CODEWITHSUNDEEP
r
Doppler
Doppler

Reputation: 65

Normalizing data frame while holding a categorical column out

very new to r.

I am trying to normalize multiple variables in matrix except the last column which has a categorical factor variable (in this case good/notgood).

I there any way to normalize the data without affecting the categorical column? I have tried to normalize while keeping the categorical column out, but can't seem to be able to add it back again.

minimum <- apply(mywines[,-12],2,min) 
maximum <- apply(mywines[,-12],2,max) 
mywinesNorm <- scale(mywines[,-12],center=minimum,scale=(maximum-minimum))

I still need the 12th column to build supervised models.

Upvotes: 0

Views: 547

Answers (1)

G5W
G5W

Reputation: 37661

The short version is that you can simply reattach the column using cbind. However, it is just a little more complicated than that. scale returns a matrix not a data frame. In order to mix numbers and factors, you need a data.frame, not a matrix. So before the cbind, you will want to convert the scaled matrix back to a data.frame.

mywinesNorm = cbind(as.data.frame(mywinesNorm), mywines[ ,12])

A different approach would be to just change the data in place:

mywines[ ,12] = scale(mywines[ ,12])

Upvotes: 1

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