pyproximal.EuclideanBall#

class pyproximal.EuclideanBall(center, radius)[source]#

Euclidean ball proximal operator.

Proximal operator of the Euclidean ball: \(Eucl_{[c, r]} = \{ \mathbf{x}: ||\mathbf{x} - \mathbf{c}||_2 \leq r \}\).

Parameters
centernp.ndarray or float

Center of the ball

radiusfloat

Radius

Notes

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

Methods

__init__(center, radius)

affine_addition(v)

Affine addition

chain(g)

Chain

grad(x)

Compute gradient

postcomposition(sigma)

Postcomposition

precomposition(a, b)

Precomposition

prox(**kwargs)

proxdual(**kwargs)

Examples using pyproximal.EuclideanBall#

Basis Pursuit

Basis Pursuit