Sine Wave
Plots a sine wave and a lead-sine wave based on the cyclic phase of price movement.
Visual Example

Synthetic ideal per library logic. Generated 2026-06-25 IST via docs/generate_all_previews.py (reproducible; maps to core Next<T> implementation).
Description
The Sine Wave indicator is a technical analysis tool that plots a sine wave and a lead-sine wave based on the cyclic phase of price movement.
This indicator is primarily used for identifying key market conditions. It provides a robust signal that can be easily integrated into both simple strategies and more complex machine learning feature pipelines. Compared to its alternatives, it offers a distinct balance of responsiveness and stability.
Traders often combine this with other metrics to confirm signals and avoid false positives during sideways market regimes. It remains a standard tool for systematic trading models.
Use to confirm whether the market is in cycle or trend mode. When price follows the sine wave trade cycle reversals; when it diverges switch to trend-following.
Introduced in Rocket Science for Traders, the Sine Wave Indicator plots the sine and cosine of measured instantaneous phase. In cycling markets price tracks the sine wave; in trending markets price breaks through the lead line signaling a mode change.
QuantWave implements this indicator via the universal Next<T> trait, guaranteeing bit-identical results between Rust streaming, Python streaming, and Polars batch (.ta() / map_batches) surfaces.
Formula / Specification
Implementation (quantwave-core/src/indicators/sine_wave.rs):
[ \text{Sine} = \sin(\text{Phase}) ] [ \text{LeadSine} = \sin(\text{Phase} + 45^\circ) ]
Gold-standard parity vectors: quantwave-core/tests/gold_standard/sine_wave.json.
Parameters
| Parameter | Default | Description |
|---|---|---|
| (none) | — | No tunable parameters for this detector. |
Usage Examples
Streaming (Rust)
use quantwave_core::indicators::SINE_WAVE;
use quantwave_core::traits::Next;
let mut ind = SINE_WAVE::new(14);
for price in &prices {
let value = ind.next(price);
}
Streaming (Python)
Polars Batch (Python)
import polars as pl
import quantwave as qw
def apply_sine_wave(series: pl.Series) -> pl.Series:
ind = qw.SINE_WAVE(14)
return pl.Series([ind.next(float(v)) for v in series.to_list()])
df = (
pl.read_csv('ohlcv.csv')
.lazy()
.with_columns(
pl.col("close").map_batches(apply_sine_wave, return_dtype=pl.Float64).alias("sine_wave")
)
.collect()
)
All surfaces are bit-identical via the single Next<T> implementation and proptests.
Edge Cases & Limitations
- Recursive DSP filters require a warm-up period; first N bars may be unstable or raw-pass-through.
- Designed for cyclic/mean-reverting regimes; trending markets can produce lag or drift.
- Parameter
period(or equivalent) controls cutoff — too small adds noise, too large adds lag. - Prefer chaining with other Ehlers tools (Roofing Filter, SuperSmoother) on noisy inputs.
- Validated via proptests against gold-standard vectors where available.
- No look-ahead bias; suitable for live streaming and batch feature pipelines.
Boundary Behavior
| Condition | Behavior |
|---|---|
| Warm-up | Leading bars return NaN until warmup_bars is satisfied. |
| period > len | When period exceeds series length, output is all NaN. |
| NaN inputs | NaN in input propagates to output (NaN out). |
| Invalid params | Non-positive period or missing required params raise ValueError. |
| Empty data | Empty input returns an empty result series. |
Related Indicators & See Also
Sources & References
Primary Source: https://github.com/lavs9/quantwave/blob/main/references/Ehlers%20Papers/ROCKET%20SCIENCE%20FOR%20TRADER.pdf
Implementation: quantwave-core/src/indicators/sine_wave.rs (SINE_WAVE / SINE_WAVE_METADATA).
Parity: quantwave-core/tests/gold_standard/sine_wave.json
Provenance: Standards bulk upgrade 2026-06-25 IST — see docs/DOCUMENTATION_STANDARDS.md.