Question

I have a data.frame in R. I want to select rows that have a specific value in one of three columns. I have a large data.frame, but what I need is like the example below:

seller<-c("Mary", "Bill", "Jeff", "Paty", "Paul", "Criss")
c1<-c(1,2,1,1,3,1)
c2<-c(1,1,1,1,2,1)
c3<-c(1,1,3,1,1,1)
data<-data.frame(seller, c1, c2, c3)

>data
       seller c1 c2 c3
   1   Mary  1  1  1
   2   Bill  2  1  1
   3   Jeff  1  1  3
   4   Paty  1  1  1
   5   Paul  3  2  1
   6   Cris  1  1  1

I want to select the rows that have values ​​equal and greater than 2, like this:

>data
       seller c1 c2 c3
   1   Bill  2  1  1
   2   Jeff  1  1  3
   3   Paul  3  2  1

Thanks for the help!

Answer 1

I don’t know if this is the best way to do it, but you can use rowSums and which to subset, as in the following example:

data[which(rowSums(data[-1]) > ncol(data[-1])), ]
#   seller c1 c2 c3
# 2   Bill  2  1  1
# 3   Jeff  1  1  3
# 5   Paul  3  2  1

A more direct alternative is:

data[which(apply(data[-1], 1, function(x) any(x >= 2))), ]

I’ve used data[-1] to remove the names of the sellers (as they are character strings). Then, apply with margin 1 applies the specified function by row (margin 2 would do the same by column). The function is any(x >= 2), which returns TRUE or FALSE for each row; with which, we can subset the rows for which the return was TRUE.