Eigen problem

[pmollo]

Hi,
I have to solve eigen value problems, so I first try to solve a validation example... But it does not work.

Expected behavior
I take a diagonal matrix (4x4) with 4 distinct integers on diagonal, then I use the "EigenValue" function following the help page (https://doc.freefem.org/models/eigen-value-problems.html).
So I expect to find 4 eigen values/vectors, but the function only returns the 3 highest ones.
I try to grow in dimension, but the function always returns the (n-1) highest eigen values.

The code for the example :
`matrix A =
[ [4, 0, 0, 0],
[0, 3 ,0 ,0],
[0, 0, 2, 0],
[0, 0, 0, 5] ];
set(A, solver=UMFPACK);

cout << A << endl;
matrix B =
[ [1, 0, 0, 0],
[0, 1 ,0 ,0],
[0, 0, 1, 0],
[0, 0, 0, 1] ];
set(B, solver=UMFPACK);

// Solve
int Nev = 4 ;
real[int] ev(Nev); //to store eigen values
real[int,int] Vec(Nev,Nev); //to store eigen vectors

int k = EigenValue(A, B, sym=true, value=ev, rawvector=Vec, nev=Nev, maxit=0, ncv=0);
cout << k ;
cout << " vp : " << ev << endl;
cout << " Vp : " << Vec << endl;
`

I try multiple parameters, but I still don't know why it is not working.

Desktop :

• OS: Ubuntu 18.04
• Freefem version : v4.4.2

Thank you for your help,
Pierre.