CODEWITHSUNDEEP
rreplaceconditional-statements
Naveen Suman
Naveen Suman

Reputation: 147

Update column values randomly based on value in other column in R

I want to add a new column SubCategory with values filled randomly based on value of Category column. Here's the details:

Sub_Hair = c("Shampoo", "Conditioner", "Gel", "HairOil", "Dye")
Sub_Beauty = c("Face", "Eye", "Lips")
Sub_Nail= c("NailPolish", "NailPolishRemover", "NailArtKit", "ManiPadiKit")
Sub_Others = c("Electric", "NonElectric")

> product_data_1[1:10, c("Pcode", "Category", "MRP")]
    Pcode Category    MRP
1  16156L   Beauty  $8.88
2  16162M   Others $21.27
3  16168M   Others  $2.98
4  16169E     Nail $26.64
5  16207A     Hair  $6.38
6  17012B   Beauty $33.03
7  17012C   Beauty $20.58
8  17012F   Beauty $36.29
9  17091A     Nail $20.55
10 17107D     Nail $28.20

I'm trying the below code. However, the rows are getting updated with just one subcategory for each category. For example, all rows with "Beauty" category, the subcategory is "Eye" instead of values randomly selected from "Face, Eye and Lips". Here's the code and output:

product_data_1 = within(product_data_1, SubCategory[Category == "Beauty"] <- sample(Sub_Beauty, 1))
product_data_1 = within(product_data_1, SubCategory[Category == "Hair"] <- sample(Sub_Hair, 1))
product_data_1 = within(product_data_1, SubCategory[Category == "Nail"] <- sample(Sub_Nail, 1))
product_data_1 = within(product_data_1, SubCategory[Category == "Others"] <- sample(Sub_Others, 1))

> product_data_1[1:10, c("Pcode", "Category", "MRP", "SubCategory")]
    Pcode Category    MRP SubCategory
1  16156L   Beauty  $8.88         Eye
2  16162M   Others $21.27    Electric
3  16168M   Others  $2.98    Electric
4  16169E     Nail $26.64  NailPolish
5  16207A     Hair  $6.38         Gel
6  17012B   Beauty $33.03         Eye
7  17012C   Beauty $20.58         Eye
8  17012F   Beauty $36.29         Eye
9  17091A     Nail $20.55  NailPolish
10 17107D     Nail $28.20  NailPolish

Upvotes: 0

Views: 50

Answers (2)

user10191355
user10191355

Reputation:

Put your subcategory values in a list like subcat_list <- list(Hair = Hair, Beauty = Beauty, Nail = Nail, Others = Others). You can then use product_data_1$Category to slice subcat_list and sapply to call sample on each element of the resultant list of vectors:

set.seed(323)
product_data_1$SubCategory <- sapply(subcat_list[product_data_1$Category], sample, 1)

You can also try a slightly different approach with dplyr + purrr:

library(tidyverse)
product_data_1 %>% 
    mutate(SubCategory = map_chr(Category, ~ sample(subcat_list[[.]], 1)))

Example output:

    Pcode Category    MRP SubCategory
1  16156L   Beauty  $8.88         Eye
2  16162M   Others $21.27    Electric
3  16168M   Others  $2.98    Electric
4  16169E     Nail $26.64  NailPolish
5  16207A     Hair  $6.38         Gel
6  17012B   Beauty $33.03         Eye
7  17012C   Beauty $20.58        Lips
8  17012F   Beauty $36.29        Face
9  17091A     Nail $20.55 ManiPadiKit
10 17107D     Nail $28.20  NailArtKit

Upvotes: 1

Rui Barradas
Rui Barradas

Reputation: 76460

Here is a base R solution. It uses the split/apply/combine strategy explained in this JSS article by Hadley Wickham.

I will put the Sub_* vectors in a list, Sub_list. Be careful, split will order the result by Category so the list Sub_list must also have the vectors in order.

Sub_list <- list(Sub_Beauty, Sub_Hair, Sub_Nail, Sub_Others)
sp <- split(product_data_1, product_data_1$Category)

set.seed(1234)
sp <- lapply(seq_along(sp), function(i){
  sp[[i]]$SubCategory <- sample(Sub_list[[i]], nrow(sp[[i]]), replace = TRUE)
  sp[[i]]
})
result <- do.call(rbind, sp)
result <- result[order(as.integer(row.names(result))), ]
result
#    Pcode Category    MRP       SubCategory
#1  16156L   Beauty  $8.88               Eye
#2  16162M   Others $21.27       NonElectric
#3  16168M   Others  $2.98       NonElectric
#4  16169E     Nail $26.64        NailPolish
#5  16207A     Hair  $6.38           Shampoo
#6  17012B   Beauty $33.03               Eye
#7  17012C   Beauty $20.58              Face
#8  17012F   Beauty $36.29              Lips
#9  17091A     Nail $20.55 NailPolishRemover
#10 17107D     Nail $28.20       ManiPadiKit

Final clean up.

rm(Sub_list)

Data 

product_data_1 <- read.table(text = "
    Pcode Category    MRP
1  16156L   Beauty  $8.88
2  16162M   Others $21.27
3  16168M   Others  $2.98
4  16169E     Nail $26.64
5  16207A     Hair  $6.38
6  17012B   Beauty $33.03
7  17012C   Beauty $20.58
8  17012F   Beauty $36.29
9  17091A     Nail $20.55
10 17107D     Nail $28.20
", header = TRUE)

Upvotes: 1

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