Understood Val. So you need to save the output in something like a data.frame
which can then be saved as a CSV file or whatever else makes sense to be read
in by a later program. As note by() does not produce the output in a usable way.
But you mentioned efficient, and that is another whole ball of wax. For small
amounts of data it may not matter much. And some processes may look slower but
turn out be more efficient if compiled as C/C++ or ...
Sometimes it might be more efficient to change the format of your data before
the analysis, albeit if the output is much smaller, maybe best later.
Good luck.
-----Original Message-----
From: Val <valkr...@gmail.com>
Sent: Monday, November 1, 2021 7:44 PM
To: Avi Gross <avigr...@verizon.net>
Cc: r-help mailing list <r-help@r-project.org>
Subject: Re: [R] by group
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@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-boun...@r-project.org> On Behalf Of Jim Lemon
> Sent: Monday, November 1, 2021 6:25 PM
> To: Val <valkr...@gmail.com>; r-help mailing list
> <r-help@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 <valkr...@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,
> >
> > ______________________________________________
> > R-help@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@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@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@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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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.
