GroupBy - Covariance

Hello everyone,

I have a problem using the GroupBy Node with Aggregation Covariance.

I have the following dataset:

Now I want to determine the covariance between the columns Lead_time and Repair_time for each Product. In this small example Product G123 has the values for Lead_time: 120, 118 and the Repair_time_ 20.0, 18.6 and so on. (In reality there are thousands of values for each Product)

I thought that I could select Product as Group (in GroupBy Node) and Covariance as Aggregation (With the additional setting: In the Colum Repair_time I set the Paramater Lead_time) . That gave me the following error:

Execute failed: Computing 'Covariance' on column 'Repair_time' failed. Error: sample contains 1 observed points, at least 2 are required.

I didn't found another option for the Observation of two points.

Maybe there is another possible (or better fitting) solution?!

Thanks and Greetings,

David