pyproximal.L0Ball#

class pyproximal.L0Ball(radius)[source]#

\(L_0\) ball proximal operator.

Proximal operator of the L0 ball: \(L0_{r} = \{ \mathbf{x}: ||\mathbf{x}||_0 \leq r \}\).

Parameters
radiusint or func, optional

Radius. This can be a constant number or a function that is called passing a counter which keeps track of how many times the prox method has been invoked before and returns a scalar radius to be used.

Notes

As the L0 ball is an indicator function, the proximal operator corresponds to its orthogonal projection (see pyproximal.projection.L0BallProj for details.

Methods

__init__(radius)

affine_addition(v)

Affine addition

chain(g)

Chain

grad(x)

Compute gradient

postcomposition(sigma)

Postcomposition

precomposition(a, b)

Precomposition

prox(*args, **kwargs)

proxdual(**kwargs)

Examples using pyproximal.L0Ball#

Group sparsity

Group sparsity

IHT, ISTA, FISTA, and TWIST for Compressive sensing

IHT, ISTA, FISTA, and TWIST for Compressive sensing