CODEWITHSUNDEEP
rdataframe
elJorge
elJorge

Reputation: 163

Restructure a dataframe

i've following issue using R for my:

Let's say i've following dataframe:

dates <- c("2010-01-01","2010-02-01","2010-03-01","2010-04-01",
           "2010-02-01","2010-03-01","2010-04-01","2010-05-01",
           "2010-03-01","2010-04-01","2010-05-01","2010-06-01")

data.frame(A=c(1,1,1,1,2,2,2,2,3,3,3,3),B=dates,C=c(21:32))

R delivers for this exmaple-data:

   A          B  C
1  1 2010-01-01 21
2  1 2010-02-01 22
3  1 2010-03-01 23
4  1 2010-04-01 24
5  2 2010-02-01 25
6  2 2010-03-01 26
7  2 2010-04-01 27
8  2 2010-05-01 28
9  3 2010-03-01 29
10 3 2010-04-01 30
11 3 2010-05-01 31
12 3 2010-06-01 32

I need to transform this dateframe in the following structure:

    "2010-01-01"  "2010-02-01"  "2010-03-01"  "2010-04-01"  "2010-05-01"  "2010-06-01"   
1    21            22            23            24            na            na          
2    na            25            26            27            28            na
3    na            na            29            30            30            31

Any suggestions? (I'm new using R and tried to solve it for a couple of hours ;))

Upvotes: 0

Views: 69

Answers (1)

Justin
Justin

Reputation: 43245

you can use the reshape2 package and the dcast function:

library(reshape2)
dcast(dat, A ~ B, value.var='C')

#   A 2010-01-01 2010-02-01 2010-03-01 2010-04-01 2010-05-01 2010-06-01
# 1 1         21         22         23         24         NA         NA
# 2 2         NA         25         26         27         28         NA
# 3 3         NA         NA         29         30         31         32

You can also do this with the base R function reshape, but I find its syntax confusing at best!

Upvotes: 4

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