The Huber class.

Source: R/elementwise.R

This class represents the elementwise Huber function, \(Huber(x, M = 1)\)

\(2M|x|-M^2\)

for \(|x| \geq |M|\)

\(|x|^2\)

for \(|x| \leq |M|.\)

Huber(x, M = 1)

# S4 method for class 'Huber'
to_numeric(object, values)

# S4 method for class 'Huber'
sign_from_args(object)

# S4 method for class 'Huber'
is_atom_convex(object)

# S4 method for class 'Huber'
is_atom_concave(object)

# S4 method for class 'Huber'
is_incr(object, idx)

# S4 method for class 'Huber'
is_decr(object, idx)

# S4 method for class 'Huber'
is_quadratic(object)

# S4 method for class 'Huber'
get_data(object)

# S4 method for class 'Huber'
validate_args(object)

# S4 method for class 'Huber'
.grad(object, values)

Arguments

x

An Expression object.

M

A positive scalar value representing the threshold. Defaults to 1.

object

A Huber object.

values

A list of numeric values for the arguments

idx

An index into the atom.

Methods (by generic)

  • to_numeric(Huber): The Huber function evaluted elementwise on the input value.

  • sign_from_args(Huber): The atom is positive.

  • is_atom_convex(Huber): The atom is convex.

  • is_atom_concave(Huber): The atom is not concave.

  • is_incr(Huber): A logical value indicating whether the atom is weakly increasing.

  • is_decr(Huber): A logical value indicating whether the atom is weakly decreasing.

  • is_quadratic(Huber): The atom is quadratic if x is affine.

  • get_data(Huber): A list containing the parameter M.

  • validate_args(Huber): Check that M is a non-negative constant.

  • .grad(Huber): Gives the (sub/super)gradient of the atom w.r.t. each variable

Slots

x

An Expression or numeric constant.

M

A positive scalar value representing the threshold. Defaults to 1.