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Gap Classification

Install and import#

bash
npm install fintech-algorithms
ts
import { gapClassification } from "fintech-algorithms/price-action-and-candlesticks/candle-foundations/gap-classification";

Signature#

gapClassification(inputs)

Classifies full-range, body, or opening gaps in either direction using an explicit tick-scaled minimum distance.

Parameters#

NameTypeNotes
inputs{ previous: { open: number; high: number; low: number; close: number }; current: { open: number; high: number; low: number; close: number }; tick_size: number; minimum_gap_ticks: number }Record containing previous, current, tick_size, and minimum_gap_ticks as defined by the topic data contract.

Returns#

{ state, gap_direction, gap_type, gap_distance, threshold_distance, open_gap_up, open_gap_down, body_gap_up, body_gap_down, full_range_gap_up, full_range_gap_down, signed_open_gap, previous_close, current_open }

One classification record with state equal to gap or overlap, plus all directional checks and measured distances.

Errors#

  • When either candle is invalid, tick_size is not positive, or minimum_gap_ticks is negative — throws

Complexity: time O(1), space O(1).

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#

inputs
{
  "previous": {
    "open": 100,
    "high": 105,
    "low": 99,
    "close": 104
  },
  "current": {
    "open": 106,
    "high": 110,
    "low": 106,
    "close": 109
  },
  "tick_size": 1,
  "minimum_gap_ticks": 1
}

Call#

gapClassification(inputs)

Returns#

object with 14 fields: state, gap_direction, gap_type, gap_distance, threshold_distance, open_gap_up, open_gap_down, body_gap_up, …

{
  "state": "gap",
  "gap_direction": "up",
  "gap_type": "full-range",
  "gap_distance": 1,
  "threshold_distance": 1,
  "open_gap_up": true,
  "open_gap_down": false,
  "body_gap_up": true,
  "body_gap_down": false,
  "full_range_gap_up": true,
  "full_range_gap_down": false,
  "signed_open_gap": 2,
  "previous_close": 104,
  "current_open": 106
}

Other exports#

This module also exports calculate, shadowToBodyRatio, trendContextFilter, doji, dragonflyDoji, gravestoneDoji, marubozu, spinningTop, hammer, hangingMan, invertedHammer, shootingStar, bullishEngulfing, bearishEngulfing, bullishHarami, bearishHarami, piercingLine, darkCloudCover, tweezerTop, tweezerBottom. Every module additionally exports run as an alias of its primary function, and a meta object carrying its catalog id, domain, family, shape and article URL.

Diagrams#

Gap Classification — system map

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#

The rest of the Candle Foundations family#

  • Candle AnatomyDecomposes one candle into body, upper and lower shadow, and direction.
  • Scale-Aware Body ClassificationClassifies a candle body as long, short or doji **relative to recent bodies** rather than against a fixed threshold.
  • Shadow-to-Body RatioDecomposes one OHLC candle and reports raw and tick-stabilized shadow-to-body ratios without hiding the zero-body case.
  • Trend-Context FilterClassifies prior closes as an uptrend, downtrend, or sideways context from normalized net movement and path efficiency.