hi Erin,
Thanks for your reply to my problems. I tried and it works, but it sorted
all the column. In my case, I want it to sort d user_id column and  another
information in other column will follow it. Now, after I sorted, the
information which website viewed by user was wrong. I want to as how we can
sort or filter in excel.

Thank you.

regards,
hema

On Fri, Apr 3, 2009 at 4:44 PM, Umesh Srinivasan <umesh.srinivasan@gmail.com
> wrote:

> Hi,
> There is definitely a more elegant way of doing this which I don't know
> about (without a for loop), but try this:
>
> mat <- matrix(NA, nrow = max(user_id), ncol = 2)
> mat[,1] <- 1:max(user_id) # 1st column of matrix is the user ID
>
> for (i in 1:max(user_id)){
> temp1 <- subset(data, user_id = i)
> temp2 <- unique(temp1$website)
> mat[2,i] <- length(temp2)
> }
>
> The matrix will give you user id and number of sites visited, provided user
> id ranges from 1 to the number of users. There must be a way to do this
> using table, but I cant figure it out.
>
> Cheers,
> Umesh
>
> On Fri, Apr 3, 2009 at 1:42 PM, Dieter Menne
> <dieter.menne@menne-biomed.de>wrote:
>
> >
> >
> >
> > Hem wrote:
> > >
> > > user_id  website          time
> > > 20        google            0930
> > > 21        yahoo            0935
> > > 20        facebook        1000
> > > 25        facebook        1015
> > > 61        google            0940
> > > ...
> > > My problem is how to sort the data? So that, I can get information
> about
> > > one
> > > user_id viewed how many website perday?
> > >
> > >
> >
> > Maybe you were looking at the wrong item, because what you want is not
> > sorting, but a table.
> >
> > Check the documentation of table or ftable.
> >
> > Dieter
> >
> > --
> > View this message in context:
> >
> http://www.nabble.com/how-to-sort-and-plot-data--tp22861661p22863918.html
> > Sent from the R help mailing list archive at Nabble.com.
> >
> > ______________________________________________
> > R-help@r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide
> > http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
> >
>
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>
> ______________________________________________
> R-help@r-project.org mailing list
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> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
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>

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