[R] loop not working my way
Rui Barradas
ruipbarradas at sapo.pt
Sat Oct 19 23:03:08 CEST 2013
Hello,
Seems simple.
fun <- function(n = 10){
matd <- matrix(sample(1:30,30, replace=FALSE), ncol=5, nrow=6)
res <- list(mat = NULL, Design_best = matd, Original_design = matd)
trace <- sum(diag(matd))
res$mat <- rbind(res$mat, c(trace = trace, iterations = 0))
for(i in seq_len(n)){
matd <- matrix(sample(1:30,30, replace=FALSE), ncol=5, nrow=6)
if(sum(diag(matd)) < trace){
trace <- sum(diag(matd))
res$mat <- rbind(res$mat, c(trace = trace, iterations = i))
res$Design_best <- matd
}
}
res
}
fun()
fun(20)
Hope this helps,
Rui Barradas
Em 19-10-2013 18:41, laz escreveu:
> Dear R users,
>
> Suppose I want to randomly generate some data, in matrix form, randomly
> swap some of the elements and calculate trace of the matrix for each of
> these stages. If the value of trace obtained in the later is bigger than
> the former, drop the latter matrix and go back to the former matrix,
> swap some elements of the matrix again and calculate the trace. If the
> recent trace is smaller than the previous one, accept the matrix as the
> current . Use the current matrix and swap elements again. repeat the
> whole process for a number of times, say, 10. The output from the
> function should display only the original matrix and its value of trace,
> trace values of successful swaps and their iteration counts and the
> final best matrix that had the smallest value of trace, together with
> its trace value.
>
> For example
> ## original
> > matd<-matrix(sample(1:30,30,replace=FALSE),ncol=5,nrow=6,byrow=FALSE)
> > matd
> [,1] [,2] [,3] [,4] [,5]
> [1,] 12 27 29 16 19
> [2,] 25 10 7 22 13
> [3,] 14 23 3 11 21
> [4,] 28 6 5 2 18
> [5,] 24 20 1 17 26
> [6,] 9 4 30 8 15
> > trace<-sum(diag(matd))
> > trace
> [1] 53
>
> # 1st iteration
>
> [,1] [,2] [,3] [,4] [,5]
> [1,] 24 29 20 25 17
> [2,] 16 1 30 9 5
> [3,] 18 22 2 10 26
> [4,] 23 27 19 21 28
> [5,] 15 6 8 3 13
> [6,] 12 14 7 11 4
> > trace<-sum(diag(matd))
> > trace
> [1] 61
>
> ## drop this matrix because 61 > 53
>
> # 2nd iteration
> > matd<-matrix(sample(1:30,30,replace=FALSE),ncol=5,nrow=6,byrow=FALSE)
> > matd
> [,1] [,2] [,3] [,4] [,5]
> [1,] 2 28 23 15 14
> [2,] 27 9 10 29 7
> [3,] 5 18 12 1 11
> [4,] 8 4 30 16 24
> [5,] 25 19 26 6 13
> [6,] 17 22 3 20 21
> > trace<-sum(diag(matd))
> > trace
> [1] 52
>
> ## accept this matrix because 52 < 53
>
> ### 3rd iteration
> > matd<-matrix(sample(1:30,30,replace=FALSE),ncol=5,nrow=6,byrow=FALSE)
> > matd
> [,1] [,2] [,3] [,4] [,5]
> [1,] 1 29 17 8 6
> [2,] 21 23 10 7 14
> [3,] 22 4 12 26 9
> [4,] 3 13 11 30 15
> [5,] 5 24 18 16 2
> [6,] 20 25 19 27 28
> > trace<-sum(diag(matd))
> > trace
> [1] 68
>
> ## drop this matrix because 68 > 52
>
> ## 4th iteration
> > matd<-matrix(sample(1:30,30,replace=FALSE),ncol=5,nrow=6,byrow=FALSE)
> > matd
> [,1] [,2] [,3] [,4] [,5]
> [1,] 2 6 5 28 15
> [2,] 9 12 13 19 24
> [3,] 3 22 14 11 29
> [4,] 30 20 17 7 23
> [5,] 18 27 21 1 10
> [6,] 25 16 4 8 26
> > trace<-sum(diag(matd))
> > trace
> [1] 45
>
> ## accept this matrix because 45 < 52
>
> The final results will be:
> $mat
> trace iterations
> [1,] 53 0
> [2,] 52 2
> [3,] 45 4
>
> $ Design_best
>
> [,1] [,2] [,3] [,4] [,5]
> [1,] 2 6 5 28 15
> [2,] 9 12 13 19 24
> [3,] 3 22 14 11 29
> [4,] 30 20 17 7 23
> [5,] 18 27 21 1 10
> [6,] 25 16 4 8 26
>
> $ Original_design
>
> [,1] [,2] [,3] [,4] [,5]
> [1,] 12 27 29 16 19
> [2,] 25 10 7 22 13
> [3,] 14 23 3 11 21
> [4,] 28 6 5 2 18
> [5,] 24 20 1 17 26
> [6,] 9 4 30 8 15
>
> Regards,
> Laz
>
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