.. _auto_curve_lankford_coefficient:

*COMPUTE LANKFORD COEFFICIENT*
==============================

Computes the Lankford coefficient (r-value) from longitudinal and transverse strain curves measured during a uniaxial tensile test. The r-value quantifies plastic anisotropy and is a key input for sheet-metal forming simulations. Use this worker when characterizing material directionality from coupon test data.

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

Classification: **process**.

Tagged: ``"``, ``-``, ``]``, ``_``, ``a``, ``c``, ``d``, ``e``.

Inputs
------

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

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - Longitudinal Strain Curve
     - longitudinal_strain_curve
     - vector
     - —
     - 
     - True longitudinal (axial) strain vs. time or displacement curve from a uniaxial tensile coupon test, supplied as an (x, y) vector; must be co-registered with the transverse strain curve.
   * - Transverse Strain Curve
     - transverse_strain_curve
     - vector
     - —
     - 
     - True transverse (width) strain vs. time or displacement curve from the same tensile coupon test, supplied as an (x, y) vector; used together with the longitudinal strain curve to compute the r-value ratio.
   * - Number Of Digitized Points
     - numberofdigitizedpoints
     - scalar
     - —
     - 
     - Integer number of evenly-spaced points used to re-digitize / resample both strain curves before the r-value calculation; leave as default (null) to use the raw curve resolution.

Outputs
-------

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

   * - Label
     - ID
     - Type
     - Description
   * - curve_lankford_coefficient_output_1
     - curve_lankford_coefficient_output_1
     - vector
     - Lankford coefficient (r-value) curve — typically r plotted as a function of strain level — returned as an (x, y) vector for downstream material calibration or reporting.

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

- data.curve.pair
- engineering.manufacturing
- engineering.material.characterization
- engineering.material.specimen

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

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

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   Auto-generated from <code>transformation</code> schema. Worker id: <code>curve_lankford_coefficient</code>. Schema hash: <code>123379f448e5</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
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