Struct LinearRegression 

pub struct LinearRegression { /* private fields */ }

Linear Regression — the endpoint of a rolling least-squares fit.

Over the last period inputs, indexed x = 0, 1, …, period − 1, it fits the line y = a + b·x by ordinary least squares and reports the line’s value at the most recent point:

b (slope)     = (n·Σxy − Σx·Σy) / (n·Σxx − (Σx)²)
a (intercept) = (Σy − b·Σx) / n
LinearReg     = a + b·(period − 1)

This is TA-Lib’s LINEARREG: a smoothed price that lags less than an SMA because it extrapolates the local trend forward to the current bar instead of averaging it away.

Each update is O(1): the Σx and Σxx terms depend only on period and are precomputed once, while Σy and Σxy are maintained incrementally as the window slides. The closed-form sliding-window identity for x = 0, 1, …, period − 1 is

new_sum_xy = old_sum_xy − old_sum_y + popped_y0    // index shift by −1
new_sum_y  = old_sum_y  − popped_y0
// then push the new value at index n−1:
sum_xy += (n − 1) · new_value
sum_y  += new_value

Example

use wickra_core::{Indicator, LinearRegression};

let mut indicator = LinearRegression::new(14).unwrap();
let mut last = None;
for i in 0..80 {
    last = indicator.update(f64::from(i));
}
assert!(last.is_some());

Implementations

impl LinearRegression

pub fn new(period: usize) -> Result<Self>

Construct a new rolling linear regression over period inputs.

Errors

Returns Error::InvalidPeriod if period < 2 — a regression line is undefined for fewer than two points.

pub const fn period(&self) -> usize

Configured period.

Trait Implementations

impl Clone for LinearRegression

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for LinearRegression

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

Formats the value using the given formatter.

impl Indicator for LinearRegression

type Input = f64

Type of one input data point (typically f64 for a price, or Candle / Tick).

type Output = f64

Type of one output value.

fn update(&mut self, value: f64) -> Option<f64>

Feed one new data point into the indicator and return the freshly computed output, or None if there is no value for this input.

fn reset(&mut self)

Reset all internal state, leaving the indicator equivalent to a freshly constructed instance with the same parameters.

fn warmup_period(&self) -> usize

Number of inputs required before the first non-None output can be produced.

fn is_ready(&self) -> bool

Whether the indicator has emitted at least one value since the last reset.

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

Stable, human-readable indicator name. Used by chaining and diagnostics.

fn batch_nan_into(&mut self, inputs: &[Self::Input], out: &mut [f64])

where Self::Input: Copy, Self::Output: Into<f64>,

Run the indicator over inputs, writing one output per input into the caller-owned out buffer (NaN where update returns None). It exists for every indicator whose output converts to an f64; the batch pipelines use it for the scalar f64 -> f64 ones.

fn batch_fast_into(&mut self, inputs: &[Self::Input], out: &mut [f64])

where Self::Input: Copy, Self::Output: Into<f64>,

Opt-in fast batch: like batch_nan_into, but an indicator with a vectorised kernel may reassociate its arithmetic to run it in SIMD lanes. Each value then agrees with the exact batch to within the tolerance the indicator documents (a few units in the last place), not bit for bit; warmup positions, NaN placement and the output length are identical. The kernels are deterministic: the same input produces the same bits on every platform, with or without SIMD hardware.