CODEWITHSUNDEEP
raggregatereshape
jeroen81
jeroen81

Reputation: 2425

Reshaping data frame to create list of unique values in column

I have the data set:

df <- data.frame(g = c("X", "X", "Y", "Z", "Y", "Z", "Z"),
                 r = c("A", "B", "C", "C", "A", "A", "A"))

And I would to manipulate the data in a way that I get the result:

g | r
X | A B
Y | A C
Z | A C

So for each g all the unique r values are listed. I can use the reshape package for this. But I would like to be able to do this with standard R, because the script will be shared with people with a very limited knowledge of R.

Upvotes: 3

Views: 596

Answers (2)

Simon O&#39;Hanlon
Simon O&#39;Hanlon

Reputation: 60000

How about aggregate()?

aggregate( df$r , by = list( df$g ) , function(x) paste0( sort( unique(x) ) , collapse = "" ) )
#  Group.1  x
#1       X AB
#2       Y AC
#3       Z AC

Upvotes: 2

datawookie
datawookie

Reputation: 6584

Give this a try:

dg <- data.frame(
  g = levels(df$g),
  r = tapply(df$r, df$g, function(n) {paste(sort(unique(n)), collapse = " ")})
  )
> dg
  g   r
X X A B
Y Y A C
Z Z A C

Upvotes: 1

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