Drop columns by patterns values in R

Question

I have a dataframe such as :

g1   g2   g3   g4   g5
2    0    1    0    1
2    1    1    0    1
2    1    1    2    1

and I would like to remove each column that have at least one 2 in its values.

and get a new df :

g2   g3   g5
0    1    1
1    1    1
1    1    1

Thanks for your help.

Answer 1

We can use colSums here:

df <- data.frame(g1=c(2,2,2), g2=c(0,1,1), g3=c(1,1,1), g4=c(0,0,2), g5=c(1,1,1))
df[, !colSums(df==2)]

  g2 g3 g5
1  0  1  1
2  1  1  1
3  1  1  1

The idea is to include all rows from the original data frame, but only include those columns which never have a value of 2. In that case, the call to colSums() would be zero, which is logically equivalent to false in R.