The Logistic class.

Source: R/elementwise.R

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.

Logistic(x)

# S4 method for Logistic
to_numeric(object, values)

# S4 method for Logistic
sign_from_args(object)

# S4 method for Logistic
is_atom_convex(object)

# S4 method for Logistic
is_atom_concave(object)

# S4 method for Logistic
is_incr(object, idx)

# S4 method for Logistic
is_decr(object, idx)

# S4 method for 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.