fayfay
fayfay

Reputation: 23

spread() in define column

Basically for each id i have a set of product id, and i tried to spread them across a set of define columns. each id can only have 5 product_id. ex:

id product_id 
1   305
1   402
2   200
1   305
3   402
3   402

so I spread as a binary outcome like:

id 305 402 200 
1   2   0   0
2   0   0   1
3   0   2   0

but i would like:

id  product1  product2 product3 product4... until 5 
1      305      305       0
2      200      0         0
3      402      402       0

if someone have something clean ( I have around 10K rows) That would be awesome!! thanks!

#this gives me the binary outcome
for (i in names(test2[2:18])) {
  test2$product1[test2[i] == 1 ] <- i
  }

#this is a try to iterate through each row but it s pretty bad

    for(i in 1:nrow(test2)){
  if(test2[i,1]== 1){

    test2$product1[i] <- colnames(test2[1])
  } else if(test2[i,1]==2){

    test2$product1[i] <- colnames(test2[1])
    test2$product2[i] <- colnames(test2[1])
  } else if(test2[i,1]==3){

    test2$product1[i] <- colnames(test2[1])
    test2$product2[i] <- colnames(test2[1])
    test2$product3[i] <- colnames(test2[1])
  } else if(test2[i,1]==4){

and so one...

expected:

id  product1  product2 product3 product4... until 5 
1      305      305       0
2      200      0         0
3      402      402       0

actual:

id 305 402 200 
1   2   0   0
2   0   0   1
3   0   2   0

Upvotes: 2

Views: 41

Answers (1)

akrun
akrun

Reputation: 887511

We could create a sequence column by 'id' and then spread. Note that simply spreading will not have all the 'product' until 5 as these are missing in the data. Inorder to do that, create the sequence as a factor with levels specified from 'product1' to 'product5' and in the spread, specify the drop = FALSE for not dropping the unused levels

library(tidyverse)
df1 %>% 
   group_by(id) %>%
   mutate(product = factor(paste0('product', row_number()), 
             levels = paste0('product', 1:5))) %>% 
   spread(product, product_id, drop = FALSE, fill = 0)
# A tibble: 3 x 6
# Groups:   id [3]
#     id product1 product2 product3 product4 product5    
#  <int>    <dbl>    <dbl>    <dbl>    <dbl>    <dbl>
#1     1      305      402      305        0        0
#2     2      200        0        0        0        0
#3     3      402      402        0        0        0

data

df1 <- structure(list(id = c(1L, 1L, 2L, 1L, 3L, 3L), product_id = c(305L, 
 402L, 200L, 305L, 402L, 402L)), class = "data.frame", row.names = c(NA, 
 -6L))

Upvotes: 1

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