.. _auto_curve_add_noise:

*ADD NOISE TO CURVE*
====================

Adds synthetic noise to a clean input curve to simulate measurement variability or test robustness. Supports four noise modes — Gaussian, uniform, spike (sparse outliers), and periodic (sinusoidal) — with configurable amplitude and optional random seed for reproducibility.

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

Classification: **process**.

Tagged: ``augmentation``, ``curve``, ``gaussian``, ``noise``, ``periodic``, ``reproducibility``, ``seed``, ``signal``.

Inputs
------

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

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - Curve
     - curve
     - vector
     - —
     - ✓
     - The clean input curve (X/Y vector) to which noise will be added; must be provided as a d3VIEW curve object.
   * - Noise Type
     - noise_type
     - list
     - gaussian
     - 
     - Noise model to apply: 'gaussian' (per-point normal random noise), 'uniform' (per-point uniform random noise), 'spike' (sparse high-magnitude outliers), or 'periodic' (sinusoidal overlay); defaults to 'gaussian'.
   * - Amplitude (fraction of Y range)
     - amplitude
     - scalar
     - 0.05
     - 
     - Noise amplitude expressed as a fraction of the curve's Y-range (dimensionless, 0–1); interpretation varies by type — standard deviation for Gaussian, half-width for uniform, 1σ scale for spike, sine amplitude for periodic; default 0.05.
   * - Random Seed (optional)
     - seed
     - scalar
     - —
     - 
     - Optional integer random seed for reproducible noise draws; leave blank to generate a fresh random sequence on every run.
   * - Spike Fraction (spike type only)
     - spike_fraction
     - scalar
     - 0.05
     - 
     - Fraction of curve points (0–1) that receive a spike perturbation; only used when Noise Type is 'spike'; default 0.05 (5 % of points).
   * - Periodic Cycles (periodic type only)
     - periodic_cycles
     - scalar
     - 10
     - 
     - Number of sine cycles across the X range. Only used when Noise Type = periodic.

Outputs
-------

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

   * - Label
     - ID
     - Type
     - Description
   * - curve_add_noise_output_1
     - curve_add_noise_output_1
     - vector
     - Noisy output curve (X/Y vector) with the same X coordinates as the input and Y values perturbed according to the selected noise type and amplitude.

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

- data.curve.transform
- data.signal_processing

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

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

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   Auto-generated from <code>transformation</code> schema. Worker id: <code>curve_add_noise</code>. Schema hash: <code>46f8c39e7fe4</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
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