R help - Dec 2013 - Counts of duplicate rows as a new column without grouping of duplicates raws.

Hi everyone,

My data looks like this one:
   A    B     C
1 a     1     ff
2 b     1     re
3 c     1     sd
5 a     2     as
6 c     4     fe
7 d     5      tt
8 d     5      tt
9 d     9      oi

I want to add a new column D, which will contain how many an element from
the column A is repeated, like this:
   A    B     C   D
1 a     1     ff    2
2 b     1     re  1
3 c     1     sd  2
5 a     2     as  2
6 c     4     fe   2
7 d     5     tt   3
8 d     5     tt   3
9 d     9     oi   3

I don't want to simplify my data and grouping raws like in this thread:
https://stat.ethz.ch/pipermail/r-help/2011-March/270481.html

Thanks in advance for any help,
best regards,
Bartek

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Hi,
Try:
dat1 <- read.table(text="A??? B??? C
1 a??? 1??? ff
2 b??? 1??? re
3 c??? 1??? sd
5 a??? 2??? as
6 c??? 4??? fe
7 d??? 5????? tt
8 d??? 5????? tt
9 d??? 9????? oi",sep="",header=TRUE,stringsAsFactors=FALSE)

?within(dat1,D<-ave(seq_along(A),A,FUN=length))
A.K.




On Thursday, December 26, 2013 11:28 AM, Bart?omiej Taciak <bartek.taciak at
gmail.com> wrote:
Hi everyone,

My data looks like this one:
?  A? ? B? ?  C
1 a? ?  1? ?  ff
2 b? ?  1? ?  re
3 c? ?  1? ?  sd
5 a? ?  2? ?  as
6 c? ?  4? ?  fe
7 d? ?  5? ? ? tt
8 d? ?  5? ? ? tt
9 d? ?  9? ? ? oi

I want to add a new column D, which will contain how many an element from
the column A is repeated, like this:
?  A? ? B? ?  C?  D
1 a? ?  1? ?  ff? ? 2
2 b? ?  1? ?  re? 1
3 c? ?  1? ?  sd? 2
5 a? ?  2? ?  as? 2
6 c? ?  4? ?  fe?  2
7 d? ?  5? ?  tt?  3
8 d? ?  5? ?  tt?  3
9 d? ?  9? ?  oi?  3

I don't want to simplify my data and grouping raws like in this thread:
https://stat.ethz.ch/pipermail/r-help/2011-March/270481.html

Thanks in advance for any help,
best regards,
Bartek

??? [[alternative HTML version deleted]]

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