.. _auto_curve_get_end_of_linearity:

*GET END OF LINEARITY*
======================

Detects the end-of-linearity point on a stress-strain (or similar) curve by comparing the local slope against a reference elastic modulus and a relative deviation threshold. Use this worker to automatically identify the proportionality limit or onset of yielding from coupon test data.

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

Classification: **process**.

Tagged: ``curve_analysis``, ``elastic_modulus``, ``end_of_linearity``, ``proportionality_limit``, ``stress_strain``, ``yield_detection``.

Inputs
------

.. list-table::
   :header-rows: 1
   :widths: 20 20 20 20 20 20

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - Base Curve
     - base_curve
     - vector
     - —
     - 
     - Input XY curve (e.g. stress vs. strain) on which the end-of-linearity search is performed; supply as a two-column vector pair.
   * - emod
     - emod
     - string
     - 0
     - 
     - Reference elastic (Young's) modulus used to define the linear slope; set to 0 to let the worker estimate it automatically from the initial curve slope.
   * - threshold
     - threshold
     - string
     - 0.1
     - 
     - Relative deviation threshold (fraction, default 0.1 = 10%) above which the local tangent modulus is considered to have departed from linearity; increase to tolerate more scatter before flagging the end of linearity.
   * - xmax
     - xmax
     - string
     - 1
     - 
     - Upper x-axis limit (e.g. maximum strain) beyond which the search is not performed; default 1 — set to the expected elastic range of your data to avoid spurious detections.

Outputs
-------

.. list-table::
   :header-rows: 1
   :widths: 20 20 20 20

   * - Label
     - ID
     - Type
     - Description
   * - curve_get_end_of_linearity_output_1
     - curve_get_end_of_linearity_output_1
     - scalar
     - Scalar x-axis value (e.g. strain) at which the curve first departs from linearity by more than the specified threshold.

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

- data.curve.transform
- engineering.material.characterization

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

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

.. raw:: html

   <hr style="margin-top:2em">
   <p style="font-size:11px;color:#888">
   Auto-generated from <code>transformation</code> schema. Worker id: <code>curve_get_end_of_linearity</code>. Schema hash: <code>54a660fa4200</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
   </p>