subroutine eigen(n,a,evalue,z)

        implicit double precision (o-z, a-h)
        include "parameters.dat"
        double complex evalue
        dimension a(nd1,nd1),evalue(nd1),z(nd1,nd1)
     &   ,wr(nd1),wi(nd1),fv1(nd1),iv1(nd1)

        call BALANC(nd1,n,a,is1,is2,fv1)

        call ELMHES(nd1,n,is1,is2,a,iv1)

        call ELTRAN(nd1,n,is1,is2,a,iv1,z)

        call HQR2(nd1,n,is1,is2,a,wr,wi,z,ierr)

        if (ierr .ne. 0) goto 999

        call BALBAK(nd1,n,is1,is2,fv1,n,z)

        do i = 1, n
           evalue(i) = dcmplx(wr(i),wi(i))
        end do

        return

 999    write(Unit=*,fmt=*) ' ierr = ',ierr
        stop

        end