Struct ThreeStarsInSouth 

pub struct ThreeStarsInSouth { /* private fields */ }

Three Stars in the South — a rare 3-bar bullish reversal: three shrinking red candles where each session carves out a higher low and contracts toward a tiny black marubozu, signalling exhausted selling at the bottom of a decline.

tol           = tolerance * max(|bar3.high|, |bar3.low|)
all three red                                        (close < open)
bar1 long lower shadow   (bar1.close − bar1.low) >= (bar1.open − bar1.close)
bar2 opens inside bar1's body, higher low, smaller body, closes above bar1.close
bar3 small black marubozu (upper & lower shadow <= tol) inside bar2's range

Output is +1.0 when the pattern completes and 0.0 otherwise. Three Stars in the South is a single-direction (bullish-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 bullish, 0.0 no pattern — so it drops straight into a machine-learning feature matrix as a single dimension.

Example

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

let mut indicator = ThreeStarsInSouth::new();
indicator.update(Candle::new(20.0, 20.1, 8.0, 15.0, 1.0, 0).unwrap());
indicator.update(Candle::new(18.0, 18.1, 12.0, 16.0, 1.0, 1).unwrap());
let out = indicator
    .update(Candle::new(15.0, 15.0, 14.0, 14.0, 1.0, 2).unwrap());
assert_eq!(out, Some(1.0));

Implementations

impl ThreeStarsInSouth

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 ThreeStarsInSouth

fn clone(&self) -> ThreeStarsInSouth

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ThreeStarsInSouth

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

Formats the value using the given formatter.

impl Default for ThreeStarsInSouth

fn default() -> Self

Returns the “default value” for a type.

impl Indicator for ThreeStarsInSouth

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.