你好,我是scikit学习的新手,我正在尝试做一些文本多类分类,我正在遵循this教程。
我的数据集有4个类'fipdl', 'lna','m5s','pd'
,所以我得到了4个文件夹(一个用于类),每个文件夹包含120个文本文件,大约25行文本(facebook状态)。
我把90%用于培训,10%用于测试。
10%的txt文件名以“ts”开头,我正在使用这些文件进行测试。
所以我的代码是:
import sys
import os
import time
from sklearn.feature_extraction.text import TfidfVectorizer
from sklearn import svm
from sklearn.metrics import classification_report
from sklearn.preprocessing import MultiLabelBinarizer
def usage():
print("Usage:")
print("python %s <data_dir>" % sys.argv[0])
if __name__ == '__main__':
if len(sys.argv) < 2:
usage()
sys.exit(1)
data_dir = sys.argv[1]
classes = ['fipdl', 'lna','m5s','pd']
# Read the data
train_data = []
train_labels = []
test_data = []
test_labels = []
for curr_class in classes:
dirname = os.path.join(data_dir, curr_class)
for fname in os.listdir(dirname):
with open(os.path.join(dirname, fname), 'r') as f:
content = f.read()
if fname.startswith('ts'):
test_data.append(content)
test_labels.append(curr_class)
else:
train_data.append(content)
train_labels.append(curr_class)
# Create feature vectors
vectorizer = TfidfVectorizer(min_df=5,
max_df = 0.8,
sublinear_tf=True,
use_idf=True)
train_vectors = vectorizer.fit_transform(train_data)
test_vectors = vectorizer.transform(test_data)
# Perform classification with SVM, kernel=rbf
classifier_rbf = svm.SVC()
t0 = time.time()
classifier_rbf.fit(train_vectors, train_labels)
t1 = time.time()
prediction_rbf = classifier_rbf.predict(test_vectors)
t2 = time.time()
time_rbf_train = t1-t0
time_rbf_predict = t2-t1
# Perform classification with SVM, kernel=linear
classifier_linear = svm.SVC(kernel='linear')
t0 = time.time()
classifier_linear.fit(train_vectors, train_labels)
t1 = time.time()
prediction_linear = classifier_linear.predict(test_vectors)
t2 = time.time()
time_linear_train = t1-t0
time_linear_predict = t2-t1
# Perform classification with SVM, kernel=linear
classifier_liblinear = svm.LinearSVC()
t0 = time.time()
classifier_liblinear.fit(train_vectors, train_labels)
t1 = time.time()
prediction_liblinear = classifier_liblinear.predict(test_vectors)
t2 = time.time()
time_liblinear_train = t1-t0
time_liblinear_predict = t2-t1
# Print results in a nice table
print("Results for SVC(kernel=rbf)")
print("Training time: %fs; Prediction time: %fs" % (time_rbf_train, time_rbf_predict))
print(classification_report(test_labels, prediction_rbf))
print("Results for SVC(kernel=linear)")
print("Training time: %fs; Prediction time: %fs" % (time_linear_train, time_linear_predict))
print(classification_report(test_labels, prediction_linear))
print("Results for LinearSVC()")
print("Training time: %fs; Prediction time: %fs" % (time_liblinear_train, time_liblinear_predict))
print(classification_report(test_labels, prediction_liblinear))
输出:
^{pr2}$现在结果似乎太好了,不可能是真的,因为每种方法都给了我1的精确度。
我想最好是尝试预测我传递的字符串而不是测试集,因为要做更多的测试,所以我将原始代码改为:
import sys
import os
import time
from sklearn.feature_extraction.text import TfidfVectorizer
from sklearn import svm
from sklearn.metrics import classification_report
from sklearn.preprocessing import MultiLabelBinarizer
def usage():
print("Usage:")
print("python %s <data_dir>" % sys.argv[0])
if __name__ == '__main__':
if len(sys.argv) < 2:
usage()
sys.exit(1)
data_dir = sys.argv[1]
classes = ['fipdl', 'lna','m5s','pd']
# Read the data
train_data = []
train_labels = []
test_data = []
test_labels = []
for curr_class in classes:
dirname = os.path.join(data_dir, curr_class)
for fname in os.listdir(dirname):
with open(os.path.join(dirname, fname), 'r') as f:
content = f.read()
if fname.startswith('ts'):
test_data.append(content)
test_labels.append(curr_class)
else:
train_data.append(content)
train_labels.append(curr_class)
# Create feature vectors
vectorizer = TfidfVectorizer(min_df=5,
max_df = 0.8,
sublinear_tf=True,
use_idf=True)
string = ['string to predict'] #my string
vector = vectorizer.transform(string) #convert
train_vectors = vectorizer.fit_transform(train_data)
test_vectors = vectorizer.transform(test_data)
# Perform classification with SVM, kernel=rbf
classifier_rbf = svm.SVC()
t0 = time.time()
classifier_rbf.fit(train_vectors, train_labels)
t1 = time.time()
prediction_rbf = classifier_rbf.predict(vector) #predict
t2 = time.time()
time_rbf_train = t1-t0
time_rbf_predict = t2-t1
# Perform classification with SVM, kernel=linear
classifier_linear = svm.SVC(kernel='linear')
t0 = time.time()
classifier_linear.fit(train_vectors, train_labels)
t1 = time.time()
prediction_linear = classifier_linear.predict(test_vectors)
t2 = time.time()
time_linear_train = t1-t0
time_linear_predict = t2-t1
# Perform classification with SVM, kernel=linear
classifier_liblinear = svm.LinearSVC()
t0 = time.time()
classifier_liblinear.fit(train_vectors, train_labels)
t1 = time.time()
prediction_liblinear = classifier_liblinear.predict(test_vectors)
t2 = time.time()
time_liblinear_train = t1-t0
time_liblinear_predict = t2-t1
# Print results in a nice table
print("Results for SVC(kernel=rbf)")
print("Training time: %fs; Prediction time: %fs" % (time_rbf_train, time_rbf_predict))
print(classification_report(test_labels, prediction_rbf))
print("Results for SVC(kernel=linear)")
print("Training time: %fs; Prediction time: %fs" % (time_linear_train, time_linear_predict))
print(classification_report(test_labels, prediction_linear))
print("Results for LinearSVC()")
print("Training time: %fs; Prediction time: %fs" % (time_liblinear_train, time_liblinear_predict))
print(classification_report(test_labels, prediction_liblinear))
但它失败了
ValueError: Found arrays with inconsistent numbers of samples: [18 44]
我遗漏了什么?或者这是一个完全错误的方法?
如有任何帮助,我们将不胜感激,
先谢谢尼科。在
您将创建向量器的新实例,并在拟合它之前,使用
^{pr2}$transform
方法。只需更改最后两行的顺序,如下所示:即使我还没有弄清楚为什么它能给我带来完美的结果,我还是决定用一种不同的方法对我的文本进行分类(使用多项式nb),并用我选择的字符串进行测试。我不确定这是否是最好的方法,但它是有效的,所以我决定张贴作为答案: (请注意,并非所有代码行都是必需的)
然后从控制台运行
script.py "string to predict"
可以对这段代码做很多改进,比如转储经过训练的模型,但对我的使用来说已经足够了。在
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