DETECT SIGN CHANGES BASED ON 3RD DERIVATIVE SIGN CHANGE¶
Computes the n-th order derivative of a curve and detects sign changes where the derivative magnitude exceeds a threshold ratio, flagging inflection-like events. Use this worker to identify significant curvature transitions or instability points in time-history or load-displacement data.
When to use¶
Classification: process.
Tagged: 3rd_derivative, curve_analysis, derivative, inflection, sign_change, threshold.
Inputs¶
| Label | ID | Type | Default | Required | Description |
|---|---|---|---|---|---|
| Curve | curve | vector | — | Input X-Y curve (e.g. time-history or load-displacement) on which the derivative analysis is performed; provide as a two-column vector [x, y]. | |
| Order | order | scalar | 3 | Derivative order to compute before checking the sign-change threshold; defaults to 3 (third derivative), leave at default for standard inflection detection. | |
| Ratio | ratio | scalar | 0.75 | Fractional threshold (0–1) relative to the derivative’s peak magnitude; a sign change is only flagged when the local derivative exceeds this ratio — defaults to 0.75, increase to suppress minor fluctuations. |
Outputs¶
| Label | ID | Type | Description |
|---|---|---|---|
| curve_derivative_exceeds_threshold_output_1 | curve_derivative_exceeds_threshold_output_1 | string | String result reporting the detected sign-change locations or status flags where the n-th order derivative exceeded the specified ratio threshold. |
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_derivative_exceeds_threshold
Auto-generated from transformation schema. Worker id: curve_derivative_exceeds_threshold. Schema hash: 0c586adf129a. Hand-curated docs in workerexamples/ override this page when present.