The clusteror.utils
Module¶
This module works as a transient store of useful functions. New standalone functions will be first placed here. As they grow in number and can be consolidated into an independent class, module, or even a new package.
-
clusteror.utils.
find_local_extremes
(series, contrast)[source]¶ Finds local minima and maxima according to
contrast
. In theory, they can be determined by first derivative and second derivative. The result derived this way is of no value in dealing with a very noisy, zig-zag data as too many local extremes would be found for any turn-around. The method presented here compares the point currently looked at and the opposite potential extreme that is updated as scanning through the data sequence. For instance, a potential maximum is 10, then a data point of value smaller than 10 / (1 + contrast) is written down as a local minimum.Parameters: - series (Pandas Series) – One dimenional data to find local extremes in.
- contrast (float) – A value between 0 and 1 as a threshold between minimum and maximum.
Returns: - local_min_inds (list) – List of indices for local minima.
- local_mins (list) – List of minimum values.
- local_max_inds (list) – List of indices for local maxima.
- local_maxs (list) – List of maximum values.