How to calculate the confusion matrix?

[Agito555]

I noticed that in your article, there is an illustration related to the confusion matrix. However, I couldn't find a corresponding API call in mmdetection3D for calculating the confusion matrix. I am wondering if you implemented the code for calculating the confusion matrix by yourselves? Would it be possible for you to share the file or code responsible for calculating the confusion matrix? If sharing is not possible, could you provide some guidance on how to calculate the confusion matrix in mmdetection3D?