Conditional statements to separate rows

Question

I am converting between two programs that use different logic structures. The original program uses conditional statements to define probabilities. For example, if Condition_A = (1 OR 2 OR 3) AND Condition_B = (X OR Y) THEN Probability = 0.5. The table looks like this:

Condition_A  Condition_B     Probability
1, 2, 3      X, Y            0.5

The new program requires a separate line for each combination, like this:

Condition_A  Condition_B     Probability
1            X               0.5
2            X               0.5
3            X               0.5
1            Y               0.5
2            Y               0.5
3            Y               0.5

I have the top table and need to convert it into the bottom table. I am looking to write an R script to automate the conversion for ~2,000 conditional statements. I am totally stumped so I don't have any code to show what I have tried. TIA

Answer 1

Libraries

library(tidyverse)

Data

df <-
  tibble(
    condition_A = c("1,2,3"),
    condition_B = c("X,Y"),
    probability = .5
    
  )

Code

df %>% 
  separate_rows(condition_A) %>% 
  separate_rows(condition_B)

Output

# A tibble: 6 x 3
  condition_A condition_B probability
  <chr>       <chr>             <dbl>
1 1           X                   0.5
2 1           Y                   0.5
3 2           X                   0.5
4 2           Y                   0.5
5 3           X                   0.5
6 3           Y                   0.5

Answer 2

By separate_rows

df <- tibble::tribble(
  ~Condition_A,  ~Condition_B,     ~Probability,
  "1, 2, 3",      "X, Y",           0.5
  
)
df %>%
  separate_rows(., Condition_A) %>%
  separate_rows(., Condition_B)

  Condition_A Condition_B Probability
  <chr>       <chr>             <dbl>
1 1           X                   0.5
2 1           Y                   0.5
3 2           X                   0.5
4 2           Y                   0.5
5 3           X                   0.5
6 3           Y                   0.5