[R] generating symmetric matrices

[Cleber Borges]

hello


try

?upper.tri

############# example

 p <- 6
 Rmat <- diag(p)
 dat.cor <- rnorm(p*(p-1)/2)
Rmat[upper.tri(Rmat)]<- dat.cor
 Rmat[lower.tri(Rmat)]<- dat.cor


Cleber Borges



> Greetings,
>
> I have a seemingly simple task which I have not been able to solve today. I want to construct a symmetric matrix of arbtriray size w/o using loops. The following I thought would do it:
>
> p <- 6
> Rmat <- diag(p)
> dat.cor <- rnorm(p*(p-1)/2)
> Rmat[outer(1:p, 1:p, "<")] <- Rmat[outer(1:p, 1:p, ">")] <- dat.cor
>
> However, the problem is that the matrix is filled by column and so the resulting matrix is not symmetric.
>
> I'd be grateful for any adive and/or solutions.
>
> Gregory 
>
>   


	

	
		
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Experimente já e veja as novidades.