[R] how to loop over a group of variables?

[DEEPANKAR BASU]

Hi All,

I have a data frame with a group of variables named b1, b2, b3, ..., b18. These variables take the value 1, 2 or NA. For each observation, I want to do some computation by looping over the values for the group of variables: b1 to b18. In STATA I would do:

forval i=1/18 {
  --- use b`i' for computation ----
}

How can this be done in R?

Deepankar