Struct ForceIndex 

pub struct ForceIndex { /* private fields */ }

Alexander Elder’s Force Index — price change scaled by volume, EMA-smoothed.

raw_t   = (close_t − close_{t−1}) · volume_t
Force_t = EMA(raw, period)_t

The raw force is positive on an up-close and negative on a down-close, and its magnitude grows with the volume that backed the move — a big move on heavy volume registers a large force. Smoothing the raw series with an EMA gives a tradeable line; Elder’s classic period is 13. The first candle only establishes the previous close, so the first raw value appears on candle 2 and the first smoothed value on candle period + 1.

Example

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

let mut indicator = ForceIndex::new(13).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 ForceIndex

pub fn new(period: usize) -> Result<Self>

Construct a new Force Index with the given EMA smoothing period.

Errors

Returns Error::PeriodZero if period == 0.

pub const fn period(&self) -> usize

Configured smoothing period.

Trait Implementations

impl Clone for ForceIndex

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ForceIndex

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

Formats the value using the given formatter.

impl Indicator for ForceIndex

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 there is no value for this input.

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.

fn batch_nan_into(&mut self, inputs: &[Self::Input], out: &mut [f64])

where Self::Input: Copy, Self::Output: Into<f64>,

Run the indicator over inputs, writing one output per input into the caller-owned out buffer (NaN where update returns None). It exists for every indicator whose output converts to an f64; the batch pipelines use it for the scalar f64 -> f64 ones.

fn batch_fast_into(&mut self, inputs: &[Self::Input], out: &mut [f64])

where Self::Input: Copy, Self::Output: Into<f64>,

Opt-in fast batch: like batch_nan_into, but an indicator with a vectorised kernel may reassociate its arithmetic to run it in SIMD lanes. Each value then agrees with the exact batch to within the tolerance the indicator documents (a few units in the last place), not bit for bit; warmup positions, NaN placement and the output length are identical. The kernels are deterministic: the same input produces the same bits on every platform, with or without SIMD hardware.