targets[positive_indices, :] = 0
时间: 2024-01-17 14:05:42 浏览: 30
This line of code sets all the elements in the rows specified by the indices in the positive_indices array to 0.
Assuming that targets is a 2-dimensional numpy array, this line of code uses numpy's indexing syntax to select a subset of rows and all columns in the array. The selected rows are those specified by the positive_indices array, which presumably contains a list of indices corresponding to positive training examples.
By setting all elements in these rows to 0, this line effectively removes the positive examples from the training data. This could be useful in situations where the dataset is imbalanced and the model is overfitting to the positive examples. Removing some of the positive examples can help to balance the dataset and prevent overfitting.
It's important to note that this line modifies the original targets array in place. If you want to keep a copy of the original array, you should make a copy before modifying it.