.. _auto_curve_scale_by_curve:

*SCALE Y VALUES BY A CURVE*
===========================

Scales the Y values of a base curve by multiplying them point-wise with the Y values of a second "scale" curve, interpolated over the base curve's X domain. Use this worker when a spatially or temporally varying scale factor — itself expressed as a curve — needs to be applied to another curve's amplitude.

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

Classification: **process**.

Tagged: ``curve``, ``curve-by-curve``, ``point-wise``, ``scale``, ``transform``, ``y-scaling``.

Inputs
------

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

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - Base Curve
     - base_curve
     - vector
     - —
     - ✓
     - The input curve whose Y values will be scaled; supply as an (X, Y) vector pair — this is the curve whose amplitude is modified.
   * - Curve To Use For Scale
     - curvetousefor_scale
     - vector
     - —
     - ✓
     - The scale curve whose Y values act as the per-point multipliers applied to the base curve; interpolated onto the base curve's X axis before multiplication.
   * - after_x
     - after_x
     - string
     - 0
     - 
     - X-axis threshold below which no scaling is applied; scaling begins only for X values greater than this value. Defaults to 0 (scale from the start of the curve).
   * - Digitize Scale Curve
     - every
     - string
     - 10
     - 
     - Digitization step for the scale curve: the scale curve is re-sampled at this X interval before interpolation; set to 0 to use only the scale curve's critical (inflection/peak) points instead of a uniform step. Defaults to 10.

Outputs
-------

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

   * - Label
     - ID
     - Type
     - Description
   * - Scaled Curve
     - curve_scale_by_curve_output_1
     - vector
     - The resulting (X, Y) curve after the base curve's Y values have been multiplied by the interpolated Y values of the scale curve, starting from the specified after_x threshold.

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=curve_scale_by_curve <https://www.d3view.com/api/workflow/example?id=curve_scale_by_curve>`_

.. raw:: html

   <hr style="margin-top:2em">
   <p style="font-size:11px;color:#888">
   Auto-generated from <code>transformation</code> schema. Worker id: <code>curve_scale_by_curve</code>. Schema hash: <code>2a35691551d9</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
   </p>