机器学习基石第二讲 Learning to Answer Yes/No

 1 import cv2
 2 import os
 3 import numpy
 4 import glob
 5 
 6 class Percetron(object):
 7     def __init__(self, image_x_dimension, image_y_dimension, positive_dimension, negtive_dimension):
 8         self.image_x_dimension = image_x_dimension
 9         self.image_y_dimension = image_y_dimension
10         self.positive_dimension = positive_dimension
11         self.negtive_dimension = negtive_dimension
12         self.dimension = self.image_x_dimension * self.image_y_dimension + 1
13         self.count = self.positive_dimension + self.negtive_dimension
14 
15     def image2vector(self, filename):
16         returnVect = numpy.zeros((1,self.dimension))
17         file_matrix = cv2.imread(filename, cv2.IMREAD_GRAYSCALE)
18         returnVect[0, 0] = 1
19         for i in range(self.image_x_dimension):
20             for j in range(self.image_y_dimension):
21                 returnVect[0, self.image_y_dimension * i + j + 1] = float(file_matrix[i, j])
22         return returnVect
23 
24     def image2Matrix(self):
25         X_train = numpy.zeros((self.count, self.dimension))
26         i = 0
27         for bmp in glob.glob(".\*.bmp"):
28             X_train[i, :] = self.image2vector(bmp)
29             i += 1
30         return X_train
31 
32     def yMatrix(self):
33         y_train = numpy.zeros((self.count, 1))
34         for i in range(self.negtive_dimension):
35             y_train[i] = -1
36         for i in range(self.positive_dimension):
37             y_train[i + self.negtive_dimension] = 1
38         return y_train
39 
40     def opPercetron(self):
41         w = numpy.zeros((self.dimension, 1))
42         X_train = self.image2Matrix()
43         y_train = self.yMatrix()
44         while True:
45             flag = 0
46             num = 0
47             for i in range(self.count):
48                 if  numpy.dot(X_train[i, :], w)[0] * y_train[i] <= 0:
49                     w += y_train[i, 0] * X_train[i,:].reshape(self.dimension, 1)
50                     flag = 1
51             if flag == 0:
52                 break
53         return w
54 
55     def accuracy(self, w):
56         num = 0
57         X_test = self.image2Matrix()
58         y_test = self.yMatrix()
59         for i in range(self.count):
60             if numpy.dot(X_test[i, :], w)[0] * y_test[i] > 0:
61                 num += 1
62         print float(num) / self.count
63 
64 
65 my_train_Percetron = Percetron(28, 28, 800, 800)
66 os.chdir("C:\Users\samsung\Desktop\Perceptron_train")
67 w = my_train_Percetron.opPercetron()
68 my_train_Percetron.accuracy(w)
69 
70 my_test_Percetron = Percetron(28, 28, 180, 335)
71 os.chdir("C:\Users\samsung\Desktop\Perceptron_test")
72 my_test_Percetron.accuracy(w)