Re: [R] Using indexing to manipulate data

2010-03-18 Thread William Dunlap
> -Original Message- > From: r-help-boun...@r-project.org > [mailto:r-help-boun...@r-project.org] On Behalf Of Jim Lemon > Sent: Thursday, March 18, 2010 1:33 AM > To: duncandonutz > Cc: r-help@r-project.org > Subject: Re: [R] Using indexing to manipulate data >

Re: [R] Using indexing to manipulate data

2010-03-18 Thread Gabor Grothendieck
Here are two solutions. The first uses merge and the second uses sqldf. They both do a self join picking off the unique pairs. The sqldf solution also sorts the result: # input DF <- structure(list(Actor = c("Jim", "Bob", "Bob", "Larry", "Alice", "Tom", "Tom", "Tom", "Alice", "Nancy"), Act = c(

Re: [R] Using indexing to manipulate data

2010-03-18 Thread Dimitris Rizopoulos
One approach is the following: Dat <- read.table(textConnection( "Jim A BobA BobC Larry D Alice C Tom F Tom D Tom A Alice B NancyB")) closeAllConnections() names(Dat) <- c("name", "act") out <- tapply(as.character(Dat$name), Dat$act,

Re: [R] Using indexing to manipulate data

2010-03-18 Thread Jim Lemon
On 03/18/2010 04:05 PM, duncandonutz wrote: I know one of R's advantages is it's ability to index, eliminating the need for control loops to select relevant data, so I thought this problem would be easy. I can't crack it. I have looked through past postings, but nothing seems to match this pro

[R] Using indexing to manipulate data

2010-03-17 Thread duncandonutz
I know one of R's advantages is it's ability to index, eliminating the need for control loops to select relevant data, so I thought this problem would be easy. I can't crack it. I have looked through past postings, but nothing seems to match this problem I have a data set with one column of act