spectral_connectivity.transforms.tridi_inverse_iteration#

tridi_inverse_iteration(d: ndarray[tuple[int, ...], dtype[floating]], e: ndarray[tuple[int, ...], dtype[floating]], w: float, x0: ndarray[tuple[int, ...], dtype[floating]] | None = None, rtol: float = 1e-08) → ndarray[tuple[int, ...], dtype[floating]][source]#

Perform an inverse iteration.

This will find the eigenvector corresponding to the given eigenvalue in a symmetric tridiagonal system.

Note

Copied from NiTime.

Parameters:

  • d (array) – main diagonal of the tridiagonal system

  • e (array) – offdiagonal stored in e[:-1]

  • w (float) – eigenvalue of the eigenvector

  • x0 (array) – initial point to start the iteration

  • rtol (float) – tolerance for the norm of the difference of iterates

Returns:

e – The converged eigenvector

Return type:

array