Enum Activation 

pub enum Activation {
    Identity,
    ReLU,
    Tanh,
}

Element-wise activation applied at the output of a DenseLayer.

Kept intentionally small for the v0.2.0 preview: Identity (no-op, for the terminal layer or for identity-MLP test fixtures), ReLU, and Tanh. Any more exotic activation (GELU, Swish, etc.) is a deliberate non-goal for this release.

Variants

Identity

f(x) = x.

ReLU

f(x) = max(0, x).

Tanh

f(x) = tanh(x).

Implementations

impl Activation

pub fn apply_inplace(&self, values: &mut [f64])

Apply the activation element-wise in place.

pub fn apply_scalar(&self, v: f64) -> f64

Apply the activation element-wise to a single scalar.

pub fn derivative(&self, pre_activation: f64) -> f64

Derivative f'(z) evaluated at the pre-activation z. Used by the analytical gradient paths in crate::deep_kernel::gradient.

For ReLU we follow the common convention f'(0) = 0 — this is a sub-gradient (any value in [0, 1] is admissible), but 0 is the widely adopted choice that matches finite-difference tests at most random initialisations.

pub fn name(&self) -> &'static str

Human-readable name — handy for Debug impls and error messages.

Trait Implementations

impl Clone for Activation

fn clone(&self) -> Activation

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Activation

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Hash for Activation

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Activation

fn eq(&self, other: &Activation) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Activation

impl Eq for Activation

impl StructuralPartialEq for Activation