Absolute Price Oscillator

Install and import#

npm install fintech-algorithms

import { absolutePriceOscillator } from "fintech-algorithms/technical-indicators/momentum/absolute-price-oscillator";

Signature#

absolutePriceOscillator(input)

Subtracts a slow EMA of close from a fast EMA of close, leaving the momentum spread in price units rather than as a percentage.

Parameters#

Returns#

TopicResult

series and latest carry one key, value, holding the fast EMA minus the slow EMA at each bar. Both EMAs seed from the simple average of their first full window, so the series opens with a null warm-up prefix.

Warm-up#

The first slow_period - 1 bars (33 with the default 34) positions are null. value stays null until the slow EMA is seeded, which happens at index slow_period - 1; ready_at is 33 on the canonical fixture.

Errors#

• When slow_period is not an integer greater than fast_period — throws Error
• When a bar's high is below its open, close, or low — throws Error

Complexity: time O(n), 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#

{
  "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#

absolutePriceOscillator(input)

Returns#

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

{
  "topic_id": "D07-F03-A09",
  "title": "Absolute Price Oscillator",
  "state": "calculated",
  "ready": true,
  "ready_at": 33,
  "series": {
    "value": [null, null, null, null, null, null]
  },
  "latest": {
    "value": -2.0125312416213603
  },
  "parameters": {},
  "diagnostics": {
    "causal": true,
    "input_count": 96
  }
}

Diagrams#

Calculation flow#

flowchart LR
    A["an ordered price or OHLC series, declared lookbacks, smoot"] --> B["Validate order, basis, and finite values"]
    B --> C["Apply the selected Absolute Price Oscillator 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"]

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 Momentum family#

• Relative Strength Index (RSI)Relative strength index: Wilder-smoothed average gain over average loss, mapped to 0–100.
• Stochastic OscillatorWhere the close sits within the high–low range of the lookback, expressed as 0–100, then smoothed twice.
• Stochastic RSIThe stochastic formula applied to RSI rather than to price — a second-order indicator that measures where RSI sits within its o…
• Williams %RWhere the close sits within the lookback's high–low range, on a −100…0 scale.
• Commodity Channel Index (CCI)Commodity channel index: the typical price's distance from its moving average, scaled by mean absolute deviation.
• Ultimate OscillatorWeighted buying pressure across three lookbacks at once, which is what makes it less sensitive to the choice of any single peri…
• True Strength Index (TSI)True strength index: price change smoothed twice, divided by absolute price change smoothed the same way.
• Connors RSIThe average of three components: RSI of price, RSI of the up/down streak length, and the percentile rank of the latest return.
• Rate-of-Change Variants (ROC, ROCP, and ROCR)Expresses the same period-bar price ratio three ways: as a percentage, as a proportion, and as the raw ratio.
• Price Momentum (MOM)The plain price difference between the current close and the close period bars earlier.
• Chande Momentum OscillatorCompares summed up-closes against summed down-closes over a period window and scales the imbalance to a -100..100 range.
• Awesome OscillatorSubtracts a 34-period simple average of the median price from a 5-period one, measuring the gap between short and long swing mo…
• Accelerator OscillatorSubtracts a 5-period simple average of the Awesome Oscillator from the oscillator itself, isolating the change in momentum rath…
• TRIXThe one-bar percentage rate of change of a triple-smoothed EMA of close, which strips most short-cycle noise before measuring…
• Stochastic Momentum IndexMeasures where close sits relative to the midpoint of the period high-low range, then double-smooths both the distance and …
• Relative Vigor IndexDivides the period average of the candle body by the period average of the candle range, reading closing vigour relative to…
• Relative Momentum IndexAn RSI-shaped 0..100 reading built on the change over momentum_lag bars instead of the one-bar change, Wilder-smoothed over `…
• Fisher TransformRescales close to its position within the period high-low range of closes, clamps it just inside -1..1, and applies the Fis…
• Inverse Fisher TransformSquashes a scaled one-bar close change into -1..1 with the inverse Fisher transform, which is the hyperbolic tangent of the sca…
• Schaff Trend CycleRuns the MACD line through two stochastic passes, each followed by a 3-period EMA, turning a trend measure into a 0..100 cycle …
• Quantitative Qualitative Estimation (QQE)Smooths a Wilder RSI with a 5-period EMA and wraps it in a volatility band derived from a double Wilder-smoothed average of the…
• WaveTrend OscillatorBuilds a CCI-style channel index from the typical price against its own 10-period EMA and mean deviation, then smooths it into …
• Know Sure Thing (KST)Weights four smoothed rate-of-change readings taken over different lookbacks into a single momentum line, with a simple-average…
• Chande Forecast OscillatorFits a least-squares line to the last period closes and reports how far the actual close sits from that line's endpoint, as a…
• Detrended Price OscillatorRemoves the trend by subtracting the current period simple average from a close shifted back half that window, leaving the sh…
• Balance of PowerDivides each candle's body by its full range, giving a per-bar -1..1 reading of how much of the session's travel the close mana…
• Psychological LineThe percentage of the last period bars that closed above the previous close, a plain count of how one-sided recent sentiment …
• Pretty Good OscillatorExpresses the gap between close and its period simple average in units of average true range, so readings stay comparable a…
• Price Momentum OscillatorSmooths a heavily scaled one-bar rate of change through two successive EMAs, then adds a third EMA as the signal line.