"Cannot select Group by Attribute with Aggregation Operator"

cschie

Hi folks,

Trying to get into RapidMiner 5.0.

I encpuntered the following problem: I cannot select any attributes in the Aggregation operator. If I use the GUI it doesn't display any attributes to select. And if I try to modify the code by hand it get's reseted to this state
     <operator activated="true" class="aggregate" expanded="true" height="76" name="Aggregate" width="90" x="849" y="345">
       <list key="aggregation_attributes">
         <parameter key="Temp" value="average"/>
       </list>
     </operator>
without any group by attribute after execution.

Any advice? (Did I mention I was new... ;-) )

Thanks,
Chris

land

Hi,
since the beta version was published many bugs have been removed, so I'm not sure if there ever was a problem in this operator. But if you could send me the complete process, in the best case with data only being generated, so that I can execute it immediately, I can check if I can reproduce it or what's your problem.

Greetings,
  Sebastian

cschie

Hi Sebastian,

thanks for the reply.
It works with data generated. The metadata gets passed on. But I read fom Access and no metadata gets generated by "Read Access.output". You can reconstruct that simply by attaching a Read Access directly to a Aggregate operator.

I got the message "Cannot create example set meta data. File cannot be null." Though I assigned a file and specified all the parameters correctly. It gets read in by other operators which seem not to need specified meta data.

Probably something obvious...

Thanks,
Chris

land

Hi,
ok, thank you for this report. I will check this.

Greetings,
  Sebastian

land

Hi,
this is correct. For getting the meta data from an access file you would have to read it, but MetaData transformations must rely on quick operators, so that this is not possible. To avoid these problems, the repository was introduced. You could import the file, so that the meta data can be stored there for further use.

Greetings,
  Sebastian

cschie

Hi Sebastian,

thanks for the great help.

Yeah, the repository is really a milestone for Rapidminer ;-)

Chris