matched filter [manually fixed]

[zxdawn]

See spectralpython/spectral#159 for details.

[zxdawn]

Sometimes, I got this error:

  File "/home/xinz/miniconda3/envs/hyper/lib/python3.11/site-packages/spectral/algorithms/detectors.py", line 53, in __init__
    C_1 = background.inv_cov
          ^^^^^^^^^^^^^^^^^^
  File "/home/xinz/miniconda3/envs/hyper/lib/python3.11/site-packages/spectral/algorithms/algorithms.py", line 750, in inv_cov
    self._inv_cov = np.linalg.pinv(self._cov)
                    ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<__array_function__ internals>", line 200, in pinv
  File "/home/xinz/miniconda3/envs/hyper/lib/python3.11/site-packages/numpy/linalg/linalg.py", line 1983, in pinv
    u, s, vt = svd(a, full_matrices=False, hermitian=hermitian)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<__array_function__ internals>", line 200, in svd
  File "/home/xinz/miniconda3/envs/hyper/lib/python3.11/site-packages/numpy/linalg/linalg.py", line 1642, in svd
    u, s, vh = gufunc(a, signature=signature, extobj=extobj)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/xinz/miniconda3/envs/hyper/lib/python3.11/site-packages/numpy/linalg/linalg.py", line 98, in _raise_linalgerror_svd_nonconvergence
    raise LinAlgError("SVD did not converge")
numpy.linalg.LinAlgError: SVD did not converge

Updates: This is caused by all NaN values (See #28 (comment))

[zxdawn]

It's necessary to add this to the installation guide.

[zxdawn]

Added a PR to spectral: spectralpython/spectral#180