sklearn的precision_score函数输入错误

Question

我正在尝试在python中从sklearn.metrics运行precision_score。 我的真实y和预测y均为稀疏矩阵格式-

import scipy.sparse as sp
from sklearn.metrics import accuracy_score
y_true = sp.csr_matrix(y.values) # where y is a multi-label dataframe
y_pred = model.predict(X) # X is same format as y_true    
accuracy_score(y_true, y_pred)

我收到以下错误：

TypeError: len() of unsized object

我检查了文档 ，它应该能够接受稀疏矩阵。

为了清楚起见，当我尝试查看其内容时，会同时获得以下内容：

[In]  y_true
[Out] <9646x1248 sparse matrix of type '<class 'numpy.int64'>'
                 with 36700 stored elements in Compressed Sparse Row format>
[In]  y_pred
[Out] <9646x1248 sparse matrix of type '<class 'numpy.int64'>'
                 with 373603 stored elements in Compressed Sparse Row format>

为什么会出现此错误，以及如何解决输入问题？

Answer 1

将矩阵转换为规则矩阵y_pred = y_pred.A和y_true = y_true.A ，然后计算accuracy_score(y_true, y_pred)