plot_sequential_feature_selection: 可视化来自SequentialFeatureSelector的选定特征子集性能

一个用于可视化feature_selection.SequentialFeatureSelector结果的matplotlib工具函数。

来自 mlxtend.plotting 的 plot_sequential_feature_selection

概述

有关顺序特征选择的更多信息，请参见 feature_selection.SequentialFeatureSelector。

示例 1 - 绘制来自顺序特征选择器的结果

from mlxtend.plotting import plot_sequential_feature_selection as plot_sfs
from mlxtend.feature_selection import SequentialFeatureSelector as SFS
import matplotlib.pyplot as plt
from sklearn.neighbors import KNeighborsClassifier
from sklearn.datasets import load_iris

iris = load_iris()
X = iris.data
y = iris.target
knn = KNeighborsClassifier(n_neighbors=4)

sfs = SFS(knn, 
          k_features=4, 
          forward=True, 
          floating=False,
          scoring='accuracy',
          cv=5)

sfs = sfs.fit(X, y)

fig1 = plot_sfs(sfs.get_metric_dict(),
                kind='std_dev',
                figsize=(6, 4))

plt.ylim([0.8, 1])
plt.title('Sequential Forward Selection (w. StdDev)')
plt.grid()
plt.show()

API

plot_sequential_feature_selection(metric_dict, figsize=None, kind='std_dev', color='blue', bcolor='steelblue', marker='o', alpha=0.2, ylabel='Performance', confidence_interval=0.95)

Plot feature selection results.

Parameters

• metric_dict : mlxtend.SequentialFeatureSelector.get_metric_dict() object

• figsize : tuple (default: None)

  Height and width of the figure

• kind : str (default: "std_dev")

  The kind of error bar or confidence interval in {'std_dev', 'std_err', 'ci', None}.

• color : str (default: "blue")

  Color of the lineplot (accepts any matplotlib color name)

• bcolor : str (default: "steelblue").

  Color of the error bars / confidence intervals (accepts any matplotlib color name).

• marker : str (default: "o")

  Marker of the line plot (accepts any matplotlib marker name).

• alpha : float in [0, 1] (default: 0.2)

  Transparency of the error bars / confidence intervals.

• ylabel : str (default: "Performance")

  Y-axis label.

• confidence_interval : float (default: 0.95)

  Confidence level if kind='ci'.

Returns

• fig : matplotlib.pyplot.figure() object

Examples

For usage examples, please see https://rasbt.github.io/mlxtend/user_guide/plotting/plot_sequential_feature_selection/

ython