Struct InverseFisherTransform 

pub struct InverseFisherTransform { /* private fields */ }

Inverse Fisher Transform of a scaled scalar input.

Compresses the input through (e^{2x} - 1) / (e^{2x} + 1) = tanh(x), the algebraic inverse of the Fisher transform. The output is bounded in [-1, +1] (saturating to exactly ±1 for |scale * input| >= ~19.06 under IEEE 754 doubles), which makes overbought/oversold thresholds at, say, ±0.5 universal across markets and timeframes — the classic use described by Ehlers in Cybernetic Analysis for Stocks and Futures (2004).

The constructor takes a scale multiplier so callers can feed raw oscillator readings (e.g. RSI in [0, 100], mapped to [-5, +5] with scale = 0.1 after a -50 shift) without writing their own scaler. Internally the indicator just computes tanh(scale * input).

Example

use wickra_core::{Indicator, InverseFisherTransform};

let mut ift = InverseFisherTransform::new(1.0).unwrap();
// Large positive input saturates to +1, large negative to -1.
assert!(ift.update(10.0).unwrap() > 0.999);
assert!(ift.update(-10.0).unwrap() < -0.999);

Implementations

impl InverseFisherTransform

pub fn new(scale: f64) -> Result<InverseFisherTransform, Error>

Construct with a multiplicative scale applied before the tanh squash.

Errors

Returns Error::InvalidPeriod if scale is not finite or non-positive.

pub const fn scale(&self) -> f64

Configured scale.

pub const fn value(&self) -> Option<f64>

Current value if available.

Trait Implementations

impl Clone for InverseFisherTransform

fn clone(&self) -> InverseFisherTransform

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for InverseFisherTransform

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

Formats the value using the given formatter.

impl Indicator for InverseFisherTransform

type Input = f64

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, input: f64) -> 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.