Python Sparse data Analysis Package external MRI plugin.

Note

This page is a reference documentation. It only explains the function signature, and not how to use it. Please refer to the gallery for the big picture.

mri.operators.gradient.utils.check_lipschitz_cst(f, x_shape, lipschitz_cst, max_nb_of_iter=10)[source]¶

This methods check that for random entrees the lipschitz constraint are statisfied:

||f(x)-f(y)|| < lipschitz_cst ||x-y||

Parameters

f : callable

This lipschitzien function

x_shape : tuple

Input data shape

lipschitz_cst : float

The Lischitz constant for the function f

max_nb_of_iter : int

The number of time the constraint must be satisfied

Returns

out : bool

If is True than the lipschitz_cst given in argument seems to be an upper bound of the real lipschitz constant for the function f