Generate Aggregation and Group by

aruberutou
aruberutou New Altair Community Member
edited November 5 in Community Q&A
Hello,

I would like to count each unique item in a column, and create a new column with the corresponding count information for each item.

In excel, I would simply use =countif(ColumnA, ColumnA(i)) and copy down.

I expected that to be equally simple in RapidMiner; perhaps using GenerateAttribute. However, this is no "group by" function, and so my count column always returns "1" for each value.

Am I overlooking something?

Answers

  • aruberutou
    aruberutou New Altair Community Member
    Okay,

    I feel silly. Its seems a simple solution was to multiply the data, aggregate one thread, then rejoin using the aggregated attribute as the key.

    Its still messier than I would have hoped, but perfectly usable, I guess.

    Nevertheless, please let me know if I am missing something.
  • MartinLiebig
    MartinLiebig
    Altair Employee
    Your solution would be my way as well.