[R] Deleting rows satisfying a certain condition (sum of some colums>2)

I have a huge matrix and need to delete certain rows. What I need to do is: 1.In each row, calculate the sum of jth column and (J+2)th column 2. If the sum is greater than 2 then that row needs to be deleted. I have a sample matrix and my codes here. It does remove some rows but when it does, it

Re: [R] parameters for lbfgsb (function for optimization)

I think I did not make myself clear when I asked about lbfgsb (function for optimization) yesterday. I'm writing my functions in C but actual calculation will be done in R by using .Call. To be able to use lbfgsb (using the interfaces defined in header 'R_ext/Applic.h') , I need to supply my funct