R help - Jul 2008 - question about a small "for" loop

Christopher W. Ryan wrote:
> R 2.5.1 on WinXP
> 
> I'm trying to create new variables in a dataframe called jaw, as powers
> of jaw$age up to the sixth power, and name them
> 
> jaw$age.(--the digit corresponding to the power--)
> 
> Obviously none of these work (silly for me to try, I suppose):
> 
> for (i in 2:6) {
>   jaw$age.'i' <- jaw$age^i
>   }
> 
> for (i in 2:6) {
>   jaw$age.i <- jaw$age^i
>   }
> 
> for (i in 2:6) {
>   jaw$age."i" <- jaw$age^i
>   }
> 
> What is the proper syntax to create and name these variables all at once?
> 
> Thanks.
> 
> --Chris

for (i in 2:6)
    jaw[[paste("age", i, sep="^")]] = jaw$age^i


or

  m = outer(jaw$age, 2:6, "^")
  colnames(m) = paste("age", 2:6, sep="^")
  jaw = cbind(jaw, m)


Best wishes
  Wolfgang


-- 
----------------------------------------------------
Wolfgang Huber, EMBL-EBI, http://www.ebi.ac.uk/huber

May be this helps:


jaw<-data.frame(vara=1:20,age=runif(20))

for (i in 2:6)  {
 jaw[paste("agepow",i, sep="")] <- jaw["age"]^i
 }

jaw<-round(jaw,2) # It is just to help the check task



Cheers,



Miltinho Astronauta

Brazil






On 7/14/08, Christopher W. Ryan <cryan@binghamton.edu>
wrote:
>
> R 2.5.1 on WinXP
>
> I'm trying to create new variables in a dataframe called jaw, as powers
> of jaw$age up to the sixth power, and name them
>
> jaw$age.(--the digit corresponding to the power--)
>
> Obviously none of these work (silly for me to try, I suppose):
>
> for (i in 2:6) {
> jaw$age.'i' <- jaw$age^i
> }
>
> for (i in 2:6) {
> jaw$age.i <- jaw$age^i
> }
>
> for (i in 2:6) {
> jaw$age."i" <- jaw$age^i
> }
>
> What is the proper syntax to create and name these variables all at once?
>
> Thanks.
>
> --Chris
> --
> Christopher W. Ryan, MD
> SUNY Upstate Medical University Clinical Campus at Binghamton
> 40 Arch Street, Johnson City, NY  13790
> cryanatbinghamtondotedu
> PGP public keys available at http://home.stny.rr.com/ryancw/
>
> "If you want to build a ship, don't drum up the men to gather
wood,
> divide the work and give orders. Instead, teach them to yearn for the
> vast and endless sea."  [Antoine de St. Exupery]
>
> ______________________________________________
> 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.
>
	[[alternative HTML version deleted]]

R 2.5.1 on WinXP

I'm trying to create new variables in a dataframe called jaw, as powers
of jaw$age up to the sixth power, and name them

jaw$age.(--the digit corresponding to the power--)

Obviously none of these work (silly for me to try, I suppose):

for (i in 2:6) {
  jaw$age.'i' <- jaw$age^i
  }

for (i in 2:6) {
  jaw$age.i <- jaw$age^i
  }

for (i in 2:6) {
  jaw$age."i" <- jaw$age^i
  }

What is the proper syntax to create and name these variables all at once?

Thanks.

--Chris
-- 
Christopher W. Ryan, MD
SUNY Upstate Medical University Clinical Campus at Binghamton
40 Arch Street, Johnson City, NY  13790
cryanatbinghamtondotedu
PGP public keys available at http://home.stny.rr.com/ryancw/

"If you want to build a ship, don't drum up the men to gather wood,
divide the work and give orders. Instead, teach them to yearn for the
vast and endless sea."  [Antoine de St. Exupery]