[My previous message rejected, therefore I am sending same one with some
modification]
I have 3 vectors with object name : dat1, dat2, dat3
Now I want to create a loop, like :
for (i in 1:3)
{
cat(sd(dati))
}
How I can do this in R?
Regards,
Try this: sapply(ls(patt="^dat[0-9]"), function(x)sd(get(x))) On Wed, Sep 17, 2008 at 8:50 AM, Megh Dal <megh700004@yahoo.com> wrote:> [My previous message rejected, therefore I am sending same one with some > modification] > > I have 3 vectors with object name : dat1, dat2, dat3 > > Now I want to create a loop, like : > > for (i in 1:3) > { > cat(sd(dati)) > } > > How I can do this in R? > > Regards, > > ______________________________________________ > 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. >-- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40" S 49° 16' 22" O [[alternative HTML version deleted]]
you need to get(), e.g., try this:
dat1 <- rnorm(5)
dat2 <- rnorm(6)
dat3 <- rnorm(7)
lis <- lapply(paste("dat", 1:3, sep = ""), get)
lis
sapply(lis, sd)
I hope it helps.
Best,
Dimitris
Megh Dal wrote:> [My previous message rejected, therefore I am sending same one with some
modification]
>
> I have 3 vectors with object name : dat1, dat2, dat3
>
> Now I want to create a loop, like :
>
> for (i in 1:3)
> {
> cat(sd(dati))
> }
>
> How I can do this in R?
>
> Regards,
>
> ______________________________________________
> 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.
>
--
Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus Medical Center
Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands
Tel: +31/(0)10/7043478
Fax: +31/(0)10/7043014
Others have answered the question that you asked (it is also a variation of Faq 7.21), but here is an answer to the question that you should have asked: When working with datasets like this, it is better to create a list rather than separate objects with names like dat1, dat2, etc. For example:> mydat <- list(dat1=rnorm(10), dat2=rnorm(25), dat3=runif(100))Now your loop can be:> for(i in 1:3) cat( sd( mydat[[i]] ) )Or even simpler:> sapply( mydat, sd )And when you are through with the data, you only need to delete one object, or copy one object, or save one object, etc. Hope this helps,> -----Original Message----- > From: r-help-bounces at r-project.org [mailto:r-help-bounces at r- > project.org] On Behalf Of Megh Dal > Sent: Wednesday, September 17, 2008 5:51 AM > To: r-help at stat.math.ethz.ch > Subject: [R] Loop on vector name > > [My previous message rejected, therefore I am sending same one with > some modification] > > I have 3 vectors with object name : dat1, dat2, dat3 > > Now I want to create a loop, like : > > for (i in 1:3) > { > cat(sd(dati)) > } > > How I can do this in R? > > Regards, > > ______________________________________________ > 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.
Thanks for this mail. It runs perfectly, but now I stuck on how to convert the result in a vector format for further matrix-compputation. e.g. How to convert "sapply(lis, sd)" to vector? --- On Wed, 9/17/08, Dimitris Rizopoulos <d.rizopoulos at erasmusmc.nl> wrote:> From: Dimitris Rizopoulos <d.rizopoulos at erasmusmc.nl> > Subject: Re: [R] Loop on vector name > To: megh700004 at yahoo.com > Cc: r-help at stat.math.ethz.ch > Date: Wednesday, September 17, 2008, 5:32 PM > you need to get(), e.g., try this: > > dat1 <- rnorm(5) > dat2 <- rnorm(6) > dat3 <- rnorm(7) > > lis <- lapply(paste("dat", 1:3, sep > ""), get) > lis > sapply(lis, sd) > > > I hope it helps. > > Best, > Dimitris > > > Megh Dal wrote: > > [My previous message rejected, therefore I am sending > same one with some modification] > > > > I have 3 vectors with object name : dat1, dat2, dat3 > > > > Now I want to create a loop, like : > > > > for (i in 1:3) > > { > > cat(sd(dati)) > > } > > > > How I can do this in R? > > > > Regards, > > > > ______________________________________________ > > 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. > > > > -- > Dimitris Rizopoulos > Assistant Professor > Department of Biostatistics > Erasmus Medical Center > > Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands > Tel: +31/(0)10/7043478 > Fax: +31/(0)10/7043014
oh god!! I used lapply() instead sapply(). Now it is ok. Thank you so much. By the way after a long time I saw your post. Hope you are well and everything going on fine :) --- On Fri, 9/19/08, markleeds at verizon.net <markleeds at verizon.net> wrote:> From: markleeds at verizon.net <markleeds at verizon.net> > Subject: Re: [R] Loop on vector name > To: megh700004 at yahoo.com > Date: Friday, September 19, 2008, 11:20 AM > hi: i'm not sure if i'm understanding your question > because the sapply > output is a vector. see below. > > > dat1 <- rnorm(5) > dat2 <- rnorm(6) > dat3 <- rnorm(7) > > lis <- lapply(paste("dat", 1:3, sep > ""), get) > lis > output <- sapply(lis, sd) > print(output) > print(str(output)) > > > > On Fri, Sep 19, 2008 at 1:44 AM, Megh Dal wrote: > > > Thanks for this mail. It runs perfectly, but now I > stuck on how to > > convert the result in a vector format for further > matrix-compputation. > > e.g. How to convert "sapply(lis, sd)" to > vector? > > > > > > > > --- On Wed, 9/17/08, Dimitris Rizopoulos > <d.rizopoulos at erasmusmc.nl> > > wrote: > > > >> From: Dimitris Rizopoulos > <d.rizopoulos at erasmusmc.nl> > >> Subject: Re: [R] Loop on vector name > >> To: megh700004 at yahoo.com > >> Cc: r-help at stat.math.ethz.ch > >> Date: Wednesday, September 17, 2008, 5:32 PM > >> you need to get(), e.g., try this: > >> > >> dat1 <- rnorm(5) > >> dat2 <- rnorm(6) > >> dat3 <- rnorm(7) > >> > >> lis <- lapply(paste("dat", 1:3, sep > >> ""), get) > >> lis > >> sapply(lis, sd) > >> > >> > >> I hope it helps. > >> > >> Best, > >> Dimitris > >> > >> > >> Megh Dal wrote: > >>> [My previous message rejected, therefore I am > sending > >> same one with some modification] > >>> > >>> I have 3 vectors with object name : dat1, > dat2, dat3 > >>> > >>> Now I want to create a loop, like : > >>> > >>> for (i in 1:3) > >>> { > >>> cat(sd(dati)) > >>> } > >>> > >>> How I can do this in R? > >>> > >>> Regards, > >>> > >>> ______________________________________________ > >>> 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. > >>> > >> > >> -- > >> Dimitris Rizopoulos > >> Assistant Professor > >> Department of Biostatistics > >> Erasmus Medical Center > >> > >> Address: PO Box 2040, 3000 CA Rotterdam, the > Netherlands > >> Tel: +31/(0)10/7043478 > >> Fax: +31/(0)10/7043014 > > > > ______________________________________________ > > 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.