Search code examples
reigenvectoreigenvalue

How to obtain eigen vectors from particular eigen values using R?

Example: I have 20 eigen values and i have chosen 10 as best eigen values. For these 10 values I need to find eigen vectors seperately.How to do? I am new to R programming. Expecting your reply.

Solution 
  • > B <- matrix(1:4, 2)
> eig <- eigen(B)
> eig$vectors[,which.max(eig$values)]
[1] -0.5657675 -0.8245648

    or something like this

    > n <- 3 
> A  <- matrix(round(runif(n*n),2),nrow=n) 
> A 
     [,1] [,2] [,3]
[1,] 0.54 0.90 0.82
[2,] 0.09 0.42 0.95
[3,] 0.17 0.75 0.69
> evv.A <- eigen(A) 
> evv.A 
$values
[1]  1.6230202  0.3095823 -0.2826025

$vectors
           [,1]        [,2]       [,3]
[1,] -0.7455955 -0.97996498  0.3069212
[2,] -0.4464598  0.18600090 -0.7788676
[3,] -0.4947332  0.07122006  0.5469594

> 
> k <- which(abs(evv.A$values)==max(abs(evv.A$values))) 
> evv.A$vectors[,k] 
[1] -0.7455955 -0.4464598 -0.4947332
> k 
[1] 1