How to subset rows from a data frame with comparison operators in R
You want

data_frame[data_frame$X1 &gt; 30, c("X1","X2","X4")]


that will just print it, you probably want to update data_frame or store it in something else:

data_frame = data_frame[data_frame$X1 &gt; 30, c("X1","X2","X4")]


also you probably want to try asking this on StackOverflow, or reading a bit more basic R documentation because it should be well covered. Its a bit simple to be "data science".