R help - Dec 2012 - splitting a long dataframe

Dear all...Merry Christmas

I would like to split a long dataframe. The dataframe looks like this

x<-c('0:00:00', '0:30:00', '1:00:00',
'1:30:00', '2:00:00', '2:30:00',
'3:00:00', '0:00:00', '0:30:00', '1:00:00',
'1:30:00', '2:00:00',
'2:30:00', '3:00:00', '3:30:00',
'4:00:00','0:00:00', '0:30:00',
'1:00:00', '1:30:00', '2:00:00', '2:30:00',
'3:00:00', '0:00:00',
'0:30:00', '1:00:00', '1:30:00', '2:00:00',
'2:30:00', '3:00:00' ,
'3:30:00', '4:00:00')

y=seq(1:32)

data1=data.frame(x,y)

i want to split in such a way that the output looks like

0:00:00  1  8 17 24
0:30:00  2  9 18 25
1:00:00  3 10 19 26
1:30:00  4 11 20 27
2:00:00  5 12 21 28
2:30:00  6 13 22 29
3:00:00  7 14 23 30
3:30:00 NA 15 NA 31
4:00:00 NA 16 NA 32

any ideas or functions that i look into for doing this?
Thanks a lot for your help and time.

Cheers,
Swagath

Hi,
You can do this either by:
with(data1,aggregate(y,by=list(x),function(x) x)) #2nd column is a list here
#or
?res1<-split(seq(nrow(data1)),data1$x)
#or
res1<-tapply(data1$y,list(data1$x),function(x) x)
res2<- t(sapply(res1,`[`,1:max(sapply(res1,length))))
res2[cbind(c(rep(8,4),rep(9,4)),c(1:4,1:4))]<-res2[cbind(c(rep(8,4),rep(9,4)),c(3,1,4,2,3,1,4,2))]
?res2
#??????? [,1] [,2] [,3] [,4]
#0:00:00??? 1??? 8?? 17?? 24
#0:30:00??? 2??? 9?? 18?? 25
#1:00:00??? 3?? 10?? 19?? 26
#1:30:00??? 4?? 11?? 20?? 27
#2:00:00??? 5?? 12?? 21?? 28
#2:30:00??? 6?? 13?? 22?? 29
#3:00:00??? 7?? 14?? 23?? 30
#3:30:00?? NA?? 15?? NA?? 31
#4:00:00?? NA?? 16?? NA?? 32

#or
res3<-do.call(rbind,lapply(res1,function(x) {if(length(x) < 4)
c(NA,x[1],NA,x[2]) else x}))
?tail(res3)
?# ????? [,1] [,2] [,3] [,4]
#1:30:00??? 4?? 11?? 20?? 27
#2:00:00??? 5?? 12?? 21?? 28
#2:30:00??? 6?? 13?? 22?? 29
#3:00:00??? 7?? 14?? 23?? 30
#3:30:00?? NA?? 15?? NA?? 31
#4:00:00?? NA?? 16?? NA?? 32

identical(res2,res3)
#[1] TRUE

A.K.




----- Original Message -----
From: Swagath <swagathnavin82 at gmail.com>
To: r-help at r-project.org
Cc: 
Sent: Tuesday, December 25, 2012 12:52 PM
Subject: [R] splitting a long dataframe

Dear all...Merry Christmas

I would like to split a long dataframe. The dataframe looks like this

x<-c('0:00:00', '0:30:00', '1:00:00',
'1:30:00', '2:00:00', '2:30:00', '3:00:00',
'0:00:00', '0:30:00', '1:00:00', '1:30:00',
'2:00:00', '2:30:00', '3:00:00', '3:30:00',
'4:00:00','0:00:00', '0:30:00', '1:00:00',
'1:30:00', '2:00:00', '2:30:00', '3:00:00',
'0:00:00', '0:30:00', '1:00:00', '1:30:00',
'2:00:00', '2:30:00', '3:00:00' , '3:30:00',
'4:00:00')

y=seq(1:32)

data1=data.frame(x,y)

i want to split in such a way that the output looks like

0:00:00? 1? 8 17 24
0:30:00? 2? 9 18 25
1:00:00? 3 10 19 26
1:30:00? 4 11 20 27
2:00:00? 5 12 21 28
2:30:00? 6 13 22 29
3:00:00? 7 14 23 30
3:30:00 NA 15 NA 31
4:00:00 NA 16 NA 32

any ideas or functions that i look into for doing this?
Thanks a lot for your help and time.

Cheers,
Swagath

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On Dec 25, 2012, at 9:52 AM, Swagath wrote:
> Dear all...Merry Christmas
>
> I would like to split a long dataframe. The dataframe looks like this
>
> x<-c('0:00:00', '0:30:00', '1:00:00',
'1:30:00', '2:00:00',
> '2:30:00', '3:00:00', '0:00:00', '0:30:00',
'1:00:00', '1:30:00',
> '2:00:00', '2:30:00', '3:00:00', '3:30:00',
'4:00:00','0:00:00',
> '0:30:00', '1:00:00', '1:30:00', '2:00:00',
'2:30:00', '3:00:00',
> '0:00:00', '0:30:00', '1:00:00', '1:30:00',
'2:00:00', '2:30:00',
> '3:00:00' , '3:30:00', '4:00:00')
>
> y=seq(1:32)
>
> data1=data.frame(x,y)
>
> i want to split in such a way that the output looks like
>
> 0:00:00  1  8 17 24
> 0:30:00  2  9 18 25
> 1:00:00  3 10 19 26
> 1:30:00  4 11 20 27
> 2:00:00  5 12 21 28
> 2:30:00  6 13 22 29
> 3:00:00  7 14 23 30
> 3:30:00 NA 15 NA 31
> 4:00:00 NA 16 NA 32
>
> any ideas or functions that i look into for doing this?
You already have 3 distinct solutions on StackOverflow.
>

David Winsemius, MD
Alameda, CA, USA