R help - Jan 2004 - assign

DeaR useRs:

I would like to assign a values in an object using a loop 'for'.
This is a reduce example of my problem, my real problem is a few
complicated:

for (j in 1:10) {
	x.j<-rnorm(100)
}

I want to create 10 objects as "x.1, x.2, ... , x.9, x.10" with values
in
it.
I used the "assign" function but nothing happens.
Thank you very much

Hi

is it possible for you to use one object (data frame) and assign 
along its collumns?
> x<-rep(0,10)
> x<-cbind(x,x,x,x,x,x)
> x
      x x x x x x
 [1,] 0 0 0 0 0 0
 [2,] 0 0 0 0 0 0
 [3,] 0 0 0 0 0 0
 [4,] 0 0 0 0 0 0
 [5,] 0 0 0 0 0 0
 [6,] 0 0 0 0 0 0
 [7,] 0 0 0 0 0 0
 [8,] 0 0 0 0 0 0
 [9,] 0 0 0 0 0 0
[10,] 0 0 0 0 0 0
> for(i in 1:6) x[,i]<-rnorm(10)

or you can use list in quite similar manner.

Cheers
Petr


On 7 Jan 2004 at 17:53, Perez Martin, Agustin wrote:
> DeaR useRs:
> 
> I would like to assign a values in an object using a loop 'for'.
> This is a reduce example of my problem, my real problem is a few
> complicated:
> 
> for (j in 1:10) {
>  x.j<-rnorm(100)
> }
> 
> I want to create 10 objects as "x.1, x.2, ... , x.9, x.10" with
values
> in it. I used the "assign" function but nothing happens. Thank
you
> very much
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://www.stat.math.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
> http://www.R-project.org/posting-guide.html
Petr Pikal
petr.pikal at precheza.cz

Perez Martin, Agustin wrote:
>DeaR useRs:
>
>I would like to assign a values in an object using a loop 'for'.
>This is a reduce example of my problem, my real problem is a few
>complicated:
>
>for (j in 1:10) {
>	x.j<-rnorm(100)
>}
>
>I want to create 10 objects as "x.1, x.2, ... , x.9, x.10" with
values in
>it.
>I used the "assign" function but nothing happens.
>Thank you very much
>
>______________________________________________
>R-help at stat.math.ethz.ch mailing list
>https://www.stat.math.ethz.ch/mailman/listinfo/r-help
>PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html
>  
>
Use eval or assign:

 > for(j in 1:10)
eval(parse(text=paste("x",j,"<-",j,sep="")))
 > x1
[1] 1
 > x8
[1] 8
 > for(j in 1:10)
eval(parse(text=paste("x",j,"<-rnorm(10)",sep="")))
 > x1
 [1]  0.49045324  0.44842510 -1.18015351 -0.04325187 -0.75345939 -0.99181309
 [7]  0.62517301 -0.68466635  0.33383560 -0.62189500
 > x2
 [1] -0.4344948  2.0276137  1.2783173  1.1170551  0.3546490 -0.0748969
 [7] -0.8817247 -1.4649175 -1.5461995 -0.6575016
 > for(j in 1:10) assign(paste("y",j,sep=""),rnorm(10))
 > y1
 [1] 1.7255925 0.4993323 1.8846513 0.2058971 0.2284036  -3.1971553
 [7]  -0.2629365 0.2724788  -0.9911388  -0.6341857
 > y2
 [1] 0.11301503  -1.28497666 0.40670853 0.08479014 1.05818411  -1.10843908
 [7] 1.30441911  -0.49050833  -1.21438645 0.03923849
ls()
 [1] "j"   "x1"  "x10" "x2" 
"x3"  "x4"  "x5"  "x6"  "x7" 
"x8"  "x9"  "y1"
[13] "y10" "y2"  "y3"  "y4" 
"y5"  "y6"  "y7"  "y8"  "y9"

pw

This is one way:
for (j in 1:10) {
   assign(paste("x", j, sep="."), rnorm(100)) 
}

BTW, there have been many similar posts like this in the past. They are
easily found using the search function at
http://cran.r-project.org/search.html

HTH, Andy

On Wed, 7 Jan 2004, Perez Martin, Agustin wrote:
> DeaR useRs:
> 
> I would like to assign a values in an object using a loop 'for'.
> This is a reduce example of my problem, my real problem is a few
> complicated:
> 
> for (j in 1:10) {
> 	x.j<-rnorm(100)
> }
> 
> I want to create 10 objects as "x.1, x.2, ... , x.9, x.10" with
values in
> it.
Actually, you assigned ten times to object x.j. As was mentioned earlier 
today in reference to a different question, you will almost always find 
that what you think you need and what works best are not the same - a list 
here would be much more convenient:

x <- vector(mode="list", length=10)
for (j in 1:10) {
  x[[j]] <- rnorm(100)
}

for example. For more complicated list elements, the arguments for using 
lists are even stronger. Take a little time to make lists your friends, 
they are powerful and flexible.
> I used the "assign" function but nothing happens.
> Thank you very much
> 
> 
-- 
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Breiviksveien 40, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 93 93
e-mail: Roger.Bivand at nhh.no

Use assign().

varnames <- paste("x", 1:10, sep = ".")
for(j in 1:10) {
	assign(varnames[j], rnorm(10))
}

-roger

Perez Martin, Agustin wrote:
> DeaR useRs:
> 
> I would like to assign a values in an object using a loop 'for'.
> This is a reduce example of my problem, my real problem is a few
> complicated:
> 
> for (j in 1:10) {
> 	x.j<-rnorm(100)
> }
> 
> I want to create 10 objects as "x.1, x.2, ... , x.9, x.10" with
values in
> it.
> I used the "assign" function but nothing happens.
> Thank you very much
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://www.stat.math.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html
>