FIT THE CUBIC SPLINE¶
Fits a cubic (or arbitrary-order) smoothing spline to an input curve using a specified number of knots and regions. Supports optional k-fold cross-validation to automatically select the best spline order and knot count, with a lambda penalty controlling knot contribution. Use this worker to smooth or resample noisy time-history or force-displacement curves.
When to use¶
Classification: process.
Tagged: cross_validation, cubic_spline, curve_smoothing, curve_transform, downsampling, k-fold, knots, lambda.
Inputs¶
| Label | ID | Type | Default | Required | Description |
|---|---|---|---|---|---|
| Curve In | curve_in | vector | — | Input curve (x/y vector) to be fitted with a smoothing spline; typically a time-history or force-displacement signal. | |
| Order | order | scalar | 3 | Polynomial order of the spline fit (default 3 = cubic); when cross-validation is enabled, this becomes the maximum order evaluated. | |
| Number Of Knots | numberof_knots | scalar | 1 | Number of interior knots placed in the spline (default 1); when cross-validation is enabled, this becomes the maximum number of knots evaluated. | |
| Number Of Regions | numberof_regions | scalar | 1 | Number of piecewise regions for the spline (default 1); only used when Validation is set to ‘None’. | |
| Validation | validation | scalar | none | Cross-validation strategy for automatic order/knot selection: ‘None’ uses the fixed parameters directly; ‘K-Fold 3/5/10’ performs k-fold CV to find the optimal configuration (default: None). | |
| Lambda | lambda | scalar | 1 | Regularisation penalty factor controlling the contribution of each knot (default 1.0); higher values produce smoother fits with fewer effective knots. |
Outputs¶
| Label | ID | Type | Description |
|---|---|---|---|
| Cubic Spline Curve | curve_cs_output_1 | vector | Fitted cubic spline curve (x/y vector) evaluated over the same domain as the input, representing the smoothed or resampled result. |
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_cubic_spline
Auto-generated from transformation schema. Worker id: curve_cubic_spline. Schema hash: 1bca1eb6bc0a. Hand-curated docs in workerexamples/ override this page when present.