.. _auto_curve_linear_regression:

*FIT A LINEAR REGRESSION*
=========================

Fits a polynomial regression of selectable order (1–5) to an input curve and returns the smoothed best-fit curve. Use this worker to remove noise, extract trends, or produce a clean analytical approximation of any XY curve.

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

Classification: **process**.

Tagged: ``curve_fitting``, ``linear_regression``, ``polynomial_fit``, ``regression``, ``smoothing``, ``trend``.

Inputs
------

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

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - Reference Curve
     - curvetobeuseasreference
     - vector
     - —
     - 
     - The XY curve to fit; provide as a two-column vector (x, y). This is the only data source the regression operates on.
   * - Order
     - order
     - select
     - 1
     - 
     - Polynomial degree for the regression (1 = linear, 2 = quadratic, … 5 = quintic); defaults to 1 (linear). Higher orders capture more curvature but may overfit sparse data.
   * - Number of digitized Points
     - digitize
     - scalar
     - -1
     - 
     - Number of evenly-spaced points used to re-sample the fitted curve before output; set to -1 (default) to keep the same point spacing as the input curve.

Outputs
-------

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

   * - Label
     - ID
     - Type
     - Description
   * - Fitted Curve
     - curve_linear_fit
     - vector
     - The regression-fitted XY curve evaluated at the original (or re-sampled) x-coordinates, returned as a two-column vector matching the input domain.

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

- ai_ml.supervised.regression
- data.curve.transform

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

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

.. raw:: html

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   Auto-generated from <code>transformation</code> schema. Worker id: <code>curve_linear_regression</code>. Schema hash: <code>4137b148a3ee</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
   </p>