anchor.diff:        implicit none
         integer          n, m, lwsp, liwsp, itrace, iflag, iwsp(liwsp)
         double precision t, tol, anorm
  -      complex*16       v(n), w(n), wsp(lwsp)
  +      complex(8)       v(n), w(n), wsp(lwsp)
         external         matvec
   
   *-----Purpose----------------------------------------------------------|
  
positive.code: *
  *     matvec : external subroutine for matrix-vector multiplication.
  *              synopsis: matvec( x, y )
  *                        complex*16 x(*), y(*)
  *              computes: y(1:n) <- A*x(1:n)
  *                        where A is the principal matrix.
  *
  
negative.code: *
        integer i,j,k,icoef,mm,ih2,iodd,iused,ifree,iq,ip,iput,iget
        double precision hnorm
        complex(8) cp, cq, scale, scale2, ZERO, ONE
        
        parameter( ZERO=(0.0d0,0.0d0), ONE=(1.0d0,0.0d0) )
        intrinsic ABS, DBLE, INT, LOG, MAX
        complex(8) mycomplex
  
  *---  check restrictions on input parameters ...
        mm = m*m
  