count rows with specific column condition in R

Question

Suppose that I have dataset, created by this code:

set.seed(3192)
Data <- data.frame(
  X = sample(50,20),
  Y = sample(letters[1:4], 20, replace = TRUE)
)
Data <- Data[do.call(order,Data),]
Data
## X  Y 
## 2  b
## 3  c
## 4  c
## ...
## ...
## 47 c
## 49 d
## 50 a

I want to count occurrence of "C" in the column Y, by scanning window size of 10 in column X. So, the output will be look like this:

X_Range Count_of_c
 1-10      2
11-20      0
21-30      4
31-40      1
41-50      1

Is there anyone have an idea?

Answer 1

You can use cut function to create group onyour x column and then group by this cut column to calculate the count (here, I'm using dplyr ):

library(dplyr)
Data %>%  mutate(Cut = cut(X, breaks = seq(0,50, by = 10))) %>% 
  group_by(Cut,Y,.drop = FALSE) %>%
  summarise(Count_of_c = n()) %>%
  filter(Y =="c") 

# A tibble: 5 x 3
# Groups:   Cut [5]
  Cut     Y     Count_of_c
  <fct>   <fct>      <int>
1 (0,10]  c              0
2 (10,20] c              0
3 (20,30] c              1
4 (30,40] c              1
5 (40,50] c              3

Does it look what you are expecting?