Hi: Suppose that I have a data frame as below x1 x2 x3 ... x10 wk1 wk2 ... Wk208 (these are the column names) For each record, x1, x2, x3 ... x10 are attributes. and wk1, wk2, ..., wk208 are the sales recoreded for this attribute combination. Suppose that now, that I want to do the following 1. Merge the data frame so that I have a new data frame grouped by values of x2 and x3 (for example). That is, if two records have the same values of x2 and x3, they should be summed. I tried to look at merge, tapply etc. but did not see a fit with I want to do above. Thanks in advance. Satish
Tena koe Satish I'm not entirely sure what you want, but did you check aggregate()? HTH .... Peter Alspach> -----Original Message----- > From: r-help-bounces at r-project.org > [mailto:r-help-bounces at r-project.org] On Behalf Of Vadlamani, > Satish {FLNA} > Sent: Friday, 6 November 2009 10:16 a.m. > To: 'R-help at r-project.org' > Subject: [R] Merge records in the same dataframe > > Hi: > > Suppose that I have a data frame as below > > x1 x2 x3 ... x10 wk1 wk2 ... Wk208 (these are the column names) > > For each record, x1, x2, x3 ... x10 are attributes. and wk1, > wk2, ..., wk208 are the sales recoreded for this attribute > combination. Suppose that now, that I want to do the following > > 1. Merge the data frame so that I have a new data frame > grouped by values of x2 and x3 (for example). That is, if two > records have the same values of x2 and x3, they should be summed. > > I tried to look at merge, tapply etc. but did not see a fit > with I want to do above. > > Thanks in advance. > > Satish > > ______________________________________________ > R-help at 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. >
Try something like this:
# get column numbers of 'wk' columns
col.num <- grep("^wk", names(yourDF))
# split out only the 'wk' columns
result <- lapply(split(yourDF[, col.num], paste(yourDF$x2,
paste(yourDF$x3))), function(.mrg){
colSums(.mrg)
})
On Thu, Nov 5, 2009 at 4:15 PM, Vadlamani, Satish {FLNA}
<SATISH.VADLAMANI at fritolay.com> wrote:> Hi:
>
> Suppose that I have a data frame as below
>
> x1 x2 x3 ... x10 wk1 wk2 ... Wk208 (these are the column names)
>
> For each record, x1, x2, x3 ... x10 are attributes. and wk1, wk2, ...,
wk208 are the sales recoreded for this attribute combination. Suppose that now,
that I want to do the following
>
> 1. Merge the data frame so that I have a new data frame grouped by values
of x2 and x3 (for example). That is, if two records have the same values of x2
and x3, they should be summed.
>
> I tried to look at merge, tapply etc. but did not see a fit with I want to
do above.
>
> Thanks in advance.
>
> Satish
>
> ______________________________________________
> R-help at 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.
>
--
Jim Holtman
Cincinnati, OH
+1 513 646 9390
What is the problem that you are trying to solve?