GatorOscillator

Summary

GatorOscillator is RTTA's streaming Bill Williams Gator Oscillator. It plots the absolute gaps between Alligator jaw–teeth (upper histogram) and teeth–lips (lower histogram, signed negative) as a visual of whether the Alligator mouth is opening or closing.

Update API

result = rtta.GatorOscillator(
    jaw_window=13, teeth_window=8, lips_window=5,
    jaw_shift=8, teeth_shift=5, lips_shift=3,
    fillna=True,
).update(high, low)

Parameters match Alligator (same defaults for windows and shifts).

update(high, low) returns:

• upper — \(|jaw - teeth|\)
• lower — \(-|teeth - lips|\)

advance(...) updates state; last() returns the cached result.

Theory Of Operation

The Gator does not introduce new smoothers; it is a pure transform of Alligator lines. Large absolute gaps mean the mouth is open (trend). Small gaps mean the mouth is closed (sleep / consolidation). The lower series is drawn below zero by convention so a single histogram pane shows both gaps.

Williams' color rules (expansion vs contraction of each gap bar-over-bar) can be applied by the caller from successive upper/lower values; RTTA returns the raw signed magnitudes only.

Recurrence

Let \((J_t, T_t, L_t)\) be the Alligator jaw, teeth, and lips at time \(t\):

If any Alligator component is NaN, both fields are NaN.

Implementation Notes

• Implemented in src/rtta/indicator.cpp in class GatorOscillator.
• Owns an internal Alligator with identical constructor parameters.
• Result type: GatorOscillatorResult (upper, lower).
• Batch helper: batch_gator.

Reference

• StockCharts — Gator Oscillator
• Investopedia — Alligator / Gator context