[R] comparing columns in a dataframe

[baptiste auguie]

Hi,

Have you looked at the compare package? It might do what you want (I  
just remember seeing its description on R News recently but I've never  
used it),

> d <- data.frame(x=1:10,y=sin(1:10),z=factor(letters[1:10]))
> d1 <- d
> d1$x[2:3] <- jitter(d$x[2:3] )
> d2 <- subset(d1, !(z %in% c("a","g")))
>
> compare(d,d2,allowAll=T)->test
> str(test)

Just an idea,


baptiste



On 4 Apr 2009, at 23:45, markleeds at verizon.net wrote:

>
>   Hi: you've got to create a setdiff in both directions in order to  
> get the
>   lone ones in each column because setdiff is
>   not commutative meaning that setdiff(a,b) does not equal  
> setdiff(b,a). once
>   you do that, then
>   ( setdiff1 + setdiff2 - intersect ) should equal the union.
>   if it doesn't, that would be weird and more investigation would  
> need to be
>   done.
>
>   On Apr 4, 2009, Bob Green <bgreen at dyson.brisnet.org.au> wrote:
>
>     hello,
>     I am hoping for some advice regarding comparing variables from 3
>     versions of a spreadsheet which have been combined into a single
>     dataframe. The aim is to identify which rows have been changed.
>     The dataframe contains 177 rows of data (each cell contains text).
>     'intersect' produced a file with 35 rows, 'union' a file with 303
>     rows and 'setdiff' a file with 130 rows
>     Below is the code that I have started with.
>     Ideally I would like to identify the actual row numbers where  
> there
>     is difference in the variables (either pairwise or between 3  
> variables).
>     x <- read.csv("c://rec_compare.csv",header=T, as.is=TRUE)
>     u <- union(x$rm1, x$redc1)
>     write.csv(u,"c:/union_test.csv")
>     i <- intersect(x$rm1, x$redc1)
>     write.csv(i,"c:/intersect_test.csv")
>     sd <- setdiff(x$rm1, x$redc1)
>     write.csv(sd,"c:/setdiff_test.csv")
>     Any suggestions are appreciated.
>     regards
>     Bob
>     ______________________________________________
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>
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_____________________________

Baptiste Auguié

School of Physics
University of Exeter
Stocker Road,
Exeter, Devon,
EX4 4QL, UK

Phone: +44 1392 264187

http://newton.ex.ac.uk/research/emag