On 30/08/2007, at 9:41 AM, tkobayas at indiana.edu wrote:
> Rusers,
>
> I am trying to append multiple .csv files of different dimensions (but
> # of columns are the same for all .csv files). I do have .csv files
> whose names are CA1.csv ~ CA100.csv. CA means california and 1 means
> the first file. So what I have been doing (after googling how to
> append
> by row multiple files) was:
>
> cleanup_data<-function(state,count)
> {
> out<-matrix()
> for (i in 1: count)
> {
> tmp<-read.csv(paste
> ("CTPP3/",state,i,".csv",sep=""),header=F)
> out<-rbind(out,tmp)
> }
> write.csv(file.out,file='file_output.csv')
> }
>
> I got an error message:
>
> cleanup_data('CA',7)
> Error in match.names(clabs, names(xi)) : names do not match
> previous names
>
>
> Which name is this error message referring to?
>
> I decided to get out of Excel and Access trap.....
Good thinking!
I'd guess that the problem is with the initialization of ``out''.
This matrix doesn't
have *any* column names, whereas the data frame (***not*** matrix!)
``tmp''
will have column names V1, V2, .... (or something like that).
You could solve your problem by initializing
out <- NULL
(instead of matrix()).
Your ``write.csv'' at the end will throw an error if the function
ever gets to it ----
``file.out'' doesn't exist. You perhaps want write.csv(out,
file="etc.").
This is not good programming anyhow --- your cleanup_data() function
should
*return a value*. The write.csv call should be ``done to this
value'', outside of
the cleanup_data() function. IMHO.
A sexier way to do what you want would be:
cleanup_data <- function(state,count) {
rslt <- list()
for(i in 1:count) rslt[[i]] <- read.csv(paste("etc."))
do.call(rbind,rslt)
}
cheers,
Rolf Turner
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