.. _auto_curve_event_detection_hold:

*DETECT EVENTS BY TRACKING A DROP AND HOLDING*
==============================================

Scans an input curve for events defined by the signal dropping to (and holding at) a specified constant value for a minimum time window. Returns the x-axis coordinate(s) at which the qualifying hold event(s) are detected. Use this worker to identify plateau regions or sustained-value events in time-history or signal data.

When to use
-----------

Classification: **process**.

Tagged: ``curve``, ``event_detection``, ``hold``, ``plateau``, ``signal``, ``time_history``, ``transformations``.

Inputs
------

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   :header-rows: 1
   :widths: 20 20 20 20 20 20

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - Curve
     - curve
     - vector
     - —
     - 
     - Input time-history or signal curve (x/y vector) to be scanned for hold events; accepts any numeric curve from an upstream worker.
   * - Hold Value
     - hold_value
     - scalar
     - 3
     - 
     - The y-value the curve must reach and remain near (within Tolerance) to qualify as an event; dimensionless scalar, default 3.
   * - Hold Window
     - hold_window
     - scalar
     - 100
     - 
     - Minimum number of consecutive x-axis samples (or time steps) for which the curve must stay within Tolerance of Hold Value to register an event; default 100 samples.
   * - Tolerance
     - tolerance
     - scalar
     - 0.01
     - 
     - Absolute tolerance band around Hold Value within which the curve is considered 'holding'; dimensionless scalar, default 0.01.
   * - Number Of Times
     - numberoftimes
     - scalar
     - 1
     - 
     - Number of qualifying hold-event occurrences to detect before stopping; set to 1 (default) to find only the first event, or higher to collect multiple occurrences.

Outputs
-------

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   :header-rows: 1
   :widths: 20 20 20 20

   * - Label
     - ID
     - Type
     - Description
   * - curve_event_detection_hold_output_1
     - curve_event_detection_hold_output_1
     - scalar
     - Scalar (or list of scalars) representing the x-axis location(s) — e.g. time or index — at which the detected hold event(s) begin on the input curve.

Disciplines
-----------

- data.curve.transform
- data.signal_processing

Runnable example
----------------

A runnable example is registered for this worker. Open the example workflow on the d3VIEW canvas: `/api/workflow/example?id=curve_event_detection_hold <https://www.d3view.com/api/workflow/example?id=curve_event_detection_hold>`_

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   Auto-generated from <code>transformation</code> schema. Worker id: <code>curve_event_detection_hold</code>. Schema hash: <code>06ebdc6155c2</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
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