.. _auto_curve_get_slope_between:

*GET THE SECANT MODULUS*
========================

Computes the secant modulus (average slope) of a curve between two specified X-axis bounds by dividing the change in Y by the change in X over that interval. Use this worker to extract a linearised stiffness or modulus value from a stress-strain, force-displacement, or any XY curve segment.

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

Classification: **process**.

Tagged: ``curve_analysis``, ``modulus``, ``secant_modulus``, ``slope``, ``stiffness``, ``stress_strain``.

Inputs
------

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

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - Input Curve
     - curve
     - vector
     - —
     - 
     - The input XY curve (e.g. stress-strain or force-displacement) from which the secant slope will be calculated; supplied as a two-column vector.
   * - X Min
     - x_min
     - scalar
     - —
     - ✓
     - Lower X-axis bound of the interval over which the secant modulus is computed; must be in the same units as the curve's X axis.
   * - X Max
     - x_max
     - scalar
     - —
     - ✓
     - Upper X-axis bound of the interval over which the secant modulus is computed; must be in the same units as the curve's X axis and greater than x_min.

Outputs
-------

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

   * - Label
     - ID
     - Type
     - Description
   * - Secant Modulus
     - slope
     - scalar
     - Scalar secant modulus (ΔY / ΔX) computed between x_min and x_max; units match the Y/X ratio of the input curve (e.g. MPa/– for stress-strain).

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_slope_between <https://www.d3view.com/api/workflow/example?id=curve_get_slope_between>`_

.. raw:: html

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   Auto-generated from <code>transformation</code> schema. Worker id: <code>curve_get_slope_between</code>. Schema hash: <code>3aa65997ac00</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
   </p>