dat <- structure(list(
bwgp =
c(3, 3, 2, 2, 1, 1, 0, 0),
smoke =
c(0, 1, 0, 1, 0, 1, 0, 1),
value =
c(35, 11, 29, 17, 22, 16, 29, 30)),
class =
c("spec_tbl_df", "tbl_df", "tbl", "data.frame"),
row.names =
c(NA, -8L), spec = structure(list(cols = list(bwgp = structure(list(),
class =
c("collector_double", "collector")), smoke = structure(list(),
class =
c("collector_double", "collector")), value = structure(list(),
class =
c("collector_double", "collector"))), default = structure(list(),
class =
c("collector_guess", "collector")), skip = 1),
class = "col_spec"))
dat
#> bwgp smoke value
#> 1 3 0 35
#> 2 3 1 11
#> 3 2 0 29
#> 4 2 1 17
#> 5 1 0 22
#> 6 1 1 16
#> 7 0 0 29
#> 8 0 1 30
sum(dat$value)
#> [1] 189
sum(dat[3])
#> [1] 189
Created on 2020-03-31 by the reprex package (v0.3.0)