机器学习基础（九）之特征脸的绘制与下载

Jupyter Notebook
特征脸

import numpy as np
from matplotlib import pyplot as plt

fetch_lfw_people
from sklearn.datasets import fetch_lfw_people

faces = fetch_lfw_people()

print(faces.keys())
dict_keys(['data', 'images', 'target', 'target_names', 'DESCR'])

faces.data.shape
(13233, 2914)

faces.images.shape
(13233, 62, 47)

random_indexes = np.random.permutation(len(faces.data))

X = faces.data[random_indexes]

example_faces = X[:36,:]

example_faces.shape
(36, 2914)

#绘制脸的函数
def plot_faces(faces):
    
    fig, axes = plt.subplots(6, 6, figsize=(10, 10),
                           subplot_kw={'xticks':[], 'yticks':[]},
    gridspec_kw=dict(hspace=0.1, wspace=0.1))
    for i, ax in enumerate(axes.flat):
        ax.imshow(faces[i].reshape(62,47), cmap='bone')

plot_faces(example_faces)

​
注：如果用

from sklearn.datasets import fetch_lfw_people
faces = fetch_lfw_people()

出错，则参考：https://blog.csdn.net/pyufftj/article/details/79756327