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Newb question: grouping selected nominal values

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Newb question: grouping selected nominal values

New to RapidMiner and Data Mining in general, so apologies if this is a stupid question.

I have a data set with a type attribute and there are three main types and about 15 minor types.

I want to rename nearly all the minor types to 'other'. I've managed to do this using the AttributeValueMapper (though it seems a bit cumbersome, having to an AttributeValueMapper for each of the types -- is there a better way?). However, when I come to plot the options I run into difficulties, particularly with the legend, getting the error:

"Plotter: cannot draw nominal legend since number of different values is too high (more than 20)! Using numerical legend instead." The problem seems to be that it wants to plot the types that have been replaced by 'other

How do I 'lose' the possible nominal values that have now been converted to 'other'? Is it possible?

Thanks
Chris
1 REPLY
Moderator

Re: Newb question: grouping selected nominal values

Hi Chris,

ctagg wrote:

I want to rename nearly all the minor types to 'other'. I've managed to do this using the AttributeValueMapper (though it seems a bit cumbersome, having to an AttributeValueMapper for each of the types -- is there a better way?).


We recently extended the [tt]AttributeValueMapper[/tt]. It is now capable of handling multiple mappings at once, i.e. you only need one [tt]AttributeValueMapper[/tt] to replace different values.

ctagg wrote:

How do I 'lose' the possible nominal values that have now been converted to 'other'? Is it possible?


Actually, the extended [tt]AttributeValueMapper[/tt] accomplishes this as well. To use the extended operator, you simply have to check out the current developer version from our CVS. You will find an explanation on how to do that using the Eclipse IDE at

http://rapid-i.com/content/view/25/48/

Regards,
Tobias