.. _auto_curves_get_linear_fit_r2:

*GET R2 FIT TIME-HISTORY*
=========================

Computes a rolling polynomial-fit R² time-history for one or more input curves by sliding a fixed-width window along each curve. Use this worker to quantify how linearly (or how well a chosen polynomial order) a signal behaves locally over time.

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

Classification: **process**.

Tagged: ``curve_quality``, ``goodness_of_fit``, ``linear_fit``, ``polynomial_fit``, ``r2``, ``rolling_window``, ``time_history``.

Inputs
------

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

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - Base Curves
     - base_curves
     - vector
     - —
     - 
     - One or more input time-history curves (x–y vector pairs) on which the rolling R² fit will be computed; accepts multiple curves simultaneously.
   * - Window Size
     - window_size
     - string
     - 0.01
     - 
     - Width of the sliding window in the same x-axis units as the input curves (default 0.01); controls the local interval over which each polynomial fit is evaluated — smaller values capture faster local changes.
   * - Number Of Digitize Points
     - num_dig
     - string
     - 1000
     - 
     - Number of evenly-spaced digitisation points used to re-sample each curve before fitting (default 1000); the effective value is max(original point count, this value) to ensure sufficient resolution.
   * - Order
     - order
     - string
     - 1
     - 
     - Polynomial order used for the local least-squares fit when computing R² (default 1 = linear); increase to 2 or higher to measure goodness-of-fit for nonlinear trends.

Outputs
-------

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

   * - Label
     - ID
     - Type
     - Description
   * - R2 histories
     - curves_get_linear_fit_output_1
     - vector
     - One R² time-history curve per input curve, where each y-value (0–1) represents the coefficient of determination of the polynomial fit within the sliding window centred at that x-position.

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

- data.curve.transform
- data.signal_processing
- data.statistics

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

A runnable example is registered for this worker. Open the example workflow on the d3VIEW canvas: `/api/workflow/example?id=curves_get_linear_fit_r2 <https://www.d3view.com/api/workflow/example?id=curves_get_linear_fit_r2>`_

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   Auto-generated from <code>transformation</code> schema. Worker id: <code>curves_get_linear_fit_r2</code>. Schema hash: <code>a29625572b16</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
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