Column Expressions - discrepancy between evaluation and actual computed value

[toscano]

Hello KNIME Team,
I noticed a discrepancy in between the evaluation of a formula and the actual computed value showed in the table, in the Column Expressions node. More specifically, when I use the rowIndex() function. See below:

And the actual table.

[takbb]

@toscano

rowIndex()

Hi @toscano, I believe this is a long-standing bug in Column Expressions and yes there is a discrepancy of the returned row index: when evaluate on first row is pressed it returns 1 but in execution returns the correct rowindex (i.e. 0) for first row, which can cause unexpected behaviour for certain use cases such as yours.

For historic references see:

Column Expressions rowIndex function Evaluated and executed values differ

Hi. When the Column Expressions node is used to add a column of row indexes using the rowIndex function, the “Evaluate on first row” button in the dialog returns zero. However when executed, the value in the first row of the output table is 1, so the two values disagree. (By the way I would have expected the row index in the output table to be zero-based). [image] [image] Thanks Don

RowIndex calculated wrongly?

I just stumbled across something what i think is a bug. In the preview the RowIndex in a column Expression node for the first row is 0: [RowIndex_preview] Later in the output table it is 1: [RowIndex_table] Has something changed/gotten ouf order with an update? I looked up an old documentation (of mine) where the screenshot looks like: [Screenshot older] I can not say from when exactly the screenshot is nor what thenode was - it’s cut of on top and i don’t remember. i realized this today…

Column Expression: Row Index starts with 1 but not 0

Hi, I happen to notice a potentially problematic inconsistency in the Column Expression node. When accessing the Row Index using rowIndex() [image] This has been flagged already back in April 2020 and the comment from @ScottF indicates it is present since earlier as there is a ticket AP-11609 Why hasn’t this been addressed? I believe the fix should be rather straight forward but please prove me wrong about this. Back when I managed a global ecommerce infrastructure this kind of bug would …

I’m guessing that fixing this one didn’t get a priority!