SciPy

numpy.matrix.I

attribute

matrix.I

Returns the (multiplicative) inverse of invertible self.

Parameters:
None
Returns:
ret : matrix object

If self is non-singular, ret is such that ret * self == self * ret == np.matrix(np.eye(self[0,:].size) all return True.

Raises:
numpy.linalg.LinAlgError: Singular matrix

If self is singular.

See also

linalg.inv

Examples

>>> m = np.matrix('[1, 2; 3, 4]'); m
matrix([[1, 2],
        [3, 4]])
>>> m.getI()
matrix([[-2. ,  1. ],
        [ 1.5, -0.5]])
>>> m.getI() * m
matrix([[ 1.,  0.], # may vary
        [ 0.,  1.]])

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