Triangle (ascending / descending / symmetrical)

Converging-trendline consolidation read from the last two swing highs and lows: ascending → +1, descending → -1, symmetrical → the sign of the latest swing.

Quick reference

Item	Value
Family	Chart Patterns
Input type	Candle (uses high, low)
Output type	f64 (+1 / -1 / 0)
Output range	{-1.0, 0.0, +1.0}
Default parameters	none (swing threshold 5%, level tolerance 3%, baked)
Warmup period	5
Interpretation	Continuation/bias of a converging range

Formula

from the last four pivots derive (high_old, high_new, low_old, low_new):
  flat  = within ±3% ; rising/falling = beyond ±3%
  ascending   : flat highs   + rising lows    → +1
  descending  : falling highs + flat lows      → -1
  symmetrical : falling highs + rising lows     → +1 if last pivot a low, else -1
otherwise → 0

The symmetrical case is directionally neutral, so its sign follows the momentum of the most recently confirmed swing. See crates/wickra-core/src/indicators/triangle.rs.

Parameters

None. Swing threshold 0.05 and level tolerance 0.03 are baked-in family constants (pattern_swing.rs). Triangle::new is infallible.

Inputs / Outputs

const _: fn(&mut wickra::Triangle, wickra::Candle) -> Option<f64> =
    <wickra::Triangle as wickra::Indicator>::update;

• Python. update((o,h,l,c,v,ts)) → float (never None); batch(open, high, low, close) → 1-D ndarray.
• Node. update(open, high, low, close) → number; batch(open, high, low, close) → number[].
• WASM. update(open, high, low, close) → number.

Warmup

warmup_period() == 5. Four confirmed pivots are required; the earliest bar that can confirm a fourth pivot is the fifth. Pinned by test accessors_and_metadata.

Edge cases

• Ascending triangle reports +1 (test ascending_triangle_is_plus_one).
• Descending triangle reports -1 (test descending_triangle_is_minus_one).
• Symmetrical ending on a low reports +1 (test symmetrical_triangle_ending_low_is_plus_one).
• Symmetrical ending on a high reports -1 (test symmetrical_triangle_ending_high_is_minus_one).
• Broadening (expanding) swings report 0.0 (test expanding_swings_are_not_a_triangle).
• reset clears state (test reset_clears_state).
• Streaming equals batch (test batch_equals_streaming).

Examples

Rust

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

fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Flat highs (120, 120), rising lows (100 → 110) → ascending triangle.
    let bars = [
        (129.87, 130.0, 129.87, 129.87),
        (100.0, 128.7, 100.0, 100.0),
        (101.0, 120.0, 101.0, 101.0),
        (110.0, 118.8, 110.0, 110.0),
        (111.1, 120.0, 111.1, 111.1),
        (108.0, 118.8, 108.0, 108.0),
    ];
    let mut pat = Triangle::new();
    let mut last = 0.0;
    for (ts, (o, h, l, c)) in bars.iter().enumerate() {
        last = pat.update(Candle::new(*o, *h, *l, *c, 1.0, ts as i64)?).unwrap();
    }
    println!("{last}"); // 1
    Ok(())
}

Python

import wickra as ta

bars = [
    (129.87, 130.0, 129.87, 129.87, 1.0, 0),
    (100.0, 128.7, 100.0, 100.0, 1.0, 1),
    (101.0, 120.0, 101.0, 101.0, 1.0, 2),
    (110.0, 118.8, 110.0, 110.0, 1.0, 3),
    (111.1, 120.0, 111.1, 111.1, 1.0, 4),
    (108.0, 118.8, 108.0, 108.0, 1.0, 5),
]
pat = ta.Triangle()
print([pat.update(b) for b in bars][-1])  # 1.0

Node

const wickra = require('wickra');
const bars = [
  [129.87, 130.0, 129.87, 129.87], [100.0, 128.7, 100.0, 100.0],
  [101.0, 120.0, 101.0, 101.0], [110.0, 118.8, 110.0, 110.0],
  [111.1, 120.0, 111.1, 111.1], [108.0, 118.8, 108.0, 108.0],
];
const pat = new wickra.Triangle();
let last = 0;
for (const [o, h, l, c] of bars) last = pat.update(o, h, l, c);
console.log(last); // 1

Streaming

pat = ta.Triangle()
for o, h, l, c, v, ts in candle_feed:
    bias = pat.update((o, h, l, c, v, ts))
    if bias > 0:
        pass  # ascending / up-biased symmetrical — lean long on breakout
    elif bias < 0:
        pass  # descending / down-biased symmetrical — lean short on breakout

Interpretation

1. Bias, not breakout. The sign encodes the structural bias of the converging range; the actual breakout (price clearing a trendline) should still confirm the trade. Ascending favours an upside break, descending a downside break.
2. Symmetrical is conditional. With no inherent direction, the symmetrical sign tracks the latest swing — re-evaluate as new pivots confirm.

Common pitfalls

• Apex proximity. Triangles lose meaning very close to the apex; the detector has no apex-distance filter, so combine with elapsed-bar context.
• One signal per confirmed pivot. The bias can flip between consecutive pivots as the legs evolve; it is a running read, not a one-shot flag.

See also

• Wedge — same-direction converging trendlines.
• RectangleRange — parallel (non-converging) range.
• Indicators-Overview — full taxonomy.