Huber-class function

The Huber class.

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

• $2M|x|-M^2$: for $|x| \geq |M|$
• $|x|^2$: for $|x| \leq |M|.$ class

Huber(x, M = 1)

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

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

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

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

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

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

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

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

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

## S4 method for signature '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.