processing data frame in R

Question

I have this data frame. I would like to put each unique Dept and place the corresponding Name under each unique Dept. As you can see there are multiple Dept. For example, final dcoument should look like this:

Internet
    Public-Web
    Intranet
BackOffice
    Batch
    BackEnd
BackEnd
   WebLogic
   Oracle

dput(x)

structure(list(ID = c(1234L, 2345L, 6789L, 3456L, 7890L, 1987L
), Name = structure(c(5L, 3L, 2L, 1L, 6L, 4L), .Label = c("BackEnd", 
"Batch", "Intranet", "Oracle", "Public-Web", "WebLogic"), class = "factor"), 
    Dept = structure(c(3L, 3L, 2L, 2L, 1L, 1L), .Label = c("BackEnd", 
    "BackOffice", "Internet"), class = "factor")), .Names = c("ID", 
"Name", "Dept"), class = "data.frame", row.names = c(NA, -6L))

Any ideas how I would do this in R?

Arun · Answer 1 · 2013-03-28T21:20:40.647

1

You can use split to achieve this:

split(as.character(df$Name), df$Dept)

# $BackEnd
# [1] "WebLogic" "Oracle"  
# 
# $BackOffice
# [1] "Batch"   "BackEnd"
# 
# $Internet
# [1] "Public-Web" "Intranet"

If you want unique entries, then just do:

df <- unique(df[, 2:3])
split(as.character(df$Name), df$Dept)

edited Mar 28 '13 at 21:20

answered Mar 28 '13 at 19:49

Arun

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I need to use a two for loops. For each unique Dept, I need to list out the Name. I will be doing more processing under Name in the second loop. – user1471980 Mar 28 '13 at 19:57
1

I don't understand your comment. Arun answer is much faster than the two loops. – Manoel Galdino Mar 28 '13 at 21:11
I guess he just doesn't know how to iterate after the `split` – Julián Urbano Mar 28 '13 at 21:25
you mean he's not interested in "storing" this in a variable, rather just printing? – Arun Mar 28 '13 at 21:28
something like that, yes. My guess, anyway – Julián Urbano Mar 28 '13 at 21:37

score 1 · Accepted Answer · answered Mar 28 '13 at 20:14

I'll assume you may have duplicates, and therefore use unique:

for(dept in unique(x$Dept)){
  print(dept)
  x2 <- subset(x,subset=Dept==dept)
  for(name in unique(x2$Name)){
    print(paste(sep="","  ",name))
  }
}

Replace the print whith whatever you need.

processing data frame in R

2 Answers2