Questions about "Remember", "Recall" and "Generate Attributes" Operators

RichardtheboyRichardtheboy Member Posts: 7 Contributor I
edited November 2018 in Help


1. The "Remember" and "Recall" operators seem like malfunctional (Perhaps I made some mistakes on setting up their names?). In my process, two "Remember" and one "Recall" operators were used, all of them are named as "T100", but when the "Recall" operator recall the information which is stored in "Remember", the Exampledata changed from "1 example, 6 Regular Attributes" to "1 example, 1 Regular Attributes". Which part of my process gone wrong??


2. In the Loop operator, I have put a "Generate Attributes" operator in order to generate extra dates (In my example, which are the dates after 19/09/16). The function description I have wrote was "date_add(Date,30,DATE_UNIT_DAY)", but after I run the process, there wasn't any new dates being generated and only the last date (19/09/16) was being repeated. May I know which part of my process gone wrong and how may I solved it please?



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    MartinLiebigMartinLiebig Administrator, Moderator, Employee, RapidMiner Certified Analyst, RapidMiner Certified Expert, University Professor Posts: 3,518 RM Data Scientist

    Dear Richard,


    both questions are kind of hard to answer. Remember and Recall are variables you can use in a process. I could imagine that - by accident - you stored new content into that variable. In this case the old content gets deleted? Having an example process would be very useful. Same for the second question, Could you maybe provide an example?



    - Sr. Director Data Solutions, Altair RapidMiner -
    Dortmund, Germany
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    sgenzersgenzer Administrator, Moderator, Employee, RapidMiner Certified Analyst, Community Manager, Member, University Professor, PM Moderator Posts: 2,959 Community Manager

    Just adding a few more thoughts to Martin's reply...


    - Be very careful when you use Remember and Recall with the "Remove from Store" checkbox.  The default is yes and this is not always what I want.  And of course if you "remember" an example set that has the same name as a previous example set that you have "remembered", it will be overwritten.


    - As for your loop question, this happens to me all the time.  It has to do with the output wiring of loop operators.  I personally find it very confusing because some loop operators go through their loop and output the same set as was inputted (but of course with whatever changes you wanted), others don't.  I almost ALWAYS use "remember and recall" with loop operators to avoid this whole issue.  I use a Remember operator before the loop, Recall inside the loop, do what I need to do in the loop, Remember again inside the loop, and then finally Recall the result outside the loop.  If you do it this way, you (almost) cannot get tangled up.  And in this case the "Remove from Store" checkbox should remain checked.


    Hope that helps,


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    Thomas_OttThomas_Ott RapidMiner Certified Analyst, RapidMiner Certified Expert, Member Posts: 1,761 Unicorn

    Remember and Recall are handy in certain situations but I tend to avoid them if I can.


    Generate Attributes on the othe hand is a life saver. I call it the RapidMiner Swiss (German?) Army knife. 

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