o. If PETSc is
configured with complex scalars the eigenvector is stored
directly in Vr (Vi is set to zero). In any case, the user can pass NULL in Vr
or Vi if one of them is not required.
<P>
The index i should be a value between 0 and nconv-1 (see <A HREF="../EPS/EPSGetConverged.html#EPSGetConverged">EPSGetConverged</A>()).
Eigenpairs are indexed according to the ordering criterion established
with <A HREF="../EPS/EPSSetWhichEigenpairs.html#EPSSetWhichEigenpairs">EPSSetWhichEigenpairs</A>().
<P>
The 2-nor