rimusolem opened a new issue #9865: Confusing behavior of some evaluation 
metrics
URL: https://github.com/apache/incubator-mxnet/issues/9865
 
 
   ```python
   mse = mx.metric.create('mse')
   x = mx.nd.array([[1,2,3,4]])
   mse.update(x, x + 0.1)
   print(mse.get()) # 2.509999 ...? I expected 0.01.
   ```
   According to the API document, the `update` method of evaluation metrics 
takes lists of NDArrays. So the first example uses the API not correctly, but 
there is no errors or warnings. Many functions of mxnet allow "an NDArray or a 
list of NDArrays" as an argument and an NDArray is equivalent to a list with a 
single element. So this behavior of the MSE metric is confusing and errorprone. 
Please raise an error or fix the implementation for NDArray arguments.
   
   ```python
   mse = mx.metric.create('mse')
   x = mx.nd.array([1,2,3,4]) 
   mse.update([x], [x + 0.1]) # lists of 1D arrays.
   print(mse.get()) # 2.509999 ... ?
   ```
   The result of the second example is not understandable. I believe the result 
should be 0.01 in this case also. Or, if 1D array is not acceptable, it must 
raise an error.
   
   MAE and RMSE also show similar behavior.
   

----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on GitHub and use the
URL above to go to the specific comment.
 
For queries about this service, please contact Infrastructure at:
us...@infra.apache.org


With regards,
Apache Git Services

Reply via email to