LDA,QDA and RDA operators from RM 7.1 available in RM9 ....what would be the best way to do it?
At some point the behaviour of these operators has changed in more recent versions of Rapidminer. I am losing repeatability. Of all the learners I tested, these are the ones that did not give me the same results between RM7.1 and RM8+. At least on my data. The results are the same if repeated on each version of Rapidminer independently so the process is not introducing any randomness. Unfortunately, I get consistently better results from the versions in 7.1 than in newer versions. I am assuming that I could create an extension for these older operators. Is there a better way?
Kind regards,
Alex
Alex
Best Answer
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jczogalla Employee-RapidMiner, Member Posts: 144 RM Engineering
Hi @hughesfleming68,
I think the reason is that before 7.5 there was an error in RDA which ignored the alpha parameter, see the release notes (under bugfixes).
Until 7.5, RDA was equivalent to QDA. Also, until 7.4 it seems that LDA and QDA were switched (see release notes again).
Regards,
Jan
1
Answers
Hi @hughesfleming68,
cant you just change the compatibility level of the operator?
Best,
Martin
Dortmund, Germany
Hi Martin,
I think the compatibility level only gives me the option of 7.4. I did look at the source code at some point and I think the change occured from 7.11 to 7.4. I will have to check this again. In the mean time, I will try 7.4 and see if that makes a difference. It had slipped my mind to check that so thanks for reminding me. I hope that does the job!
Regards,
Alex
Thanks for the explantion Jan. I am going to have to try some different data. At the moment in 8.2, RDA with alpha =1 which should give me LDA gives me different results than the LDA operator. If I run a grid for alpha between 0 and 1 with RDA in 0.1 increments, I get the same results for all values of alpha which suggests that RDA is still not taking alpha into consideration.
I will recheck my old processes with the idea that QDA and LDA were switched and get back to you if there is still some confusion.
Kind regards,
Alex
Hi Jan, your explanation helped a lot. RDA alpha is working properly on a different data set. In my old processes, the old RDA was ignoring alpha. This explains the differences I was seeing.
regards,
Alex
Hi Alex,
glad to hear it helped. Also check the compatibility level on those operators, because I guess in your old processes, they are on 7.4.
Cheers
Jan