Re: [Help-gsl] hi :-) \o/ I've some problem with eigensystem

[tuc]

hi
> So the point of question is this: the
> results that i get have the right values but the signs wrong.
>
>    
let A be a square matrix. then a eigenvector v to the eigenvalue a is 
defined to have the property:
    A*v=a*v.

therefor for any real number x (nonzero, zero is never an eigenvector) 
x*v is also a eigenvector of A:
   A*(x*v)=x*(A*v)=x*(a*v)=a*(x*v)

and since (-1) is a real number, mathematically speaking both results 
are correct.

> double data[] = { 0.616556, 0.615444,
>                    0.615444, 0.716556};
>
>
> The right results of eigen value and eigen vector:
>
> eigenvalue= ( 0.04908339 )
>              ( 1.28402771 )
>
>
> eigenvectors = ( -0.735179  -0.677873 )
>                 ( 0.677873    -0.735179 )
>
>
> The value which i took with the sample code instead are this:
>
> eigenvalue = 0.0490843
> eigenvector =
> 0.735179
> -0.677873
> eigenvalue = 1.28403
> eigenvector =
> 0.677873
> 0.735179
>
>