Functions

Functions

The package exposes a small set of user-facing functions. The main entry point is path_features(), which returns the notation used in the paper.

path_features(path, depth = 4)

Computes the low-order path coordinates for a two-column path cbind(u, F). The returned columns are p2, p_pm, p3u, p3F, p4F, and p4T.

classical_features(path)

Returns classical line-profile summaries for comparison: total line flux, equivalent width, peak flux, FWHM, W80, centroid, line dispersion, skewness, and excess kurtosis.

as_spectral_path(u, F)

Builds the two-column matrix expected by the feature functions, with the ordered coordinate in the first column and the measured signal in the second.

Paper notation

p2

Signed area in the ordered-coordinate–flux plane.

p3u

Third-order coordinate sensitive to where profile imbalance occurs along the ordered coordinate.

p3F

Third-order coordinate sensitive to whether structure is associated with brighter or fainter parts of the line.

p4F

Fourth-order flux modulation.

p4T

Fourth-order mixed coordinate used for bends, shoulders, and multi-component profile structure.

p_pm

Signed ordering of emission and absorption in mixed-sign profiles.