Rocr100

Rate of Change Ratio × 100 (ROCR100) — close / close[period] · 100, the momentum ratio rescaled so an unchanged price reads 100.

Quick reference

Field	Value
Family	Momentum Oscillators
Input type	f64 (single close)
Output type	f64
Output range	> 0; 100 = no change, > 100 advance, < 100 decline
Default parameters	period is required
Warmup period	period + 1
Interpretation	A percent-of-reference momentum: 105 means price is 105% of its value period bars ago.

Formula

For t >= period (after warmup):

ROCR100 = (close_t / close_{t-period}) · 100

This is Rocr scaled by 100, so the flat line moves from 1 to 100: > 100 is an advance, < 100 a decline. The × 100 rescaling makes the series read like a "percent of the reference price" and lines up visually with percentage-style oscillators. Where the reference price is zero the result is guarded to 0. See crates/wickra-core/src/indicators/rocr100.rs.

Parameters

Name	Type	Default	Valid range	Description	Source
period	usize	none	>= 1	Lookback distance in bars. period = 0 errors with Error::PeriodZero.	rocr100.rs:40

Inputs / Outputs

From crates/wickra-core/src/indicators/rocr100.rs:

use wickra::{Indicator, Rocr100};
// Rocr100: Input = f64, Output = f64
const _: fn(&mut Rocr100, f64) -> Option<f64> = <Rocr100 as Indicator>::update;

Python streams as float | None, batches as a 1-D numpy.ndarray (NaN for warmup). Node streams as number | null, batches as Array<number> with NaN placeholders.

Warmup

Rocr100::new(period).warmup_period() == period + 1 (the accessors_report_config test pins warmup_period() == 4 for period = 3). The first value is emitted at input index period — the (period + 1)-th input — once a reference price period bars back is available. The known_value_is_a_scaled_ratio test pins out[0] == None.

Edge cases

• Zero reference price. When close[period] == 0 the division is guarded and the output is 0. The unit test zero_reference_price_reports_zero pins this.
• Constant series. A flat price returns 100 for every emitted value. The unit test constant_series_yields_one_hundred pins this.
• Non-finite input. NaN / infinity inputs are ignored: they leave the window untouched and the last computed value is returned. The unit test non_finite_input_holds_last pins this.
• Reset. r.reset() clears the window and last value. The unit test reset_clears_state pins this.

Examples

Rust

use wickra::{BatchExt, Indicator, Rocr100};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut r = Rocr100::new(1)?;
    let out: Vec<Option<f64>> = r.batch(&[10.0, 11.0]);
    println!("{:?}", out);
    Ok(())
}

Output:

[None, Some(110.0)]

Period 1 over [10, 11]: 11 / 10 · 100 = 110. This matches the known_value_is_a_scaled_ratio unit test in crates/wickra-core/src/indicators/rocr100.rs.

Python

import numpy as np
import wickra as ta

r = ta.Rocr100(1)
print(r.batch(np.array([10.0, 11.0])))

Output:

[ nan 110.]

Node

const ta = require('wickra');
const r = new ta.Rocr100(1);
for (const x of [10, 11]) console.log(x, '->', r.update(x));

Output:

10 -> null
11 -> 110

Interpretation

Rocr100 is identical in shape to Rocr but reads on a 100-centred scale, which many traders find more intuitive: 110 is "price is 110% of where it was", 90 is "90%". The 100 line is the flat reference; crossings mark a return to the lookback price. As with Rocr, the scale is multiplicative and asymmetric — a halving reads 50, a doubling 200.

Pick whichever of Rocp / Rocr / Rocr100 matches the scale your downstream logic expects; they carry identical information.

Common pitfalls

• Reading it as a percentage change. ROCR100 is the ratio ×100, not the change ×100. A +10% move reads 110, not 10; the percentage change is ROCR100 − 100 (here 10), which is Roc.
• Asymmetry around 100. Equal up/down moves are not symmetric on this scale (+10% → 110, −10% → 90, but the geometric pivot is 100).

References

The Rate of Change Ratio ×100 is TA-Lib's ROCR100 function.

See also

• Indicator-Rocr — the same ratio centred on 1.
• Indicator-Rocp — the fractional form.
• Indicator-Roc — the percentage-change form (ROCR100 − 100).
• Indicators-Overview — the full taxonomy.