R How to use lapply properly

Question

Hi folks,

I have a question concerning the lapply function in R. I want to calculate cohen`s kappa (fast) for a data frame with 100+ variables (2 raters) (which looks like this (v1_r1; v1_r2; v2_r1;...). Do you know a way to solve this problem? Or know another method?

I tried /and failed with this: lapply(dat, kappa2(dat %>% select (dat[seq(2, length(dat), 2)], dat[seq(3, length(dat), 2)])))

Merci beaucoup!!!!