AREA BETWEEN A CURVE AND A BASELINE¶
Computes the trapezoidal area between a curve and a baseline over an X range. The baseline can be the straight chord between the X limits (DSC peak energy / hysteresis loop convention), the X axis, or a horizontal line at a chosen Y value. Crossing handled by zero-split when area mode is ‘absolute’, so the result matches a fine-grained hand calculation.
When to use¶
Classification: process.
Tagged: ASTM_E2070, DSC, area_above_baseline, baseline_subtraction, chord, curve_integral, enclosed_area, hysteresis.
Inputs¶
| Label | ID | Type | Default | Required | Description |
|---|---|---|---|---|---|
| Curve | curve | vector | — | Input XY curve. The area returned is the integral of (Curve minus baseline) between the X limits. | |
| X Left | x_left | string | — | Left X integration limit. Leave blank to use the curve’s left endpoint. | |
| X Right | x_right | string | — | Right X integration limit. Leave blank to use the curve’s right endpoint. | |
| Baseline Mode | baseline_mode | select | endpoints | ‘Endpoints’ draws a straight baseline from (X Left, y(X Left)) to (X Right, y(X Right)) and integrates the curve minus that line; this is the DSC / ASTM E2070 convention for peak energy and applies to hysteresis loops, transition energies, and any ‘area above a chord’ calculation. ‘Y=0’ integrates against the X axis (curve minus zero) over the X range. ‘Horizontal’ integrates against the constant Y value set in ‘Y Baseline’. | |
| Y Baseline | y_baseline | string | 0 | Constant Y value used as the baseline when Baseline Mode is ‘Horizontal’. Ignored otherwise. | |
| Area Mode | area_mode | select | signed | ‘Signed’ returns the net trapezoidal integral of (curve - baseline); regions where the curve dips below the baseline subtract from the total. ‘Absolute’ returns the integral of the absolute difference; sign changes within a segment are handled by splitting that segment at the zero crossing so the answer matches a fine-grained hand calculation. |
Outputs¶
| Label | ID | Type | Description |
|---|---|---|---|
| curve_area_above_baseline_output_1 | curve_area_above_baseline_output_1 | scalar | Scalar area in natural units of X x Y. With Baseline Mode = ‘Endpoints’ this is the ASTM E2070 peak energy or hysteresis area between the chord and the curve; with ‘Y=0’ it is the ordinary integral of the curve; with ‘Horizontal’ it is the integral above a constant Y line. |
Disciplines¶
- data.curve.transform
- data.statistics
- engineering.material.characterization
- engineering.thermal_analysis
Runnable example¶
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