df aggregate and list factors if one column is unique

Question

I got the following df and a bit stuck at the moment:

df1
X1    X2    X3    X4
A     1     a     x
A     2     a     x
A     3     a     y
B     1     b     x
...

and I am trying to aggregate the df so that I have a unique value IF X4 is the same so I want this:

df2
X1    X2    X3    X4
A     1,2   a     x
A     3     a     y
B     1     b     x
...

I tried this:

df2 <-aggregate(.~X1,df1,unique)

but it doesn't really work. X2 is also a numerical value, but I want it listed as if it were a character (transformed it into character).

Can someone help?

You may need `aggregate(.~ X1, df1, function(x) toString(unique(x)))` — akrun, Jan 21 '20 at 21:55
Or `aggregate(.~ X1 + X3 + X4, df1, function(x) toString(unique(x)))` — Maurits Evers, Jan 21 '20 at 21:57
thank you that already solved the problem with the numerical value! But is there a way to assure that its only aggregated according to X1 IF X4 is all the same? — antonina, Jan 21 '20 at 21:59
okay it worked with `aggregate(.~ X1+X4, df1, function(x) toString(unique(x)))` — antonina, Jan 21 '20 at 22:01

score 0 · Answer 1 · answered Jan 21 '20 at 22:06

0

We can paste the unique elements

aggregate(.~ X1, df1, function(x) toString(unique(x)))

answered Jan 21 '20 at 22:06

akrun

1 Answers1