H2O Cross Validation Loop Start node wants nominal values

KNIME Analytics Platform
1

Hi,

I have difficulties configuring the H2O Cross Validation Loop Start node. It keeps complaining that there are no nominal value columns in my input table (a H2O frame). This is indeed correct, I only have doubles, but surely this should be accepatable input? The H2O Cross Validation exampple workflow works fine though, here I can change the configuration of the H2O Cross Validation Loop Start node.

Please advice.

Thanks/Evert

1 Like
2

Hi @evert.homan,

I have looked into it and this is definitely a bug. Thanks for the report!
A workaround is to add a temporary nominal column to configure the node. Once it’s configured, the column can be removed.

Cheers
Simon

1 Like
3

Hi Simon,

Which node should I use for the double to nominal conversion, and where should it be inserted: before or after the H2O Table to frame node?

Thanks/Evert

4

You could use the “Constant Value Column” node before the “H2O Table to Frame” node to append a String column.

5

This will just append an empty string column…what use is that?

6

There is currently a bug that any kind of nominal value column is required. appending an empty one is fine if you don’t use it for stratified sampling. having that said, we already fixed the bug and will release it soon :slight_smile:
Sorry for the trouble,

Christian

2 Likes
7

Thanks for your response, I now got it to work by inserting the Constant Value Column.

I also noted that the training and test frame output of the H2O Cross Validation Loop Start node appear to get mixed up, since the test frame size is always larger than the training frame size. I believe this should be the other way around?

Cheers/Evert