FindPeaksCWT — Peak finding with continuous wavelet transforms.¶

This module defines a wrapper class for the scipy.signal.find_peaks_cwt method.

class admit.util.peakfinder.FindPeaksCWT.FindPeaksCWT(spec, x=None, **kwargs)[source]¶

Parameters:

spec : List or numpy array

The spectrum to be analyzed.

x : List or numpy array, optional

The x co-ordinates for the spectrum. Default = None.

kwarg : Dict

Any additional arguments, see the Attributes list for a complete listing.

Attributes

spec	(numpy array) The spectrum to be analyzed.
x	(numpy array) The x co-ordinates of the spectrum.
widths	(sequence) 1-D array of widths to use for calculating the CWT matrix. In general, this range should cover the expected width of peaks of interest.
wavelet	(callable, optional) Should take a single variable and return a 1-D array to convolve with vector. Should be normalized to unit area. Default: None (ricker wavelet).
max_distances	(ndarray, optional) At each row, a ridge line is only connected if the relative max at row[n] is within max_distances[n] from the relative max at row[n+1]. Default: widths/4.
gap_thresh	(float, optional) If a relative maximum is not found within max_distances, there will be a gap. A ridge line is discontinued if there are more than gap_thresh points without connecting a new relative maximum. Default: 5.
min_length	(int, optional) Minimum length a ridge line needs to be acceptable. Default: cwt.shape[0] / 4, ie 1/4-th the number of widths.
min_snr	(float, optional) Minimum SNR ratio. Default 1. The signal is the value of the cwt matrix at the shortest length scale (cwt[0, loc]), the noise is the noise_perc-th percentile of datapoints contained within a window of window_size around cwt[0, loc]. Default: 3.
noise_perc	(float, optional) When calculating the noise floor, percentile of data points examined below which to consider noise. Calculated using stats.scoreatpercentile. Default: 10.

Methods

find() Method to find any peaks in the spectrum.

Method to find any peaks in the spectrum. A baseline will be subtracted first if requested.

Parameters:

None

Returns:

numpy array of floats

containing the locations of the peaks