[R] adding columns to a table after a loop

[Uwe Ligges]

Albert Picado wrote:
> Dear list,
> 
> I am trying to find the way to add columns to a table
> (or a matrix) after a loop. The result of this loop is
> an array and I would like to get all the results in a
> single table once the loop is finish. I have
> reproduced a simplified example below:
> 
>> a<- 1
>> b <- matrix()
>> while (a <= 4) {
> + b<-rnorm(10)
> + a<- a +1
> + }


Staying in your example:

a <- 1
b <- matrix(nrow=10, ncol=4)
while(a <= 4){
     b[,i] <- rnorm(10)
     a <- a + 1
}

Uwe Ligges



> # I have tried several methods but without succes so
> far. 
> 
>> result <- as.data.frame(cbind(b))
>> result
>              b
> 1  -0.03250661
> 2  -0.59823770
> 3   1.58120471
> 4   0.41086546
> 5   0.78959090
> 6   1.23587125
> 7   0.83427190
> 8   1.09035581
> 9   0.11331056
> 10  0.25267231
> 
> the result above is not what I am looking for because
> it shows only the results from the last operation in
> the loop, I would like to obtain something like the
> following.
> 
>> result
>             b1         b2          b3         b4
> 1  -0.08420826 -0.0637943 -0.83246201 -1.0902384
> 2   0.40623009 -2.7940096  1.37664973  1.6023967
> 3  -1.13850505  1.1660669 -0.95962296 -0.7325098
> 4  -1.06183391  1.1063677  1.67948677 -1.9875475
> 5  -0.64431067 -0.4843952 -1.30742858  0.5064134
> 6   0.56729468  1.0860484  0.07651954  0.4380108
> 7   0.95036177 -0.5328609  1.28954934 -0.2775614
> 8  -0.17848223  0.5340379 -0.22613700  1.0179886
> 9   2.93145454 -1.8639607 -0.25478610  1.6619754
> 10  1.51942415 -0.2051423  0.09144450 -1.6329481
> 
> I hope someone can give me a hand
> 
> best regards
> 
> a
> 
> 
> 
> 
> 	
>  p5.vert.ukl.yahoo.com uncompressed/chunked Sat Aug 12 13:14:00 GMT 2006
> 
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