Change value by group based in reference within group - r

Question

given a table with defined groups where within each group
I have just 1 reference (query) I'd like to change all values of a column
based in value of the reference.
This values are just 1 or -1.
The idea is:
- if reference is equal to 1 so keep all values as it are
- but if reference is -1, so all values should be multiplied by -1, so that way reference became to be 1 and the items with value 1 became to be -1
- Also, modified groups should have opposite order
I'm trying to do this way:
library(tidyverse)
item <- c("a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l")
grou <- c(1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 4)
quer <- c(0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0)
dir <- c(1, 1, 1, -1, 1, 1, 1, -1, 1, -1, -1, -1)
ds <- tibble(item = item,
group = grou,
query = quer,
direction = dir)
ds %>%
group_by(group) %>%
mutate(
direction = ifelse(
direction[query == 1] == 1, direction, (-1 * direction)
)
)
So this
# A tibble: 12 x 5
# Groups: group [4]
item group query direction
<chr> <dbl> <dbl> <dbl>
1 a 1 0 1
2 b 1 1 1
3 c 1 0 1
4 d 2 0 -1
5 e 2 1 1
6 f 2 0 1
7 g 3 0 1
8 h 3 1 -1
9 i 3 0 1
10 j 4 0 -1
11 k 4 1 -1
12 l 4 0 -1
Should became this
# A tibble: 12 x 5
# Groups: group [4]
item group query direction
<chr> <dbl> <dbl> <dbl>
1 a 1 0 1
2 b 1 1 1
3 c 1 0 1
4 d 2 0 -1
5 e 2 1 1
6 f 2 0 1
7 i 3 0 -1
8 h 3 1 1
9 g 3 0 -1
10 l 4 0 1
11 k 4 1 1
12 j 4 0 1
But it is not working.
Thanks in advance

Answer 1

Here is a way to do it:
ds %>%
rowid_to_column("id") %>%
group_by(group) %>%
mutate(tmp = max(query * direction) - 0.5,
direction = tmp * 2 * direction) %>%
arrange(id * tmp, .by_group = TRUE) %>%
select(-c(id, tmp))
The result:
# A tibble: 12 x 4
# Groups: group [4]
item group query direction
<chr> <dbl> <dbl> <dbl>
1 a 1 0 1
2 b 1 1 1
3 c 1 0 1
4 d 2 0 -1
5 e 2 1 1
6 f 2 0 1
7 i 3 0 -1
8 h 3 1 1
9 g 3 0 -1
10 l 4 0 1
11 k 4 1 1
12 j 4 0 1