skglm.penalties.L0_5#

class skglm.penalties.L0_5(alpha)[source]#

`ell_(0.5)` non-convex quasi-norm penalty.

__init__(alpha)[source]#

Methods

__init__(alpha)

derivative(w)

Compute the element-wise derivative.

generalized_support(w)

Return a mask with non-zero coefficients.

get_spec()

Specify the numba types of the class attributes.

is_penalized(n_features)

Return a binary mask with the penalized features.

params_to_dict()

Get the parameters to initialize an instance of the class.

prox_1d(value, stepsize, j)

Compute the proximal operator of L0_5.

subdiff_distance(w, grad, ws)

Compute distance of negative gradient to the subdifferential at w.

value(w)

Compute the value of L0_5 at w.