scipy.signal.

argrelextrema#

scipy.signal.argrelextrema(data, comparator, axis=0, order=1, mode='clip')[source]#

Calculate the relative extrema of data.

Parameters:

datandarray: Array in which to find the relative extrema.
comparatorcallable: Function to use to compare two data points. Should take two arrays as arguments.
axisint, optional: Axis over which to select from data. Default is 0.
orderint, optional: How many points on each side to use for the comparison to consider comparator(n, n+x) to be True.
modestr, optional: How the edges of the vector are treated. ‘wrap’ (wrap around) or ‘clip’ (treat overflow as the same as the last (or first) element). Default is ‘clip’. See numpy.take.

Returns:

extrematuple of ndarrays: Indices of the maxima in arrays of integers. extrema[k] is the array of indices of axis k of data. Note that the return value is a tuple even when data is 1-D.

See also

argrelmin, argrelmax

Notes

Added in version 0.11.0.

Examples

>>> import numpy as np
>>> from scipy.signal import argrelextrema
>>> x = np.array([2, 1, 2, 3, 2, 0, 1, 0])
>>> argrelextrema(x, np.greater)
(array([3, 6]),)
>>> y = np.array([[1, 2, 1, 2],
...               [2, 2, 0, 0],
...               [5, 3, 4, 4]])
...
>>> argrelextrema(y, np.less, axis=1)
(array([0, 2]), array([2, 1]))