subroutine dradf4 (ido,l1,cc,ch,wa1,wa2,wa3)
      double precision cc(ido,l1,4), ch(ido,4,l1), wa1(1), wa2(1),
     1  wa3(1), ci2, ci3, ci4, cr2, cr3, cr4, hsqt2, ti1, ti2, ti3,
     2  ti4, tr1, tr2, tr3, tr4
      data hsqt2 /   .7071067811 8654752440 0844362104 85 d0 /
c
      do 101 k=1,l1
         tr1 = cc(1,k,2)+cc(1,k,4)
         tr2 = cc(1,k,1)+cc(1,k,3)
         ch(1,1,k) = tr1+tr2
         ch(ido,4,k) = tr2-tr1
         ch(ido,2,k) = cc(1,k,1)-cc(1,k,3)
         ch(1,3,k) = cc(1,k,4)-cc(1,k,2)
  101 continue
c
      if (ido-2) 107,105,102
  102 idp2 = ido+2
      do 104 k=1,l1
         do 103 i=3,ido,2
            ic = idp2-i
            cr2 = wa1(i-2)*cc(i-1,k,2)+wa1(i-1)*cc(i,k,2)
            ci2 = wa1(i-2)*cc(i,k,2)-wa1(i-1)*cc(i-1,k,2)
            cr3 = wa2(i-2)*cc(i-1,k,3)+wa2(i-1)*cc(i,k,3)
            ci3 = wa2(i-2)*cc(i,k,3)-wa2(i-1)*cc(i-1,k,3)
            cr4 = wa3(i-2)*cc(i-1,k,4)+wa3(i-1)*cc(i,k,4)
            ci4 = wa3(i-2)*cc(i,k,4)-wa3(i-1)*cc(i-1,k,4)
            tr1 = cr2+cr4
            tr4 = cr4-cr2
            ti1 = ci2+ci4
            ti4 = ci2-ci4
            ti2 = cc(i,k,1)+ci3
            ti3 = cc(i,k,1)-ci3
            tr2 = cc(i-1,k,1)+cr3
            tr3 = cc(i-1,k,1)-cr3
            ch(i-1,1,k) = tr1+tr2
            ch(ic-1,4,k) = tr2-tr1
            ch(i,1,k) = ti1+ti2
            ch(ic,4,k) = ti1-ti2
            ch(i-1,3,k) = ti4+tr3
            ch(ic-1,2,k) = tr3-ti4
            ch(i,3,k) = tr4+ti3
            ch(ic,2,k) = tr4-ti3
  103    continue
  104 continue
      if (mod(ido,2) .eq. 1) return
  105 continue
c
      do 106 k=1,l1
         ti1 = -hsqt2*(cc(ido,k,2)+cc(ido,k,4))
         tr1 = hsqt2*(cc(ido,k,2)-cc(ido,k,4))
         ch(ido,1,k) = tr1+cc(ido,k,1)
         ch(ido,3,k) = cc(ido,k,1)-tr1
         ch(1,2,k) = ti1-cc(ido,k,3)
         ch(1,4,k) = ti1+cc(ido,k,3)
  106 continue
c
  107 return
      end