CODEWITHSUNDEEP
rnormalization
AbeeCrombie
AbeeCrombie

Reputation: 607

Scale only non zero elements in Vector

I have a sparse vector/column in data table that I am using as a feature which has mostly zero's and then a few non zero elements. I wanted to scale/normalize the vector, but only for the non zero entries.

Any thoughts how to efficiently implement this.

Thanks in advance 

c(0,0,0,0,0,0,0,10,20,5,0,0,0,0,0,0,5,3,1,30,0,0,0,0,0,0,0,1,1,0,0,0,0,0)

returns 0's and then I guess the abosolute value of the scaled numbers

Upvotes: 1

Views: 611

Answers (1)

akrun
akrun

Reputation: 887048

We create a logical index ('i1') and scale the vector based on it.

i1 <- v1!=0
v1[i1] <- scale(v1[i1])

data

v1 <- c(0,0,0,0,0,0,0,10,20,5,0,0,0,0,0,0,5,3,1,30,0,0,0,0,0,0,0,1,1,0,0,0,0,0)

Upvotes: 3

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