Struct SarExt 

pub struct SarExt { /* private fields */ }

Parabolic SAR Extended (SAREXT): Wilder’s Parabolic SAR with TA-Lib’s extended controls.

Beyond Psar it adds:

• start_value — the initial SAR. 0 auto-seeds (long, like Psar); a positive value starts a long phase at that SAR, a negative value starts a short phase at its absolute value.
• offset_on_reverse — a fractional offset applied to the new SAR on each reversal, pushing it further from price (0 disables it).
• separate long / short acceleration — independent (init, step, max) schedules for rising and falling phases.

The output is signed: a positive value during a long phase (SAR below price) and a negative value during a short phase (SAR above price), so the sign alone encodes the current trade direction.

Example

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

let mut indicator =
    SarExt::new(0.0, 0.0, 0.02, 0.02, 0.2, 0.02, 0.02, 0.2).unwrap();
let mut last = None;
for i in 0..80 {
    let base = 100.0 + f64::from(i);
    let candle =
        Candle::new(base, base + 2.0, base - 2.0, base + 1.0, 10.0, i64::from(i)).unwrap();
    last = indicator.update(candle);
}
assert!(last.is_some());

Implementations

impl SarExt

pub fn new( start_value: f64, offset_on_reverse: f64, accel_init_long: f64, accel_long: f64, accel_max_long: f64, accel_init_short: f64, accel_short: f64, accel_max_short: f64, ) -> Result<Self>

Construct an extended Parabolic SAR.

Parameters mirror TA-Lib’s SAREXT: start_value, offset_on_reverse, then the long (init, step, max) and short (init, step, max) acceleration schedules.

Errors

Returns Error::NonPositiveMultiplier if any acceleration term is non-positive or non-finite, Error::InvalidPeriod if an init exceeds its max, and Error::NonPositiveMultiplier if start_value or offset_on_reverse is non-finite or offset_on_reverse is negative.

pub fn classic() -> Self

Wilder’s defaults with no start value or reversal offset and symmetric (0.02, 0.02, 0.20) acceleration in both directions.

Trait Implementations

impl Clone for SarExt

fn clone(&self) -> SarExt

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SarExt

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

Formats the value using the given formatter.

impl Indicator for SarExt

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.