Thanks, new issue opened on GitHub here:

  
      github.com/pytorch/ignite
  
  
    
  
	  
  

  
    
      Documentation for ConfusionMatrix is thin on details, and error messages not informative 4
    

    
      
        opened 
        
          
        
        Oct 12, 2020
      
      


      
        
          
          nsinenian
        
      
    
  



  🐛 Bug description
Confusion matrix requires that y_pred and y are to have different dimensions (batch,num_classes) and (batch,), respectively. Getting this wrong...



    docs
    enhancement