Psychological Line
Install and import#
npm install fintech-algorithmsimport { psychologicalLine } from "fintech-algorithms/technical-indicators/momentum/psychological-line";Signature#
psychologicalLine(input)The percentage of the last period bars that closed above the previous close, a plain count of how one-sided recent sentiment has been.
Parameters#
| Name | Type | Notes |
|---|---|---|
input | TopicInput | bars is a chronological array of OHLCV rows, each with a non-empty timestamp plus finite open, high, low, close and volume. From parameters this topic reads period (integer >= 2, default 14), the count window. The preamble also validates fast_period (default 5) and slow_period (default 34) before branching, so a bad value for either throws even though this topic does not use them. |
Returns#
TopicResult
series and latest carry one key, value, equal to 100 times the number of up-closes in the trailing window divided by period. A null warm-up prefix precedes the first reading.
Warm-up#
The first period bars (14 by default) positions are null. The first bar has no prior close to compare against, so the first complete window ends at index period rather than period - 1; ready_at is 14 on the canonical fixture.
Errors#
- When
periodis not an integer >= 2 — throws Error - When a bar's
timestampis missing or not a non-empty string — throws Error
Complexity: time O(n * 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#
{
"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#
psychologicalLine(input)Returns#
object with 9 fields: topic_id, title, state, ready, ready_at, series, latest, parameters, …
{
"topic_id": "D07-F03-A28",
"title": "Psychological Line",
"state": "calculated",
"ready": true,
"ready_at": 14,
"series": {
"value": [null, null, null, null, null, null]
},
"latest": {
"value": 28.571428571428573
},
"parameters": {},
"diagnostics": {
"causal": true,
"input_count": 96
}
}Diagrams#
Calculation flow#
Psychological Line 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 Psychological Line 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"]
Psychological Line 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.
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