SinglePrints

The count of price levels touched by exactly one bar — Market Profile "single prints" that mark fast, low-acceptance moves.

Quick reference

Field	Value
Family	Market Profile
Input type	Candle (high / low)
Output type	f64 (count)
Output range	[0, bins]
Default parameters	(period = 20, bins = 24) (Python)
Warmup period	period
Interpretation	High = fast/trending (low rotation); low = balanced range.

Formula

for each of `bins` price levels over the last `period` candles:
  touches = number of bars whose high-low range covers that level
SinglePrints = count of levels with touches == 1

A "single print" is a price the market traded through so fast that only one time-period printed there — a footprint of an aggressive, one-sided move with little two-way trade. Single prints often act as S/R on a retest and mark the edges of rapid moves. The count gauges how much of the range was traversed without acceptance. Source: crates/wickra-core/src/indicators/single_prints.rs.

Parameters

Name	Type	Default	Valid range	Source	Description
period	usize	20 (Python)	>= 1	single_prints.rs:56	Rolling profile window.
bins	usize	24 (Python)	>= 1	single_prints.rs:56	Price levels. 0 for either errors with Error::PeriodZero.

params() returns (period, bins); value returns the current count if ready.

Inputs / Outputs

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

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

A Candle in, an Option<f64> out (a count). Python update(candle) / batch(high, low); Node update(high, low) / batch(...).

Warmup

warmup_period() == period. The profile window must fill first (first_emission_at_warmup_period pins this).

Edge cases

• Flat range → 0. A zero-span window has no single prints (flat_range_has_no_single_prints pins this).
• Ramp → many. A one-directional ramp visits most levels once (ramp_has_many_single_prints pins this).
• Non-negative. The count is >= 0 (output_non_negative pins this).
• Finiteness. Candle::new rejects non-finite fields, so no in-method guard is needed.
• Reset. s.reset() clears the window and the last value (reset_clears_state).

Examples

Rust

use wickra::{BatchExt, Candle, Indicator, SinglePrints};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut s = SinglePrints::new(10, 24)?;
    let candles: Vec<Candle> = (0..10)
        .map(|i| { let b = 100.0 + f64::from(i); Candle::new(b, b + 0.5, b - 0.5, b, 1_000.0, 0).unwrap() })
        .collect();
    println!("single prints: {}", s.batch(&candles).last().unwrap().unwrap());
    Ok(())
}

Python

import numpy as np
import wickra as ta

s = ta.SinglePrints(20, 24)
high = np.arange(40.0) + 100.5; low = np.arange(40.0) + 99.5
print(s.batch(high, low)[-1])  # number of single-print levels

Node

const ta = require('wickra');
const s = new ta.SinglePrints(20, 24);
console.log('warmupPeriod:', s.warmupPeriod()); // 20

Streaming

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

let mut s = SinglePrints::new(20, 24).unwrap();
let feed: Vec<Candle> = Vec::new(); // your live stream
for candle in feed {
    if let Some(n) = s.update(candle) {
        // n high -> fast, low-rotation move; expect retests of the single-print zone
    }
}

Streaming update and batch are equivalent tick-for-tick (batch_equals_streaming pins this).

Interpretation

1. Move quality. Many single prints = a fast, emotional move; expect it to be revisited ("repaired") later.
2. Support/resistance. The single-print zone often halts a retest — a fade or continuation decision point.
3. Regime. A collapsing single-print count signals the market is balancing and accepting price.

Common pitfalls

• TPO vs. range. This counts touches by bar range, a practical proxy for the classic TPO single print.
• Bin resolution. Finer bins create more single prints; keep bins consistent when comparing.
• Session framing. Set period to a session for traditional reads.

References

Steidlmayer, J. P. — Market Profile; Dalton, J. F. (1993), Mind Over Markets (single prints and range extension).

See also

• Indicator-TpoProfile — the time-price-opportunity profile.
• Indicator-HighLowVolumeNodes — HVN/LVN levels.
• Indicator-ValueArea — the value area.
• Indicators-Overview — the full taxonomy.