thr3ads.net - R help - [R] Simple but elusive - expand back from counts [Mar 2011]

If this information is useful, please help other people find it:
Share via:

jjap

2011-Mar-29 18:15 UTC

[R] Simple but elusive - expand back from counts

Dear R-users,

This should be simple but still eludes me:

Given the following
tmp<-as.data.frame(matrix(c(44, 10, "abc", 1, 44, 10,
"def", 1, 44, 12,
"abc", 2), 3, 4, byrow=T))

I want to  expand the data to the following form:

  V1 V2  V3 V4
1 44 10 abc  1
2 44 10 def  1
3 44 12 abc  1
4 44 12 abc  1

The last row of the original df was duplicated the row by the number in the
4th column (which could be expendable being all ones)
I clumsily tried a few variants of a loop but I am not making any progress.
Any hints would be greatly appreciated.
for (i in 1:3){
  rbind(rep(tmp[i,], temp[i,4])
  }

--
View this message in context:
http://r.789695.n4.nabble.com/Simple-but-elusive-expand-back-from-counts-tp3415727p3415727.html
Sent from the R help mailing list archive at Nabble.com.

Joshua Wiley

2011-Mar-29 19:16 UTC

head link

[R] Simple but elusive - expand back from counts

Hi,

You can use rep() to repeat the appropriate rows as in V4.  For example:

tmp[rep(rownames(tmp), tmp$V4), ]

    V1 V2  V3 V4
1   44 10 abc  1
2   44 10 def  1
3   44 12 abc  2
3.1 44 12 abc  2

if you wanted, you could then reset the row names to NULL to get 1, 2,
3, 4 rather than 3, 3.1

rownames(tmp) <- NULL ## AFTER saving the expanded form.

Cheers,

Josh

On Tue, Mar 29, 2011 at 11:15 AM, jjap <sabjap at gmail.com>
wrote:> Dear R-users,
>
> This should be simple but still eludes me:
>
> Given the following
> tmp<-as.data.frame(matrix(c(44, 10, "abc", 1, 44, 10,
"def", 1, 44, 12,
> "abc", 2), 3, 4, byrow=T))
>
> I want to ?expand the data to the following form:
>
> ?V1 V2 ?V3 V4
> 1 44 10 abc ?1
> 2 44 10 def ?1
> 3 44 12 abc ?1
> 4 44 12 abc ?1
>
> The last row of the original df was duplicated the row by the number in the
> 4th column (which could be expendable being all ones)
> I clumsily tried a few variants of a loop but I am not making any progress.
> Any hints would be greatly appreciated.
> for (i in 1:3){
> ?rbind(rep(tmp[i,], temp[i,4])
> ?}
>
> --
> View this message in context:
http://r.789695.n4.nabble.com/Simple-but-elusive-expand-back-from-counts-tp3415727p3415727.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>


-- 
Joshua Wiley
Ph.D. Student, Health Psychology
University of California, Los Angeles
http://www.joshuawiley.com/

Peter Alspach

2011-Mar-29 19:17 UTC

head link

[R] Simple but elusive - expand back from counts

Tena koe

Try something like:

tmp[rep(1:nrow(tmp), each=tmp[,4]),] # untested

HTH ...

