Struct IdenticalThreeCrows 

pub struct IdenticalThreeCrows { /* private fields */ }

Identical Three Crows — a 3-bar bearish reversal: three consecutive red candles with steadily lower closes where each candle opens at (or very near) the prior candle’s close, so the bodies stack in an identical staircase.

tol_n         = tolerance * max(|open|, |prev.close|)
all three red                              (close < open)
declining closes                           (bar2.close < bar1.close, bar3.close < bar2.close)
bar2 opens at bar1's close                 (|bar2.open − bar1.close| <= tol_2)
bar3 opens at bar2's close                 (|bar3.open − bar2.close| <= tol_3)

Output is −1.0 when the pattern completes and 0.0 otherwise. Identical Three Crows is a single-direction (bearish-only) pattern, so it never emits +1.0. The first two bars always return 0.0 because the three-bar window is not yet filled. tolerance defaults to 0.001 (10 bps relative) and must lie in [0, 1). 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, IdenticalThreeCrows, Indicator};

let mut indicator = IdenticalThreeCrows::new();
indicator.update(Candle::new(13.0, 13.1, 11.9, 12.0, 1.0, 0).unwrap());
indicator.update(Candle::new(12.0, 12.1, 10.9, 11.0, 1.0, 1).unwrap());
let out = indicator
    .update(Candle::new(11.0, 11.1, 9.9, 10.0, 1.0, 2).unwrap());
assert_eq!(out, Some(-1.0));

Implementations

impl IdenticalThreeCrows

pub const fn new() -> Self

Construct a detector with the default relative tolerance (1e-3).

pub fn with_tolerance(tolerance: f64) -> Result<Self>

Construct a detector with a custom relative tolerance.

tolerance must lie in [0, 1).

pub fn tolerance(&self) -> f64

Configured relative tolerance.

Trait Implementations

impl Clone for IdenticalThreeCrows

fn clone(&self) -> IdenticalThreeCrows

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for IdenticalThreeCrows

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

Formats the value using the given formatter.

impl Default for IdenticalThreeCrows

fn default() -> Self

Returns the “default value” for a type.

impl Indicator for IdenticalThreeCrows

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.