CloseVsOpen

The bar's body as a signed fraction of its open price: (close − open) / open — a scale-free, directional per-bar return.

Quick reference

Field	Value
Family	Price Statistics
Input type	Candle
Output type	f64
Output range	unbounded; signed (positive = green bar)
Default parameters	none (stateless per-bar transform)
Warmup period	1
Interpretation	+0.02 closed 2% above open; −0.02 the mirror.

Formula

CloseVsOpen = (close − open) / open

A scale-free signed measure of how far price travelled from open to close. Unlike BalanceOfPower — which normalises the body by the bar range — this normalises by the open price, so it is directly comparable to a return and stays meaningful across instruments of different nominal price. A zero open carries no scale and yields 0.

Source: crates/wickra-core/src/indicators/close_vs_open.rs.

Parameters

None. The constructor is CloseVsOpen::new().

Inputs / Outputs

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

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

Node update(open, high, low, close) / batch(open[], high[], low[], close[]); Python update(candle) / batch(open, high, low, close) → 1-D ndarray.

Warmup

warmup_period() == 1: every candle emits a value. The unit test emits_from_first_candle pins it.

Edge cases

• Reference value. (102 − 100) / 100 = 0.02; pinned by reference_value.
• Red bar. Close below open is negative; pinned by negative_body_is_negative.
• Zero open. A zero open price yields 0 (no scale); pinned by zero_open_yields_zero.
• Reset. reset() clears the emitted flag.

Examples

Rust

use wickra::{Candle, CloseVsOpen, Indicator};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut cvo = CloseVsOpen::new();
    let c = Candle::new(100.0, 103.0, 99.0, 102.0, 10.0, 0)?;
    println!("{:?}", cvo.update(c));
    Ok(())
}

Output:

Some(0.02)

Python

import wickra as ta

cvo = ta.CloseVsOpen()
print(cvo.batch([100.0], [103.0], [99.0], [102.0]))

Output:

[0.02]

Node

const ta = require('wickra');
const cvo = new ta.CloseVsOpen();
console.log(cvo.update(100, 103, 99, 102));

Output:

0.02

Interpretation

CloseVsOpen is the simplest directional bar feature: the sign tells you green vs red, the magnitude the conviction relative to price. Because it is a return, it composes cleanly into rolling statistics. For the range-normalised cousin (how the close settled within the bar's range) use BalanceOfPower; for the unsigned magnitude use BodySizePct.

Common pitfalls

• Range vs open normalisation. This divides by open, not by range; it is not bounded in [−1, 1] (a gap-and-go bar can exceed it).

References

A standard candlestick body feature; see Nison, Japanese Candlestick Charting Techniques (1991), for body interpretation.

See also

• Indicator-BalanceOfPower — body normalised by range.
• Indicator-BodySizePct — unsigned body magnitude.
• Indicators-Overview — the full taxonomy.