multiplying one column in tibble by each element in vector to produce multiple new tibbles-CodePudding

Given the tibble:

c1 <- c(1,2,3)
c2 <- c(4,5,6)
c3 <- c(7,8,9)
d1 <- as_tibble(data.frame(c1,c2,c3))

# A tibble: 3 × 3
     c1    c2    c3
  <dbl> <dbl> <dbl>
1     1     4     7
2     2     5     8
3     3     6     9

and the vector

v1 <- c(1,2,3)

I would like a tidyverse method to multiply c3 by each element in the vector to produce three new tibbles that look like this:

# A tibble: 3 × 3
     c1    c2    c3
  <dbl> <dbl> <dbl>
1     1     4     7
2     2     5     8
3     3     6     9

# A tibble: 3 × 3
     c1    c2    c3
  <dbl> <dbl> <dbl>
1     1     4     14
2     2     5     16
3     3     6     18

# A tibble: 3 × 3
     c1    c2    c3
  <dbl> <dbl> <dbl>
1     1     4     21
2     2     5     24
3     3     6     27

I got as far as this:

d1 %>%
    mutate(outer(c3, v1, FUN = "*"))

# A tibble: 3 × 4
     c1    c2    c3 `outer(c3, v1, FUN = "*")`[,1]  [,2]  [,3]
  <dbl> <dbl> <dbl>                          <dbl> <dbl> <dbl>
1     1     4     7                              7    14    21
2     2     5     8                              8    16    24
3     3     6     9                              9    18    27

but it is not really a tidy way and is still one object. What are some better methods?

CodePudding user response：

map (or the base R equivalent lapply) are usually good places to start when you want to output a list:

library(purrr)
library(dplyr)
map(v1, ~ d1 %>% mutate(c3 = .x * c3))

[[1]]
# A tibble: 3 × 3
     c1    c2    c3
  <dbl> <dbl> <dbl>
1     1     4     7
2     2     5     8
3     3     6     9

[[2]]
# A tibble: 3 × 3
     c1    c2    c3
  <dbl> <dbl> <dbl>
1     1     4    14
2     2     5    16
3     3     6    18

[[3]]
# A tibble: 3 × 3
     c1    c2    c3
  <dbl> <dbl> <dbl>
1     1     4    21
2     2     5    24
3     3     6    27

In base R:

lapply(v1, \(x) {d1[3] <- d1[3]*x; d1})

CodePudding user response：

Using transform in base R

 lapply(v1, \(x) transform(d1, c3 = c3 *x))

-output