Thank you all!
I can assure you that this is not HW. This is a sample of my large
data set and I want a simple and efficient approach to get the
desired output in that particular format. That file will be saved
and used as an input file for another external process.
val
On Mon, Nov 1, 2021 at 6:08 PM Avi Gross via R-help
<r-help at r-project.org> wrote:>
> Jim,
>
> Your code gives the output in quite a different format and as an object of
> class "by" that is not easily convertible to a data.frame. So,
yes, it is an
> answer that produces the right numbers but not in the places or data
> structures I think they (or if it is HW ...) wanted.
>
> Trivial standard cases are often handled by a single step but more complex
> ones often suggest a multi-part approach.
>
> Of course Val gets to decide what approach works best for them within
> whatever constraints we here are not made aware of. If this is a class
> assignment, it likely would be using only tools discussed in the class. So
I
> would not suggest using a dplyr/tidyverse approach if that is not covered
or
> even part of a class. If this is a project in the real world, it becomes a
> matter of programming taste and convenience and so on.
>
> Maybe Val can share more about the situation so we can see what is helpful
> and what is not. Realistically, I can think of way too many ways to get the
> required output.
>
> -----Original Message-----
> From: R-help <r-help-bounces at r-project.org> On Behalf Of Jim Lemon
> Sent: Monday, November 1, 2021 6:25 PM
> To: Val <valkremk at gmail.com>; r-help mailing list <r-help at
r-project.org>
> Subject: Re: [R] by group
>
> Hi Val,
> I think you answered your own question:
>
> by(dat$wt,dat[,c("Sex","Year")],mean)
>
> Jim
>
> On Tue, Nov 2, 2021 at 8:09 AM Val <valkremk at gmail.com> wrote:
> >
> > Hi All,
> >
> > How can I generate mean by group. The sample data looks like as
> > follow, dat<-read.table(text="Year Sex wt
> > 2001 M 15
> > 2001 M 14
> > 2001 M 16
> > 2001 F 12
> > 2001 F 11
> > 2001 F 13
> > 2002 M 14
> > 2002 M 18
> > 2002 M 17
> > 2002 F 11
> > 2002 F 15
> > 2002 F 14
> > 2003 M 18
> > 2003 M 13
> > 2003 M 14
> > 2003 F 15
> > 2003 F 10
> > 2003 F 11 ",header=TRUE)
> >
> > The desired output is,
> > M F
> > 2001 15 12
> > 2002 16.33 13.33
> > 2003 15 12
> >
> > Thank you,
> >
> > ______________________________________________
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> > PLEASE do read the posting guide
> > http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.