Set Operator not functioning as expected

KNIME Analytics Platform
1

I don't understant how the Set Operator node works.  I tried simplifying my dilemma to a test case using a one-row table with the following sets:

Column1 Column2
[red,blue,green,orange] [blue,yellow]

I feed the same table into both input ports of the Set Operator node, and select each respective column in the configuration. I selected the "Intersection" operation, and I'm expecting it to generate a third column with [blue]

But instead, I get a blank table.

When I change the operation to "Union", instead of getting a new set with all the elements, I get an output with two rows:

Column1 | Column2
[blue,yellow]
[red,blue,green,orange]

Can someone explain the logic behind these outputs?

Thanks,

--George

 

2

Hi George,
the set operator does not work on Collection cells. It handles the complete column as a set. So if you would ungroup the two columns and execute the set operator with the ungroup columns it should work as expected. If you want to perform a set operation on collection columns row by row you can use the Column Aggregator node.
Bye,
Tobias