れ螻 螳 . 
(A <- matrix(c(1,6,5,2), nrow=2, byrow=T))
(u <- matrix(c(6,-5), nrow=2, byrow=T))
(v <- matrix(c(3,-1), nrow=2, byrow=T))

蟆郁骸
> (A <- matrix(c(1,6,5,2), nrow=2, byrow=T))
     [,1] [,2]
[1,]    1    6
[2,]    5    2
> (u <- matrix(c(6,-5), nrow=2, byrow=T))
     [,1]
[1,]    6
[2,]   -5
> (v <- matrix(c(3,-1), nrow=2, byrow=T))
     [,1]
[1,]    3
[2,]   -1

A 螻螳螻 螻覯″磯 れ螻 螳. 
> eigen(A)
$values
[1]  7 -4

$vectors
           [,1]       [,2]
[1,] -0.7071068 -0.7682213
[2,] -0.7071068  0.6401844

u, v螳 A 螻螳 螻覯″一語 覲 覲伎. 襾殊 襯 襷れ. 螻覯″一企 螻螳 覓伎語 print螻, T襯 覦. 螻覯″郁 覃 F襯 覦.
udf_is_eigenvector <- function(A, u){
    is_eigenvector <- F
    for (eval in eigen(A)$values){
        if (identical(A%*%u, u*eval) == T){
            is_eigenvector <- T
            print(paste0("eigen value = ", eval))
            break
        }
    }
    return(is_eigenvector)
}

覲蟆郁骸
> udf_is_eigenvector(A, u)
[1] "eigen value = -4"
[1] TRUE
> udf_is_eigenvector(A, v)
[1] FALSE