Python 无法在逻辑回归中使用决策函数()评估分数
我正在做华盛顿大学的这项作业,我必须使用LogisticRecession中的decision函数()预测样本测试矩阵(最后几行)的分数。但我得到的错误是Python 无法在逻辑回归中使用决策函数()评估分数,python,machine-learning,scikit-learn,logistic-regression,Python,Machine Learning,Scikit Learn,Logistic Regression,我正在做华盛顿大学的这项作业,我必须使用LogisticRecession中的decision函数()预测样本测试矩阵(最后几行)的分数。但我得到的错误是 ValueError: X has 145 features per sample; expecting 113092 代码如下: import pandas as pd import numpy as np from sklearn.linear_model import LogisticRegression
ValueError: X has 145 features per sample; expecting 113092
代码如下:
import pandas as pd
import numpy as np
from sklearn.linear_model import LogisticRegression
products = pd.read_csv('amazon_baby.csv')
def remove_punct (text) :
import string
text = str(text)
for i in string.punctuation:
text = text.replace(i,"")
return(text)
products['review_clean'] = products['review'].apply(remove_punct)
products = products[products.rating != 3]
products['sentiment'] = products['rating'].apply(lambda x : +1 if x > 3 else -1 )
train_data_index = pd.read_json('module-2-assignment-train-idx.json')
test_data_index = pd.read_json('module-2-assignment-test-idx.json')
train_data = products.loc[train_data_index[0], :]
test_data = products.loc[test_data_index[0], :]
train_data = train_data.dropna()
test_data = test_data.dropna()
from sklearn.feature_extraction.text import CountVectorizer
train_matrix = vectorizer.fit_transform(train_data['review_clean'])
test_matrix = vectorizer.fit_transform(test_data['review_clean'])
sentiment_model = LogisticRegression()
sentiment_model.fit(train_matrix, train_data['sentiment'])
print (sentiment_model.coef_)
sample_data = test_data[10:13]
print (sample_data)
sample_test_matrix = vectorizer.transform(sample_data['review_clean'])
scores = sentiment_model.decision_function(sample_test_matrix)
print (scores)
以下是产品数据:
Name Review Rating
0 Planetwise Flannel Wipes These flannel wipes are OK, but in my opinion ... 3
1 Planetwise Wipe Pouch it came early and was not disappointed. i love... 5
2 Annas Dream Full Quilt with 2 Shams Very soft and comfortable and warmer than it l... 5
3 Stop Pacifier Sucking without tears with Thumb... This is a product well worth the purchase. I ... 5
4 Stop Pacifier Sucking without tears with Thumb... All of my kids have cried non-stop when I trie... 5
此行导致后续行中出现错误:
test_matrix = vectorizer.fit_transform(test_data['review_clean'])
将上述内容更改为:
test_matrix = vectorizer.transform(test_data['review_clean'])
说明:使用fit_transform()将在测试数据上重新安装CountVector。因此,有关训练数据的所有信息都将丢失,词汇将仅从测试数据中计算
然后使用矢量器
对象转换样本数据['review\u clean']
。因此,其中的功能将仅是从测试数据中学习的功能
但是情绪模型
是根据训练数据
中的词汇进行训练的。因此,特征是不同的
始终在测试数据上使用transform()
,永远不要使用fit\u transform()
太好了,它起作用了。谢谢你能告诉我为什么会这样吗?@harshi我补充了解释。请仔细检查,如果仍然不理解,请询问。同样,如果这能帮助你考虑投票/接受答案。当然。谢谢