Struct vikos::model::Constant

pub struct Constant<Input> {
    pub c: f64,
    // some fields omitted
}

Models the target as a constant c

This model predicts a number. The cost function used during training decides whether this number is a mean, median, or something else.

Examples

Estimate mean

use vikos::model::Constant;
use vikos::cost::LeastSquares;
use vikos::teacher::GradientDescentAl;
use vikos::learn_history;

let features = ();
let history = [1f64, 3.0, 4.0, 7.0, 8.0, 11.0, 29.0]; //mean is 9

let cost = LeastSquares{};
let mut model = Constant::new(0.0);

let teacher = GradientDescentAl{ l0 : 0.3, t : 4.0 };
learn_history(&teacher, &cost, &mut model, history.iter().cycle().map(|&y|((),y)).take(100));
println!("{}", model.c);

Fields

c: f64

Any prediction made by this model will have the value of c

Methods

impl<I> Constant<I>

fn new(c: f64) -> Constant<I>

Creates a new Constant from a f64

Trait Implementations

impl<Input: Debug> Debug for Constant<Input>

fn fmt(&self, __arg_0: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<Input: Default> Default for Constant<Input>

fn default() -> Constant<Input>

Returns the "default value" for a type.

impl<Input: Decodable> Decodable for Constant<Input>

fn decode<__DInput: Decoder>(__arg_0: &mut __DInput) -> Result<Constant<Input>, __DInput::Error>

impl<Input: Encodable> Encodable for Constant<Input>

fn encode<__SInput: Encoder>(&self, __arg_0: &mut __SInput) -> Result<(), __SInput::Error>

impl<I> Clone for Constant<I>

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<I> Model for Constant<I>

type Input = I

Input features

fn predict(&self, _: &I) -> f64

Predicts a target for the inputs based on the internal coefficents

fn num_coefficents(&self) -> usize

The number of internal coefficents this model depends on

fn gradient(&self, coefficent: usize, _: &I) -> f64

Value predict derived by the n-th coefficent at input

fn coefficent(&mut self, coefficent: usize) -> &mut f64

Mutable reference to the n-th coefficent