R: Find the unique count (frequency) of a column by patient per treatment group

Question

I have a dataset patient data. I want to get the frequency by col3 per unique col1 across col2. Col2 is a treatment group and need to derive the unique counts of type of injection present in col 1 per patient in COL3. Need help with R code to calculate the same.

Answer 1

Quite unclear, but I guess something like this?

library(tidyverse)

df <- tibble(
  COL1 = paste("Type", sample(LETTERS[1:10], 100, replace = TRUE)),
  COL2 = paste("Injection", sample(1:10, 100, replace = TRUE)),
  COL3 = paste("Patient", sample(1:10, 100, replace = TRUE))
) %>% 
  relocate(COL3)

df %>% 
  count(COL3, COL1, COL2)

# A tibble: 98 × 4
   COL3      COL1   COL2            n
   <chr>     <chr>  <chr>       <int>
 1 Patient 1 Type B Injection 2     1
 2 Patient 1 Type B Injection 8     1
 3 Patient 1 Type C Injection 6     1
 4 Patient 1 Type C Injection 9     1
 5 Patient 1 Type D Injection 9     1
 6 Patient 1 Type E Injection 6     1
 7 Patient 1 Type F Injection 8     1
 8 Patient 1 Type G Injection 1     1
 9 Patient 1 Type G Injection 6     1
10 Patient 1 Type I Injection 1     1
# … with 88 more rows