Peter Alspach
> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of jjap
> Sent: Wednesday, 30 March 2011 7:16 a.m.
> To: r-help at r-project.org
> Subject: [R] Simple but elusive - expand back from counts
> 
> Dear R-users,
> 
> This should be simple but still eludes me:
> 
> Given the following
> tmp<-as.data.frame(matrix(c(44, 10, "abc", 1, 44, 10,
"def", 1, 44, 12,
> "abc", 2), 3, 4, byrow=T))
> 
> I want to  expand the data to the following form:
> 
>   V1 V2  V3 V4
> 1 44 10 abc  1
> 2 44 10 def  1
> 3 44 12 abc  1
> 4 44 12 abc  1
> 
> The last row of the original df was duplicated the row by the number in
> the
> 4th column (which could be expendable being all ones)
> I clumsily tried a few variants of a loop but I am not making any
> progress.
> Any hints would be greatly appreciated.
> for (i in 1:3){
>   rbind(rep(tmp[i,], temp[i,4])
>   }
> 
> --
> View this message in context: http://r.789695.n4.nabble.com/Simple-but-
> elusive-expand-back-from-counts-tp3415727p3415727.html
> Sent from the R help mailing list archive at Nabble.com.
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-
> guide.html
> and provide commented, minimal, self-contained, reproducible code.
The contents of this e-mail are confidential and may be subject to legal
privilege.
 If you are not the intended recipient you must not use, disseminate, distribute
or
 reproduce all or any part of this e-mail or attachments.  If you have received
this
 e-mail in error, please notify the sender and delete all material pertaining to
this
 e-mail.  Any opinion or views expressed in this e-mail are those of the
individual
 sender and may not represent those of The New Zealand Institute for Plant and
 Food Research Limited.

Petr Savicky

2011-Mar-29 19:18 UTC

head link

[R] Simple but elusive - expand back from counts

On Tue, Mar 29, 2011 at 11:15:33AM -0700, jjap wrote:> Dear R-users,
> 
> This should be simple but still eludes me:
> 
> Given the following
> tmp<-as.data.frame(matrix(c(44, 10, "abc", 1, 44, 10,
"def", 1, 44, 12,
> "abc", 2), 3, 4, byrow=T))
> 
> I want to  expand the data to the following form:
> 
>   V1 V2  V3 V4
> 1 44 10 abc  1
> 2 44 10 def  1
> 3 44 12 abc  1
> 4 44 12 abc  1
> 
> The last row of the original df was duplicated the row by the number in the
> 4th column (which could be expendable being all ones)
Hi.

Try the following.

  tmp1 <- tmp[rep(1:nrow(tmp), times=tmp$V4), ]
  tmp1$V4 <- 1
  row.names(tmp1) <- NULL
  tmp1

    V1 V2  V3 V4
  1 44 10 abc  1
  2 44 10 def  1
  3 44 12 abc  1
  4 44 12 abc  1

Hope this helps.

Petr Savicky.

Henrique Dallazuanna

2011-Mar-29 19:19 UTC

head link

[R] Simple but elusive - expand back from counts

Try this:

transform(tmp[rep(seq(nrow(tmp)), as.numeric(tmp$V4)),], V4 = 1)

On Tue, Mar 29, 2011 at 3:15 PM, jjap <sabjap at gmail.com>
wrote:> Dear R-users,
>
> This should be simple but still eludes me:
>
> Given the following
> tmp<-as.data.frame(matrix(c(44, 10, "abc", 1, 44, 10,
"def", 1, 44, 12,
> "abc", 2), 3, 4, byrow=T))
>
> I want to ?expand the data to the following form:
>
> ?V1 V2 ?V3 V4
> 1 44 10 abc ?1
> 2 44 10 def ?1
> 3 44 12 abc ?1
> 4 44 12 abc ?1
>
> The last row of the original df was duplicated the row by the number in the
> 4th column (which could be expendable being all ones)
> I clumsily tried a few variants of a loop but I am not making any progress.
> Any hints would be greatly appreciated.
> for (i in 1:3){
> ?rbind(rep(tmp[i,], temp[i,4])
> ?}
>
> --
> View this message in context:
http://r.789695.n4.nabble.com/Simple-but-elusive-expand-back-from-counts-tp3415727p3415727.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>


-- 
Henrique Dallazuanna
Curitiba-Paran?-Brasil
25? 25' 40" S 49? 16' 22" O

Maybe Matching Threads

Search for more seemingly similar threads

R help - Mar 2011 - Simple but elusive - expand back from counts

[R] Simple but elusive - expand back from counts

[R] Simple but elusive - expand back from counts

[R] Simple but elusive - expand back from counts

[R] Simple but elusive - expand back from counts

[R] Simple but elusive - expand back from counts

Maybe Matching Threads