Question

I’m trying to implement a function which takes a dynamic subset based on a list of column names of any length

The static code is:

s <- c("s0","s1","s2")
d.subset <- d[ d$s0 > 0 | d$s1 > 0 | d$s2 > 0,] 

However, I want to generate the d$s0 > 0 | d$s1 > 0 | d$s2 > 0 part based on s. I tried as.formula() for generating it, but it gave me an “invalid formula” error.

Answer 1

An example data frame:

d <- data.frame(s0 = c(0,1,0,0), s1 = c(1,1,1,0), s2 = c(0,1,1,0))

s <- c("s0","s1","s2")

Here is an easy solution with rowSums:

d[as.logical(rowSums(d[s] > 0)), ]

The result:

  s0 s1 s2
1  0  1  0
2  1  1  1
3  0  1  1