LongLeggedDoji

Single-bar indecision signal. A doji with long shadows on both sides: price ranged widely up and down yet closed essentially where it opened — a tug-of-war that often precedes a turn.

Quick reference

Field	Value
Family	Candlestick Patterns
Input type	Candle
Output type	f64 — +1.0 detected (indecision), 0.0 otherwise
Output range	{0.0, +1.0}
Default parameters	none — LongLeggedDoji::new()
Warmup period	1
Interpretation	Non-directional indecision; potential turning point

Formula

range = high − low
doji       = |close − open| <= 0.1 · range
long upper = high − max(open, close) >= 0.3 · range
long lower = min(open, close) − low  >= 0.3 · range

A non-directional flag: +1.0 means "long-legged doji detected", not a bullish bias — it never emits −1.0. For the directional single-shadow variants use DragonflyDoji / GravestoneDoji. See crates/wickra-core/src/indicators/long_legged_doji.rs.

Parameters

None. Constructed with LongLeggedDoji::new().

Signed ±1 encoding

Indecision flag: +1.0 detected, 0.0 no pattern — one feature-matrix dimension (the +1.0 here marks detection, not direction).

Inputs / Outputs

use wickra::{Indicator, LongLeggedDoji, Candle};
// LongLeggedDoji: Input = Candle, Output = f64
const _: fn(&mut LongLeggedDoji, Candle) -> Option<f64> = <LongLeggedDoji as Indicator>::update;

• Always emits a value. Never None; non-matching bars return 0.0.
• Node. update(open, high, low, close) → number; batch(open, high, low, close) → Array<number>.
• Python. update(candle) → float; batch(open, high, low, close) → 1-D numpy.ndarray (0.0 on no-match).

Warmup

warmup_period() == 1 — emits from the first candle (accessors_and_metadata).

Edge cases

• One-sided shadow. A doji with only one long shadow is a dragonfly or gravestone, not long-legged, and yields 0.0 (one_sided_shadow_yields_zero).
• Not a doji. A real body yields 0.0 (non_doji_yields_zero); a flat bar yields 0.0 (zero_range_yields_zero).
• Reset. reset() clears the has-emitted flag (reset_clears_state).

Examples

Rust

use wickra::{Candle, Indicator, LongLeggedDoji};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut t = LongLeggedDoji::new();
    // Tiny body near the middle, long shadows both sides.
    println!("{:?}", t.update(Candle::new(10.0, 12.0, 8.0, 10.05, 1.0, 0)?));
    Ok(())
}

Output:

Some(1.0)

range = 4.0, body 0.05, upper shadow ≈ 1.95, lower shadow 2.0 (both > 0.3·range) — a long-legged doji. This matches long_legged_is_plus_one.

Python

import numpy as np
import wickra as ta

print(ta.LongLeggedDoji().batch(
    np.array([10.0]), np.array([12.0]), np.array([8.0]), np.array([10.05])))  # [1.]

Node

const ta = require('wickra');
const t = new ta.LongLeggedDoji();
console.log(t.update(10, 12, 8, 10.05)); // 1

Streaming

use wickra::{Candle, Indicator, LongLeggedDoji};

let mut t = LongLeggedDoji::new();
let candle_stream: Vec<wickra::Candle> = Vec::new(); // your live OHLCV candle feed
for bar in candle_stream {
    if t.update(bar) == Some(1.0) { /* indecision — watch for the resolution */ }
}

Interpretation

1. Balanced indecision. Wide two-sided shadows with a flat close show neither side won — momentum is paused.
2. Direction comes from context. As a non-directional flag, read the next bar or the prevailing trend to anticipate the resolution.
3. Reversal hint at extremes. Most meaningful after a strong move, where the pause can precede a turn.

Common pitfalls

• Reading +1.0 as bullish. It marks detection, not direction.
• Confusing with a rickshaw man. RickshawMan adds the constraint that the body sits at the centre of the range.

References

• Steve Nison, Japanese Candlestick Charting Techniques (1991).

See also

• RickshawMan — centred long-legged doji.
• Doji — the general doji detector.
• Indicators-Overview — the full taxonomy.