Extrema Finder Utility

Identify extrema points in one-dimensional numerical series.

This module provides helper functions for identifying extrema in one-dimensional data series commonly produced by ReaxFF simulations, such as energy profiles, bond-order trajectories, dipole signals, polarization loops, or field-response curves.

Usage context

• Energy profiling: Locate global or local minima and maxima in trajectories.
• Field-response analysis: Identify peak responses in driven simulations.
• Transition detection: Capture switching points in time-series signals.

Function: get_extrema_points

Identify extrema points in a 1D data series.

This function extracts global or local extrema by locating maximum and/or minimum values of a y-series with respect to a corresponding x-series. Optionally, the x-axis may be partitioned into windows to detect local extrema within each segment.

Parameters:

Name	Type	Description	Default
y_series	Series or array - like	Dependent variable values (e.g., energy, polarization, bond order).	required
x_series	Series or array - like	Independent variable values (e.g., iteration index or time).	required
mode	(max, min, minmax)	Type of extrema to extract: - 'max': maxima only - 'min': minima only - 'minmax': both minima and maxima	'max'
chunk_size	float or int	Size of the x-axis window used to find local extrema. If not provided, only global extrema are returned.	None

Returns:

Type	Description
list of tuple[float, float]	List of (x, y) pairs corresponding to detected extrema points.

Examples:

>>> get_extrema_points(energy, iters, mode="min")
>>> get_extrema_points(signal, time, mode="minmax", chunk_size=50)