On entry to ZGEBAL parameter number 3 had an illegal value

[seyman]

Using ZGEEV, I get the folowing error message :

On entry to ZGEBAL parameter number 3 had an illegal value

Obviously ZGEEV uses ZGEBAL. ZGEBAL parameter number 3 is the input matrix.

In my program I have to get the eigenvalues of a complex(8) hamiltonian matrix.
The issue disapears when I change some terms in my matrix.

Does that mean that my matrix is not diagonalizable, or is it another technical problem?

PS : I'm french, so excuse my language.

[CyLith]

If you look in the source for ZGEBAL, you see that it returns -3 when the input matrix has NaNs in it. So when you changed the entries of the matrix, you must have made the NaNs go away.

[seyman]

Thank you very much, it was so simple ^^