Logistic-class function

The Logistic class.

This class represents the elementwise operation $\log(1 + e^x)$. This is a special case of log(sum(exp)) that evaluates to a vector rather than to a scalar, which is useful for logistic regression. class

Logistic(x)

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

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

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

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

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

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

## S4 method for signature 'Logistic'
.grad(object, values)

Arguments

• x: An Expression or numeric constant.
• object: A Logistic object.
• values: A list of numeric values for the arguments
• idx: An index into the atom.

Methods (by generic)

• to_numeric(Logistic): Evaluates e^x elementwise, adds one, and takes the natural logarithm.
• sign_from_args(Logistic): The atom is positive.
• is_atom_convex(Logistic): The atom is convex.
• is_atom_concave(Logistic): The atom is not concave.
• is_incr(Logistic): The atom is weakly increasing.
• is_decr(Logistic): The atom is not weakly decreasing.
• .grad(Logistic): Gives the (sub/super)gradient of the atom w.r.t. each variable

Slots

• x: An Expression or numeric constant.