Struct TrendLabel 

pub struct TrendLabel { /* private fields */ }

Trend Label — a discrete {−1, 0, +1} classification of the local trend from the sign of the ordinary-least-squares slope over the last period values.

slope = Σ (tᵢ − t̄)(xᵢ − x̄) / Σ (tᵢ − t̄)²      (regress price on bar index)
label = +1 if slope > 0,  −1 if slope < 0,  0 if slope == 0

The sign of the regression slope is scale-invariant — it does not depend on the nominal price level — which makes it a clean, comparable trend state across instruments. +1 marks a rising regression line, −1 a falling one, and 0 a perfectly flat window. It is the discrete companion to LinRegSlope (which returns the continuous slope): use the label when a feature pipeline wants a categorical trend direction and keys any magnitude / dead-band tuning on the raw slope itself.

Each update is O(period): the slope numerator is recomputed from the window. The denominator Σ(tᵢ − t̄)² is strictly positive for period ≥ 2, so the sign is always well-defined.

Example

use wickra_core::{Indicator, TrendLabel};

let mut indicator = TrendLabel::new(10).unwrap();
let mut last = None;
for i in 0..20 {
    last = indicator.update(100.0 + f64::from(i)); // strictly rising
}
assert_eq!(last, Some(1.0));

Implementations

impl TrendLabel

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

Construct a new Trend Label classifier.

Errors

Returns Error::InvalidPeriod if period < 2 — a slope needs at least two points.

pub const fn period(&self) -> usize

Configured period.

Trait Implementations

impl Clone for TrendLabel

fn clone(&self) -> TrendLabel

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TrendLabel

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

Formats the value using the given formatter.

impl Indicator for TrendLabel

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 the indicator is still warming up.

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.