Enum Loss 

pub enum Loss {
    Misclassification,
    Custom {
        function: Box<dyn LeafLoss>,
        input: LossInput,
    },
}

The loss a search minimises.

Variants

Misclassification

Misclassification: the number of instances not of the majority class.

Custom

A caller’s loss, with the input it asks for.

Fields

function: Box<dyn LeafLoss>

input: LossInput

Implementations

impl Loss

pub fn custom(function: Box<dyn LeafLoss>, input: LossInput) -> Self

A caller’s loss.

pub fn is_misclassification(&self) -> bool

Whether this is the built-in misclassification.

pub fn uses_indices(&self) -> bool

Whether the loss reads instance ids rather than class counts.

pub fn leaf( &self, class_counts: &[usize], indices: impl FnOnce() -> Vec<usize>, ) -> (Cost, usize)

The cost of a leaf with these class counts and instance ids. indices is only called for a loss that reads them.

Trait Implementations

impl Default for Loss

fn default() -> Loss

Returns the “default value” for a type.