Thanks Jeff. I had tried the 'list' approach as well but got stuck with the
below error:
"Error in `$<-.data.frame`(`*tmp*`, "date", value = "20100701") :
replacement has 1 rows, data has 0"
Couldnt find a work around to this, hence resorted to the multiple
dataframes approach. Any insights int
Programatically dealing with large numbers of separately-named objects leads to
syntactically complicated code that is hard to read and maintain.
Load the data frames into a list so you can access them by numeric or named
index, and then getting at the loaded data will be much easier.
fnames =
Reposting in hope of a reply.
On Tue, Apr 24, 2012 at 1:12 AM, Shivam wrote:
> Thanks for the quick response. It works for an individual dataframe, but I
> have many dataframes. This is the code so far
>
> fnames = list.files(path = getwd())
> for (i in 1:length(fnames)){
> assign(paste("file",i
Thanks for the quick response. It works for an individual dataframe, but I
have many dataframes. This is the code so far
fnames = list.files(path = getwd())
for (i in 1:length(fnames)){
assign(paste("file",i,sep=""),read.csv.sql(fnames[i], sql = "select * from
file where V3 == 'XXX' and V5=='YYY'"
This little example might help.
> foo <- data.frame(a=1:10, b=letters[1:0])
> foo
a b
1 1 a
2 2 a
3 3 a
4 4 a
5 5 a
6 6 a
7 7 a
8 8 a
9 9 a
10 10 a
> foo$date <- '20120423'
> foo
a b date
1 1 a 20120423
2 2 a 20120423
3 3 a 20120423
4 4 a 20120423
5 5 a 2012
This might do it for you:
for (i in fileNames){
input <- read.table(i, .)
# you might want to use regular expressions to extract just the date.
input$fileName <- i
write.table(i, )
}
On Mon, Apr 23, 2012 at 12:29 PM, Shivam wrote:
> Hi,
>
> I am relatively new to R. Have
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