R help - May 2010 - Is there an easier way to replace the object name in the R code

Hi all,

I have a R code with quite a few lines.  For instance

AA <- read.csv(C:\\AA.txt)
AA.diff <- diff(log(AA))
.....
....

Now I want to re-define the code with different object, like BB,
CC......ZZ(the codes are the same). Thus, I was wondering whether their is
an efficient way or automatic way to replace and generate new objects rather
than using "find and replace" function in txt/word manually....?

Appreciate for any help.

Many thanks
mam

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mam3xs wrote:
> Hi all,
> 
> I have a R code with quite a few lines.  For instance
> 
> AA <- read.csv(C:\\AA.txt)
> AA.diff <- diff(log(AA))
> .....
> ....
> 
> Now I want to re-define the code with different object, like BB,
> CC......ZZ(the codes are the same). Thus, I was wondering whether their is
> an efficient way or automatic way to replace and generate new objects
rather
> than using "find and replace" function in txt/word manually....?
> 
Defining your own functions, using lists, and lapply would work just great most 
likely.

Untested, but something like should work:

#create list of all file names
files <- sapply(LETTERS, function(x) paste(x,x, sep = "", collapse
= ""))

#read in the files into a list.
my.list <- lapply(files, function(x)
    read.csv(paste("C:\\", x, ".txt", sep = ""))

#apply a function to each item in the list
lapply(my.list, function(x) diff(log(x)))