a<-data.frame(cell<-c( 70,26.171255,79,18.725711,129,17.130182,                          7.073919))

for (i in 1:nrow(a)) {
      a[i,1] <- ifelse(a[i,1] %in% c(17.130182,18.725711,26.171255), NA,a[i,1])
    }

a<-data.frame(value$tobinsq)