Creating multiple proportion table in R dataframe

Question

I've the following table

Result_Group	Review
A	1
B	4
A	1
C	1
D	5
D	4
E	5
C	1
C	2
A	2
B	3
E	2

df = structure(list(Result_Group = structure(c(1L, 2L, 1L, 3L, 4L, 4L, 5L, 3L, 3L, 1L, 2L, 5L), .Label = c("A", "B", "C", "D", "E"
              ), class = "factor"), Review = c(1L, 4L, 1L, 1L, 5L, 4L, 5L, 1L, 2L, 2L, 3L, 2L)), 
              class = "data.frame", row.names = c(NA, -12L))

Does anyone know how can create a table for the proportion of the review for each group? Currently I'm doing it group by group and it's taking quite a while just to subset the data.

i.e. the table as follows:

Review	A	B	C	D	E
1	0.67	0	0.67	0	0
2	0.33	0	0.33	0	0.50
3	0	0.50	0	0	0
4	0	0.50	0	0.5	0
5	0	0	0	0.5	0.50

Thanks!

Answer 1

You can do:

library(tidyverse)

df |> 
  group_by(Result_Group) |> 
  count(Review) |> 
  mutate(prop = n/sum(n)) |> 
  ungroup() |> 
  select(-n) |> 
  pivot_wider(names_from = Result_Group,
              values_from = prop,
              values_fill = 0)

# A tibble: 5 x 6
  Review     A     B     C     D     E
   <int> <dbl> <dbl> <dbl> <dbl> <dbl>
1      1 0.667   0   0.667   0     0  
2      2 0.333   0   0.333   0     0.5
3      3 0       0.5 0       0     0  
4      4 0       0.5 0       0.5   0  
5      5 0       0   0       0.5   0.5

Answer 2

Here is a tidy approach using dplyr and tidyr

library(dplyr)

df %>% 
  # Add count values (all equal to 1)
  mutate(count = 1) %>% 
  
  # Pivot wider to get A, B, C.. as column names, and sum of count as values
  tidyr::pivot_wider(
    id_cols = Review,
    names_from = Result_Group,
    values_from = count,
    values_fn = sum,
    values_fill = 0 # NAs are turned into 0
  ) %>% 
  
  # Mutate to get fractions instead of count
  mutate(
    across(
      -Review,
      ~ .x / sum(.x)
    )
  ) %>% 
  
  # Sort by review
  arrange(Review)


#> # A tibble: 5 × 6
#>   Review     A     B     C     D     E
#>    <int> <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1      1 0.667   0   0.667   0     0  
#> 2      2 0.333   0   0.333   0     0.5
#> 3      3 0       0.5 0       0     0  
#> 4      4 0       0.5 0       0.5   0  
#> 5      5 0       0   0       0.5   0.5

^{Created on 2022-03-22 by the reprex package (v2.0.1)}