fintech-algorithms
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Dynamic Zone Bands

Install and import#

bash
npm install fintech-algorithms
ts
import { dynamicZoneBands } from "fintech-algorithms/technical-indicators/bands-envelopes-and-squeezes/dynamic-zone-bands";

Signature#

dynamicZoneBands(input)

Dynamic Zone Bands: a quantile envelope of close -- the upper band is the 1 - q quantile of the last period closes and the lower band the q quantile -- drawn around a simple moving average.

Parameters#

NameTypeNotes
inputTopicInputbars is the required OHLCV array -- each bar carries timestamp, open, high, low, close, volume and an optional basis, strictly ordered by timestamp. From parameters this topic reads period (default 20, integer >= 2), the quantile and moving-average window, and q (default 0.2, a finite number between 0 and 0.5 inclusive), the tail fraction. period (default 20, integer >= 2) and multiplier (default 2, a finite number >= 0) are read and validated by the band family for every topic in it. multiplier is not used by this branch.

Returns#

TopicResult

series holds upper, lower and center, in that order; latest carries the last of each. All three share a warm-up of period - 1 leading nulls, so ready_at is 19 at the default period.

Warm-up#

The first `period - 1` bars (19 at the default period) positions are null. Quantiles are taken over the sorted window with linear interpolation between neighbouring closes, and emit only once the window is full.

Errors#

  • When parameters.q is not a finite number, or falls outside 0 to 0.5 — throws Error
  • When parameters.period is not an integer >= 2 — throws Error
  • When a bar is missing open, high, low, close, or volume, or one of them is not a finite number — throws Error

Complexity: time O(n * period * log period), space O(n).

Worked example#

executed Captured by running this function on the input its own test provides. Real output of real code — but not asserted against a published figure.

Input#

input
{
  "bars": [
    {
      "timestamp": "2024-01-02",
      "basis": "synthetic-unadjusted",
      "open": 100,
      "high": 101.45,
      "low": 98.695,
      "close": 100,
      "volume": 750000,
      "benchmark": 200
    },
    {
      "timestamp": "2024-01-03",
      "basis": "synthetic-unadjusted",
      "open": 101.49111452,
      "high": 103.38381693,
      "low": 100.05480022,
      "close": 101.78791214,
      "volume": 795117,
      "benchmark": 200.56326135
    },
    {
      "timestamp": "2024-01-04",
      "basis": "synthetic-unadjusted",
      "open": 102.45519048,
      "high": 104.6701838,
      "low": 100.91147007,
      "close": 102.9549389,
      "volume": 840234,
      "benchmark": 201.11020913
    }
  ],
  "parameters": {}
}

Call#

dynamicZoneBands(input)

Returns#

object with 9 fields: topic_id, title, state, ready, ready_at, series, latest, parameters, …

{
  "topic_id": "D07-F07-A10",
  "title": "Dynamic Zone Bands",
  "state": "calculated",
  "ready": true,
  "ready_at": 19,
  "series": {
    "upper": [null, null, null, null, null, null],
    "lower": [null, null, null, null, null, null],
    "center": [null, null, null, null, null, null]
  },
  "latest": {
    "upper": 106.046989472,
    "lower": 102.788143482,
    "center": 104.20055051999998
  },
  "parameters": {},
  "diagnostics": {
    "causal": true,
    "input_count": 96
  }
}

Diagrams#

Dynamic Zone Bands — article hero
Dynamic Zone Bands — concept map
Dynamic Zone Bands — decision comparison
Dynamic Zone Bands — worked example

Calculation flow#

Dynamic Zone Bands calculation flow
flowchart LR
    A["ordered OHLC or close observations, a declared centerline,"] --> B["Validate order, basis, and finite values"]
    B --> C["Apply the selected Dynamic Zone Bands convention"]
    C --> D["Emit value, readiness, and diagnostics"]
    D --> E["Interpret descriptively; test outcomes separately"]
    B -->|invalid or insufficient| X["Withhold output with a reason"]
Dynamic Zone Bands readiness and evidence states
stateDiagram-v2
    [*] --> Waiting
    Waiting --> Ready: enough valid causal observations
    Waiting --> Rejected: malformed or unsupported input
    Ready --> Calculated: selected formula applied
    Calculated --> Interpreted: diagnostic and limitation retained
    Interpreted --> Ready: next observation arrives
    Rejected --> Waiting: corrected input and deterministic reset

How it works#

This page states the contract — how to call it correctly. The article explains the concept: why it works, and where it breaks.

Read the article →

References#

  • TA-Lib function groups — see linked primary or authoritative record
  • TA-Lib C/C++ API — see linked primary or authoritative record
  • TA-Lib maintained source — see linked primary or authoritative record
  • Evidence decision
  • Level 1 evidence map

The rest of the Bands, Envelopes, and Squeezes family#