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Loop on vector name

5 messages · Megh Dal, Henrique Dallazuanna, Dimitris Rizopoulos +1 more

Original
Megh Dal
# 
[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,
Dimitris Rizopoulos
# 
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:

  
    

      
      
    

  


  


      

    

    

      
      

        


  

        

      Greg Snow
    

    

      
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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:

            

      
      
      
    

        
Now your loop can be:

            

      
      
      
    

        
Or even simpler:

            

      
      
      
    

        
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,

            

      
      
      
    

        

      
      
    

  
  


  


      

    

    
1 day later

    

      
      

        


  

        

      Megh Dal
    

    

      
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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: