Representing a class by negative number for training in GBM in R

Question

I have already generated a huge train file of ~1GB in which the ground truth is one of 4 classes {-1,0,1,2}. Yes, I agree that I could have done it using 3 instead of -1, but for some conventional reasons I used -1.

I want to use gbm in multinomial distribution mode. Whether it will create some problem with a negative representation or I can proceed with it?

score 0 · Accepted Answer · answered Jan 04 '14 at 19:22

0

The numerical values will be converted to factor variables and the labels will be {-1,0,1,2}. The -1 label will not be a problem.

You will not get a reference value for the "0" category unless you create the factor variable first with var <- factor(x, levels=c("0", "1", "2", "-1"). (I'm not sure that it would be meaningful to be talking about a reference level in this situation, but worried that you thought the would be a special significance for the "0"-level.)

answered Jan 04 '14 at 19:22

IRTFM

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"0" level is significant for me, where do I need to pass this created var? – Bit Manipulator Jan 05 '14 at 05:31
You are confusing me. I thought you had an analysis plan. – IRTFM Jan 05 '14 at 05:59
I am treating these values just as label for the class. – Bit Manipulator Jan 05 '14 at 09:54

Representing a class by negative number for training in GBM in R

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