Count features for different ids in columns in R in faster way

Question

I am trying to process a 20 GB data file in R. I have 16 gigs RAM and i7 processor. I am reading the data using :

y<-read.table(file=\"sample.csv\", header =          


        

Answer 1

For your example:

apply(sign(table(y)), 1, sum)
21 22 23 
 4  4  2