84 lines
2.7 KiB
Python
84 lines
2.7 KiB
Python
# Sebastian Raschka 2014-2020
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# mlxtend Machine Learning Library Extensions
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#
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# A function for plotting decision regions of classifiers.
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# Author: Sebastian Raschka <sebastianraschka.com>
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#
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# License: BSD 3 clause
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import matplotlib.pyplot as plt
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import numpy as np
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def ecdf(x, y_label='ECDF', x_label=None, ax=None, percentile=None,
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ecdf_color=None, ecdf_marker='o', percentile_color='black',
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percentile_linestyle='--'):
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"""Plots an Empirical Cumulative Distribution Function
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Parameters
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----------
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x : array or list, shape=[n_samples,]
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Array-like object containing the feature values
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y_label : str (default='ECDF')
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Text label for the y-axis
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x_label : str (default=None)
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Text label for the x-axis
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ax : matplotlib.axes.Axes (default: None)
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An existing matplotlib Axes. Creates
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one if ax=None
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percentile : float (default=None)
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Float between 0 and 1 for plotting a percentile
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threshold line
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ecdf_color : matplotlib color (default=None)
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Color for the ECDF plot; uses matplotlib defaults
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if None
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ecdf_marker : matplotlib marker (default='o')
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Marker style for the ECDF plot
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percentile_color : matplotlib color (default='black')
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Color for the percentile threshold if percentile is not None
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percentile_linestyle : matplotlib linestyle (default='--')
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Line style for the percentile threshold if percentile is not None
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Returns
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---------
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ax : matplotlib.axes.Axes object
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percentile_threshold : float
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Feature threshold at the percentile or None if `percentile=None`
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percentile_count : Number of if percentile is not None
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Number of samples that have a feature less or equal than
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the feature threshold at a percentile threshold
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or None if `percentile=None`
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Examples
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-----------
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For usage examples, please see
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http://rasbt.github.io/mlxtend/user_guide/plotting/ecdf/
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"""
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if ax is None:
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ax = plt.gca()
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x = np.sort(x)
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y = np.arange(1, x.shape[0] + 1) / float(x.shape[0])
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ax.plot(x, y,
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marker=ecdf_marker,
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linestyle='',
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color=ecdf_color)
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ax.set_ylabel('ECDF')
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if x_label is not None:
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ax.set_xlabel(x_label)
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if percentile:
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targets = x[y <= percentile]
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percentile_threshold = targets.max()
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percentile_count = targets.shape[0]
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ax.axvline(percentile_threshold,
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color=percentile_color,
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linestyle=percentile_linestyle)
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else:
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percentile_threshold = None
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percentile_count = None
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return ax, percentile_threshold, percentile_count
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