Struct OnNeck 

pub struct OnNeck { /* private fields */ }

On-Neck — a 2-bar bearish continuation. In a decline a long black candle is followed by a white candle that opens below the black bar’s low yet rallies only as far as the black bar’s low (the “neckline”). The feeble bounce shows sellers remain in control.

long body = |close − open| >= 0.5 * (high − low)
bar1 black & long
bar2 white, opens below bar1's low      (open2 < low1)
bar2 closes at bar1's low (the neckline) (|close2 − low1| <= 0.05 · range1)

Output is −1.0 when the pattern completes and 0.0 otherwise. On-Neck is a single-direction (bearish-only) continuation, so it never emits +1.0. The first bar always returns 0.0 because the two-bar window is not yet filled. Body and neckline thresholds follow the geometric house style rather than TA-Lib’s rolling averages. Pattern-shape check only — no trend filter is applied; combine with a trend indicator for actionable signals.

Signed ±1 encoding

This detector emits the uniform candlestick sign convention shared across the pattern family — −1.0 bearish, 0.0 no pattern — so it drops straight into a machine-learning feature matrix as a single dimension.

Example

use wickra_core::{Candle, Indicator, OnNeck};

let mut indicator = OnNeck::new();
indicator.update(Candle::new(15.0, 15.1, 9.0, 10.0, 1.0, 0).unwrap());
let out = indicator
    .update(Candle::new(7.0, 9.1, 6.9, 9.0, 1.0, 1).unwrap());
assert_eq!(out, Some(-1.0));

Implementations

impl OnNeck

pub const fn new() -> Self

Construct a new On-Neck detector.

Trait Implementations

impl Clone for OnNeck

fn clone(&self) -> OnNeck

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for OnNeck

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

Formats the value using the given formatter.

impl Default for OnNeck

fn default() -> OnNeck

Returns the “default value” for a type.

impl Indicator for OnNeck

type Input = Candle

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, candle: Candle) -> 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.