UndefinedMetricWarning:Recall 和 F-score 定义错误,在没有真实样本的标签中设置为 0.0。 'recall'、'true'、平均值、warn_for)
UndefinedMetricWarning: Recall and F-score are ill-defined and being set to 0.0 in labels with no true samples. 'recall', 'true', average, warn_for)
当我使用下面的代码计算 precision_recall_fscore_support
一个 class(只有 1
s)
import numpy as np
from sklearn.metrics import precision_recall_fscore_support
#make arrays
ytrue = np.array(['1', '1', '1', '1', '1','1','1','1'])
ypred = np.array(['0', '0', '0', '1', '1','1','1','1'])
#keep only 1
y_true, y_pred = zip(*[[ytrue[i], ypred[i]] for i in range(len(ytrue)) if ytrue[i]=="1"])
#get scores
precision_recall_fscore_support(y_true, y_pred, average='weighted')
我收到以下警告:
UndefinedMetricWarning: Recall and F-score are ill-defined and being set to 0.0 in labels with no true samples.
'recall', 'true', average, warn_for)
并输出:
(1.0, 0.625, 0.76923076923076927, None)
我在 SO 上发现了以下具有类似警告的内容,但我认为它不适用于我的问题。
问题:我的输出结果是否有效,或者我应该关注警告消息吗?如果是这样,我的代码有什么问题以及如何解决?
你好,我找到了这个问题的解决方案,你需要使用:
cv = ShuffleSplit(n_splits=10, test_size=0.3, random_state=0)
我正在使用 knn,这解决了问题
代码:
def knn(self,X_train,X_test,Y_train,Y_test):
#implementación del algoritmo
knn = KNeighborsClassifier(n_neighbors=3).fit(X_train,Y_train)
#10XV
cv = ShuffleSplit(n_splits=10, test_size=0.3, random_state=0)
puntajes = sum(cross_val_score(knn, X_test, Y_test,
cv=cv,scoring='f1_weighted'))/10
print(puntajes)
**Link:**
https://scikit-learn.org/stable/modules/cross_validation.html
当我使用下面的代码计算 precision_recall_fscore_support
一个 class(只有 1
s)
import numpy as np
from sklearn.metrics import precision_recall_fscore_support
#make arrays
ytrue = np.array(['1', '1', '1', '1', '1','1','1','1'])
ypred = np.array(['0', '0', '0', '1', '1','1','1','1'])
#keep only 1
y_true, y_pred = zip(*[[ytrue[i], ypred[i]] for i in range(len(ytrue)) if ytrue[i]=="1"])
#get scores
precision_recall_fscore_support(y_true, y_pred, average='weighted')
我收到以下警告:
UndefinedMetricWarning: Recall and F-score are ill-defined and being set to 0.0 in labels with no true samples.
'recall', 'true', average, warn_for)
并输出:
(1.0, 0.625, 0.76923076923076927, None)
我在 SO
问题:我的输出结果是否有效,或者我应该关注警告消息吗?如果是这样,我的代码有什么问题以及如何解决?
你好,我找到了这个问题的解决方案,你需要使用:
cv = ShuffleSplit(n_splits=10, test_size=0.3, random_state=0)
我正在使用 knn,这解决了问题
代码:
def knn(self,X_train,X_test,Y_train,Y_test):
#implementación del algoritmo
knn = KNeighborsClassifier(n_neighbors=3).fit(X_train,Y_train)
#10XV
cv = ShuffleSplit(n_splits=10, test_size=0.3, random_state=0)
puntajes = sum(cross_val_score(knn, X_test, Y_test,
cv=cv,scoring='f1_weighted'))/10
print(puntajes)
**Link:** https://scikit-learn.org/stable/modules/cross_validation.html