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sherman_morrison

Shermanโ€“Morrison formula.

This modifies A_inv inplace.

Parameters

  • A_inv (dict)

  • u (dict)

  • v (dict)

Examples

>>> import pprint
>>> from river import utils

>>> A_inv = {
...     (0, 0): 0.2,
...     (1, 1): 1,
...     (2, 2): 1
... }
>>> u = {0: 1, 1: 2, 2: 3}
>>> v = {0: 4}

>>> inv = sherman_morrison(A_inv, u, v)
>>> pprint.pprint(inv)
{(0, 0): 0.111111,
    (1, 0): -0.888888,
    (1, 1): 1,
    (2, 0): -1.333333,
    (2, 2): 1}

References