.. _auto_curves_multiply_pairs:

*MULTIPLY PAIRS OF CURVES*
==========================

Multiplies two curve groups element-wise (pair by pair), interpolating onto a common x-axis before multiplication. Use this worker when you need to scale or modulate one set of curves by another, such as applying a ratio or weighting curve to a response curve.

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

Classification: **process**.

Tagged: ``curve_math``, ``curve_pairs``, ``element_wise``, ``interpolation``, ``multiply``, ``scaling``.

Inputs
------

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

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - Curve 1
     - curve_group1
     - vector
     - —
     - 
     - First curve group (the curves to be scaled/modulated); accepts one or more curves — each curve is paired in order with the corresponding curve from Curve Group 2.
   * - Curve 2
     - curve_group2
     - vector
     - —
     - 
     - Second curve group (the multiplier/ratio curves); must contain the same number of curves as Curve Group 1, paired by index.
   * - Points Type
     - points_type
     - scalar
     - unique
     - 
     - Controls which x-axis points are used after interpolation: 'unique' merges all x-points from both curves (default), 'first_curve' retains only the x-points of the first curve.
   * - Extrapolate
     - extrapolate
     - scalar
     - no
     - 
     - Determines how y-values are handled when x falls outside the defined range of a curve: 'no' (default) assigns 0.0, 'yes' extrapolates linearly, 'constant' holds the last value, 'join' concatenates curves after scaling, 'clip' truncates at the last ratio value, 'stretch' rescales the ratio curve to match the x-extent of the first curve.
   * - Start X
     - start_x
     - text
     - —
     - 
     - Optional lower x-bound for the multiplication operation; leave null to use the natural start of the curves.
   * - End X
     - end_x
     - text
     - —
     - 
     - Optional upper x-bound for the multiplication operation; leave null to use the natural end of the curves.
   * - Limit Scaling To These Curves
     - indices
     - scalar
     - —
     - 
     - Optional zero-based index or index list selecting a subset of curve pairs to process; leave null to process all pairs.

Outputs
-------

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

   * - Label
     - ID
     - Type
     - Description
   * - curves_multiply_pairs_output_1
     - curves_multiply_pairs_output_1
     - vector
     - Resulting curve group containing one output curve per input pair, where each output y-value is the product of the interpolated y-values of the two input curves at each shared x-point.

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

- data.curve.pair
- 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=curves_multiply_pairs <https://www.d3view.com/api/workflow/example?id=curves_multiply_pairs>`_

.. raw:: html

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   Auto-generated from <code>transformation</code> schema. Worker id: <code>curves_multiply_pairs</code>. Schema hash: <code>27b2fc011b57</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
   </p>