How to replace an specific number (such as 9 or 99) for a missing value?

[alfonso_gijon]

Hi, I have missing values of my columns specified by values such as 9 or 99. I would like to replace those values for missing value or an empty cell. How could I do it?

It would be interesting for me also the same transformation from the string ‘?’ to missing value.

Thanks in advance

[marzukim]

hi @alfonso_gijon welcome to the knime community.
perhaps you could provide the community with a sample of your columns missing data. this would allow them to see the pattern and try to understand and provide the optimal solution.

mm

[alfonso_gijon]

Here you can see how my data are:

I have different instances of data with month, weekday and hour as attributes. WEEKDAY ranges from 1 to 7 (9 corresponds to missing value) while HOUR ranges from 0 to 23 (99 corresponds to missing value).

I would like to replace those specific integer values by missing value or by an empty space. How could I do it?

The node Rule Engine with the rule $HOUR$=99 => " " is not working properly. It fills everything with missing value

[gonhaddock]

Hello @alfonso_gijon and welcome to the KNIME forum

You can address nulls with the Rule Engine node, avoiding alternative rule:

NOT $target_column$ = -999.99 => $target_column$

salu2