如何以Python代码实例展示kNN算法的实际运用

Python021

如何以Python代码实例展示kNN算法的实际运用,第1张

给样本数据集T={2,4,10,12,3,20,22,21,11,24} t={18},K=4 1. N={2,4,10,12},d1=16,d2=14,d3=8,d4=6 2.d={3},比较,N={4,10,12,3},d1=14,d2=8,d3=6,d4=15 3.d={20},比较,N={4,10,12,20},d1=14,d2=8,d3=6,d4=2 4.d={22},比较,N={10,12,20,22},

参考了其他博主的代码 想试着运行 然后去理解。结果一直报错，希望大神帮帮忙。

import numpy as np

import os

import kNN

def img2vector(filename):

"""函数将以文本格式出现的32*32的0-1图片，转变成一维特征数组，返回一维数组

Keyword argument:

filename -- 文本格式的图片文件

"""

imgvect = np.zeros((1, 1024))

fr = open(filename)

for i in range(32):

linestr = fr.readline()

for j in range(32):

imgvect[0, 32*i + j] = int(linestr[j])

return imgvect

def handwriteClassfiy(testfile, trainfile, k):

"""函数将trainfile中的文本图片转换成样本特征集和样本类型集，用testfile中的测试样本测试，无返回值

Keyword argument:

testfile -- 测试图片目录

trainfile -- 样本图片目录

"""

trainFileList = os.listdir(trainfile)

trainFileSize = len(trainFileList)

labels = []

trainDataSet = np.zeros((trainFileSize, 1024))

for i in range(trainFileSize):

filenameStr = trainFileList[i]

digitnameStr = filenameStr.split('.')[0]

digitLabels = digitnameStr.split('_')[0]

labels.append(digitLabels)

trainDataSet[i, :] = img2vector(trainfile + '/' + filenameStr)

testFileList = os.listdir(testfile)

testNumber = len(testFileList)

errorcount = 0.0

for testname in testFileList:

testdigit = img2vector(testfile + '/' + testname)

classifyresult = kNN.classfiy(testdigit, trainDataSet, labels, k)

testStr = testname.split('.')[0]

testDigitLabel = testStr.split('_')[0]

if classifyresult != testDigitLabel:

errorcount += 1.0

#print('this test real digit is：%s, and the result is: %s' % (testDigitLabel, classifyresult))

print('k = %d, errorRatio is: %f' % (k, errorcount/float(testNumber)))

return

if __name__ == '__main__':

filename = 'C:/Users/lx/Desktop/MachineLearning-master/kNN/use Python and NumPy/testDigits/0_1.txt'

traindir= 'C:/Users/lx/Desktop/MachineLearning-master/kNN/use Python and NumPy/trainingDigits'

testdir = 'C:/Users/lx/Desktop/MachineLearning-master/kNN/use Python and NumPy/testDigits'

handwriteClassfiy(testdir, traindir, 3)

错误提示Traceback (most recent call last):

File "kNN.py", line 56, in <module>

handwriteClassfiy(testdir, traindir, 3)

File "kNN.py", line 43, in handwriteClassfiy

classifyresult = kNN.classfiy(testdigit, trainDataSet, labels, k)

AttributeError: module 'kNN' has no attribute 'classfiy'

你这个文件是不是就叫 kNN.py ？如果是的话那你这个里面根本就没有 classfiy 这个属性，当然会报错。

另外，import kNN 是 import 自己？