Missing Value: Add Option to convert to Null

Feedback & Ideas
1

Hi,

in order to provide better reports, I want to suggest adding the option to convert missing to null.

image

Using the String Manipulation to try to exploit toNull doesn’t work as, upon converting back to Int, null becomes missing again. Though, the red question mark is rather obtrusive and filling all cells with zero doesn’t help to focus either.

Best
Mike

2

Hi @mwiegand , can you elaborate a little. In my mind Null and Missing Value are the same thing in KNIME terms.

The String Manipulation toNull() function that you mention generates Missing Value in place of empty strings. So are you talking about having a configurable option to display/render Missing Values differently (e.g. as blank cells for additional clarity instead of the question marks)? I can certainly see that for some use cases, especially for numeric data, having blank cells rather than red question marks as an option might be beneficial.

3

Hi @takbb,

it’s about creating reports that are more easy to understand by reducing what is not necessary or even misleading. The red question mark in the PDF reports, but also the Interactive view, is visually highly distracting and indicating an error.

If you would share a report with a client who does not know that this is “just fine”, he’d get confused. Display a zero isn’t a proper solution either as it too diverges focus from the actual numbers.

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4

Hi @mwiegand , thanks for the clarification. So it is about being able to choose how the missing values are displayed. I was confused by the term “convert missing to null” as to me they are the same thing in data terms, but I understand now that you mean the ability to convert the output to a blank/null, which I totally get.

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5

Hi @mwiegand ,

yes, this makes a lot of sense. The salient question marks are good for data exploration, when missing values typically are caused by some problems in the data. For reports other representations raising less attention are more suitable in many cases. We envisioned such functionality for the new Number/String Format Manager nodes, but did not get to implement it yet. (In the String Format Manager, you can already find a setting to replace empty strings with custom values.)
I created a ticket (internal reference UIEXT-2199) to raise awareness with the developers.

Thanks for reporting,
nan

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