General a column from row-wise totals in R-CodePudding

I have a table that looks like this:

df <- tribble(
  ~name, ~point, ~time,
  "A", 1, 1,
  "B", 1, 1,
  "W", 2, 1,
  "A", 3, 2,
  "B", 1, 2,
  "W", 4, 2,
)

# A tibble: 6 x 3
  name  point  time
  <chr> <dbl> <dbl>
1 A         1     1
2 B         1     1
3 W         2     1
4 A         3     2
5 B         1     2
6 W         4     2

And I want to turn the value of the point column into the value of every entry in a new column, specifically where the name is equal to W, like so:

# A tibble: 6 x 4
  name  point  time W_point_value
  <chr> <dbl> <dbl>         <dbl>
1 A         1     1             2
2 B         1     1             2
3 W         2     1             2
4 A         3     2             4
5 B         1     2             4
6 W         4     2             4

I know I can use filter to get the result but I'm struggling to append it into a new column due to improper sizing.

Thank you

CodePudding user response：

You can do this:

df %>% 
  group_by(time) %>% 
  mutate(W_point_time = point[name == "W"])

# A tibble: 6 x 4
# Groups:   time [2]
  name  point  time W_point_time
  <chr> <dbl> <dbl>        <dbl>
1 A         1     1            2
2 B         1     1            2
3 W         2     1            2
4 A         3     2            4
5 B         1     2            4
6 W         4     2            4