data manupilation

[Jason1]

Hi there, I'm a new learner in R. had a trouble to sum the data, which showed below
|bwgp|smoke|value|
|3|0|35|
|3|1|11|
|2|0|29|
|2|1|17|
|1|0|22|
|1|1|16|
|0|0|29|
|0|1|30|
this excel data is named as bwtsmk.
to obtain the sum for value by smoke status, I used the code below, but failed

smk0<-sum(bwtsmk$(value & smoke=0))

which code should I use to get it. appreciate much if someone can help.

Jason

[technocrat]

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)}

[nirgrahamuk]

grateful to Technocrat for providing example data

@Jason1

to obtain the sum for value by smoke status

library(tidyverse) # install this package to have access to the library
group_by(dat, smoke) %>% summarise(value=sum(value))
# A tibble: 2 x 2
  smoke value
  <dbl> <dbl>
1     0   115
2     1    74

[Jason1]

Thanks for this, but this is not what I wanted. I've imported the excel data into R and got the same sum. what I want to get is the sum by smoke status, ie, the sum of 'value' for smoke=0 and that for smoke=1, respectively.

[Jason1]

sorry, I did see the code at the end.
thanks,
jason

[Jason1]

@nirgrahamuk

group_by(dat, smoke) %>% summarise(value=sum(value))

Hi there, here is another question related to this one, if I want to add another column as 'proportion' in the table as the result of 'value' divided by the sum by smoke status, how should I do? if possible, I would appreciate if some books or websites can be recommended on these basics.
Thanks,
Jason

[nirgrahamuk]

group_by(dat, smoke) %>% 
  summarise(value=sum(value)) %>% 
  mutate(proportion=value/sum(value))

this is a good resource

Welcome | R for Data Science

[Jason1]

Thanks for this helpful information!
Jason