rcountifgroup

Countif in R programming

i have a data frame with the following columns

Vendor Product Price
101 1001 1.50
101 1001 1.50
101 1001 1.80
102 1001 2.10
102 1001 2.10
101 1002 10.10
101 1002 10.10
101 1002 10.10
103 1002 10.10
104 1002 20.10
104 1002 20.10
104 1002 10.10

i need to count how many times each price shows up for each product by each vendor and create a new dataframe df2 like the following:

Product Vendor Price count of Price
1001 101 1.5 2
1001 101 1.8 1
1001 102 2.1 2
1002 101 10.10 3
1002 103 10.10 1
1002 104 10.10 1
1002 104 20.10 2

i am new in R programming and everything i tried so far is not working. Any help would be greatly appreciated

Solution

  • Generating fake data:

    vendor <- sample(x = 1:5,size = 100,replace = TRUE)+100  
product <- sample(x = 1:8,size = 100,replace = TRUE)+1000  
price <- (product-1000) + sample(x = -8:8,size = 100,replace = TRUE)/10  
df <- data.frame(vendor,product,price)

    Solution with dplyr :

    library(dplyr)  
df %>% group_by(vendor,product,price) %>% count %>% ungroup

    Result :

    # A tibble: 88 x 4
   vendor product price     n
    <dbl>   <dbl> <dbl> <int>
 1    101    1001   0.4     1
 2    101    1001   0.8     1
 3    101    1001   1       1
 4    101    1001   1.5     1
 5    101    1001   1.7     2
 6    101    1002   1.2     1
 7    101    1002   1.4     2
 8    101    1004   3.5     1
 9    101    1004   3.8     1
10    101    1004   3.9     2