Counting how many times a string shows in a column in R-CodePudding

Let's say I have the following dataframe:

 X1           X2      

 Fox          A/B/C/D
 Duck         A/B/E/F
 Bird         A/E/G

And I want to count how many times the values in X2 shows up (without manually entering the letters to count).

The result would be:

X1   X2 (counts)
A    3
B    2
C    1
D    1
E    2
F    1
G    1

I have no idea on how to begin with this :(

CodePudding user response：

Split the column at the /, get the frequency count with table and stack to a two column data.frame in base R

stack(table(unlist(strsplit(df1$X2, "/", fixed = TRUE))))[2:1]

-output

  ind values
1   A      3
2   B      2
3   C      1
4   D      1
5   E      2
6   F      1
7   G      1

df1 <- structure(list(X1 = c("Fox", "Duck", "Bird"), X2 = c("A/B/C/D", 
"A/B/E/F", "A/E/G")), class = "data.frame", row.names = c(NA, 
-3L))