R - Counting the number of a specific value in bins

Question

I have a data frame (df) like below:

Value <- c(1,1,0,2,1,3,4,0,0,1,2,0,3,0,4,5,2,3,0,6)
Sl <- c(1:20)
df <- data.frame(Sl,Value)    

> df
   Sl Value
1   1     1
2   2     1
3   3     0
4   4     2
5   5     1
6   6     3
7   7     4
8   8     0
9   9     0
10 10     1
11 11     2
12 12     0
13 13     3
14 14     0
15 15     4
16 16     5
17 17     2
18 18     3
19 19     0
20 20     6

I would like to create 4 bins out of df and count the occurrences of Value=0 grouped by Sl values in a separate data frame like below:

Bin Count
1   1
2   2
3   2
4   1

I was trying to use table and cut to create the desire data frame but its not clear how I'll specify df$Value and the logic to find the 0s here

df.4.cut <- as.data.frame(table(cut(df$Sl, breaks=seq(1,20, by=5))))

Answer 1

Using your df

tapply(df$Value, cut(df$Sl, 4), function(x) sum(x==0))

gives

> tapply(df$Value, cut(df$Sl, 4), function(x) sum(x==0))
(0.981,5.75]  (5.75,10.5]  (10.5,15.2]    (15.2,20] 
           1            2            2            1 

In cut you can specify the number of breaks or the breaks itself if you prefer and the logic is in the function definition in tapply