Thank you Avi,
One question, I am getting this error from this script
> dat %>%
+ + group_by(Year, Sex) %>%
+ + summarize( M = mean(wt, na.rm=TRUE)) %>%
+ + pivot_wider(names_from = Sex, values_from = M) %>%
+ + as.data.frame %>%
+ + round(1)
Error in group_by(Year, Sex) : object 'Year' not found
Why I am getting this?
On Mon, Nov 1, 2021 at 7:07 PM Avi Gross via R-help
<r-help@r-project.org> wrote:
>
> 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,
> > >
> > > ______________________________________________
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> > > PLEASE do read the posting guide
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> > > 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
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> > 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
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> > 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.
______________________________________________
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