Modify the outward, k=0 
k=N, version of
``func_Schrodinger'' to be able call your modified ``schint'' by placing
a dummy argument in the slot for Psiout. (If you are working in
C, just use NULL for the Psiout argument in the call. If you are
working in Fortran, you can just send any double variable, such
as Psi.) The prototype for ``func_Schrodinger'' should not change.