Struct DoubleTopBottom 

pub struct DoubleTopBottom { /* private fields */ }

Double Top / Double Bottom — a two-peak (or two-trough) reversal pattern.

The detector tracks confirmed swing pivots (a non-repainting percent-threshold zig-zag, [SWING_THRESHOLD] = 5%). A pattern is recognised on the bar that confirms the second matching extreme:

double top    : … High₁ , Low , High₂   with  High₁ ≈ High₂   → -1 (bearish)
double bottom : … Low₁  , High , Low₂    with  Low₁  ≈ Low₂    → +1 (bullish)

Two extremes count as the same level when they are within [LEVEL_TOLERANCE] (3%) of each other. Because pivots strictly alternate high/low, the trough between the twin tops (or the peak between the twin bottoms) is guaranteed to sit beyond both, so no extra separation check is needed.

Output is +1.0 for a double bottom, -1.0 for a double top, and 0.0 on every other bar (including warmup and bars that confirm a pivot which does not complete the pattern). Like the candlestick family this detector never returns None.

Example

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

let mut indicator = DoubleTopBottom::new();
for (i, &(high, low)) in [
    (100.0, 99.5),
    (120.0, 119.5),
    (110.0, 100.0), // confirms the first top at 120
    (120.0, 119.0), // confirms the trough at 100
    (115.0, 110.0), // confirms the second top at 120 → double top
]
.iter()
.enumerate()
{
    let c = Candle::new(low, high, low, low, 1.0, i as i64).unwrap();
    let signal = indicator.update(c).unwrap();
    if i == 4 {
        assert_eq!(signal, -1.0);
    }
}

Implementations

impl DoubleTopBottom

pub const fn new() -> Self

Construct a new Double Top / Double Bottom detector.

Trait Implementations

impl Clone for DoubleTopBottom

fn clone(&self) -> DoubleTopBottom

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DoubleTopBottom

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

Formats the value using the given formatter.

impl Default for DoubleTopBottom

fn default() -> Self

Returns the “default value” for a type.

impl Indicator for DoubleTopBottom

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.