我不是专家用户。我知道我可以获得混淆矩阵,但是我想获得一个以错误方式分类的行的列表,以便在分类后对其进行研究。
在 stackoverflow 上,我发现这个Can I get a list of wrong predictions in SVM score function in scikit-learn但我不确定是否理解了所有内容。
这是一个示例代码。
# importing necessary libraries
from sklearn import datasets
from sklearn.metrics import confusion_matrix
from sklearn.model_selection import train_test_split
# loading the iris dataset
iris = datasets.load_iris()
# X -> features, y -> label
X = iris.data
y = iris.target
# dividing X, y into train and test data
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state = 0)
# training a linear SVM classifier
from sklearn.svm import SVC
svm_model_linear = SVC(kernel = 'linear', C = 1).fit(X_train, y_train)
svm_predictions = svm_model_linear.predict(X_test)
# model accuracy for X_test
accuracy = svm_model_linear.score(X_test, y_test)
# creating a confusion matrix
cm = confusion_matrix(y_test, svm_predictions)
要遍历行并找到错误的行,建议的解决方案是:
predictions = clf.predict(inputs)
for input, prediction, label in zip(inputs, predictions, labels):
if prediction != label:
print(input, 'has been classified as ', prediction, 'and should be ', label)
我不明白什么是“输入”/“输入”。如果我将此代码改编为我的代码,如下所示:
for input, prediction, label in zip (X_test, svm_predictions, y_test):
if prediction != label:
print(input, 'has been classified as ', prediction, 'and should be ', label)
我得到:
[6. 2.7 5.1 1.6] has been classified as 2 and should be 1
第 6 行是错误的行吗?6.后面的数字是多少?我问这个是因为我在比这个更大的数据集上使用相同的代码,所以我想确保我做的是正确的事情。我没有发布其他数据集,因为不幸的是我不能,但问题是我得到了这样的东西:
(0, 253) 0.5339655767137572
(0, 601) 0.27665553856928027
(0, 1107) 0.7989633757962163 has been classified as 7 and should be 3
(0, 885) 0.3034934766501018
(0, 1295) 0.6432561790864061
(0, 1871) 0.7029318585026516 has been classified as 7 and should be 6
(0, 1020) 1.0 has been classified as 3 and should be 8
当我计算最后一个输出的每一行时,我得到了测试集的两倍......所以我不确定我正在分析的预测结果列表是否完全错误......我希望已经足够清楚了。