The dataset used in this example is a preprocessed excerpt of the "Labeled Faces in the Wild", aka LFW_:
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%matplotlib inline
from time import time
import logging
import matplotlib.pyplot as plt
import numpy as np
from sklearn.model_selection import train_test_split
from sklearn.model_selection import GridSearchCV
from sklearn.datasets import fetch_lfw_people
from sklearn.metrics import classification_report
from sklearn.metrics import confusion_matrix
from sklearn.decomposition import PCA
from sklearn.svm import SVC
from sklearn import manifold
from sklearn.decomposition import FastICA
print(__doc__)
# Display progress logs on stdout
logging.basicConfig(level=logging.INFO, format='%(asctime)s %(message)s')
lfw_people = fetch_lfw_people(min_faces_per_person=70, resize=0.4)
# introspect the images arrays to find the shapes (for plotting)
n_samples, h, w = lfw_people.images.shape
# for machine learning we use the 2 data directly (as relative pixel
# positions info is ignored by this model)
X = lfw_people.data
n_features = X.shape[1]
# the label to predict is the id of the person
y = lfw_people.target
target_names = lfw_people.target_names
n_classes = target_names.shape[0]
print("Total dataset size:")
print("n_samples: %d" % n_samples)
print("n_features: %d" % n_features)
print("n_classes: %d" % n_classes)
# split into a training and testing set
X_train, X_test, y_train, y_test = train_test_split(
X, y, test_size=0.25, random_state=42)
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n_components_1 = np.arange(150,240,3)
accuracies = []
components = []
# for i in xrange(len(n_components_1)):
n_components = 198
ica = FastICA(n_components=n_components)
S_ = ica.fit_transform(X)
A_ = ica.mixing_
X_train_ica = ica.transform(X_train)
X_test_ica = ica.transform(X_test)
param_grid = {'C': [1e3, 5e3, 1e4, 5e4, 1e5],
'gamma': [0.0001, 0.0005, 0.001, 0.005, 0.01, 0.1], }
clf = GridSearchCV(SVC(kernel='rbf', class_weight='balanced'), param_grid)
clf = clf.fit(X_train_ica, y_train)
y_pred = clf.predict(X_test_ica)
accuracies.append(float(np.sum(y_test==y_pred))/len(y_pred))
components.append(n_components)
print('For '+str(n_components)+' components, accuracy is '+str(float(np.sum(y_test==y_pred))/len(y_pred))+' confusion matrix is: ')
print(confusion_matrix(y_test, y_pred, labels=range(n_classes)))
print(classification_report(y_test, y_pred, target_names=target_names))
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icafaces = ica.components_.reshape((n_components, h, w))
def plot_gallery(images, titles, h, w, n_row=3, n_col=4):
"""Helper function to plot a gallery of portraits"""
# plt.figure(figsize=(1.8 * n_col, 2.4 * n_row))
plt.subplots_adjust(bottom=0, left=.01, right=.99, top=.90, hspace=.35)
for i in range(n_row * n_col):
plt.subplot(n_row, n_col, i + 1)
plt.imshow(images[i].reshape((h, w)), cmap=plt.cm.gray)
plt.title(titles[i], size=12)
plt.xticks(())
plt.yticks(())
icafaces_titles = ["ica comp %d" % i for i in range(icafaces.shape[0])]
plot_gallery(icafaces, icafaces_titles, h, w)
plt.show()
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