Error: unexpected '[' in r -

i have error

> (i in 1:(cutoff_size-1)){work$group[i]=rep(c(0,1),c([i]-1,cutoff_size-[i]-1))} error: unexpected '[' in:"for (i in 1:(cutoff_size-1)){work$group[i]=rep(c(0,1),c([" 

'cutoff_size' numeric.

how can solve problem?

for (i in 1:(cutoff_size-1)){work$group[i]=rep(c(0,1),c(i-1,cutoff_size-i-1))} 

this you're looking for.

[] used refer position in array/data table/list. if you're using in mathematical operation, not need [] around i.