subroutine radb3(Ido,l1,Cc,Ch,Wa1,Wa2)
use fftpack_kind
implicit none
real(rk) :: Cc , Ch , ci2 , ci3 , cr2 , cr3 , di2 , di3 , &
dr2 , dr3 , ti2 , tr2 , Wa1 , Wa2
integer :: i , ic , Ido , idp2 , k , l1
dimension Cc(Ido,3,l1) , Ch(Ido,l1,3) , Wa1(*) , Wa2(*)
real(rk),parameter :: taur = - 0.5_rk
real(rk),parameter :: taui = sqrt(3.0_rk) / 2.0_rk
do k = 1 , l1
tr2 = Cc(Ido,2,k) + Cc(Ido,2,k)
cr2 = Cc(1,1,k) + taur*tr2
Ch(1,k,1) = Cc(1,1,k) + tr2
ci3 = taui*(Cc(1,3,k)+Cc(1,3,k))
Ch(1,k,2) = cr2 - ci3
Ch(1,k,3) = cr2 + ci3
enddo
if ( Ido==1 ) return
idp2 = Ido + 2
do k = 1 , l1
do i = 3 , Ido , 2
ic = idp2 - i
tr2 = Cc(i-1,3,k) + Cc(ic-1,2,k)
cr2 = Cc(i-1,1,k) + taur*tr2
Ch(i-1,k,1) = Cc(i-1,1,k) + tr2
ti2 = Cc(i,3,k) - Cc(ic,2,k)
ci2 = Cc(i,1,k) + taur*ti2
Ch(i,k,1) = Cc(i,1,k) + ti2
cr3 = taui*(Cc(i-1,3,k)-Cc(ic-1,2,k))
ci3 = taui*(Cc(i,3,k)+Cc(ic,2,k))
dr2 = cr2 - ci3
dr3 = cr2 + ci3
di2 = ci2 + cr3
di3 = ci2 - cr3
Ch(i-1,k,2) = Wa1(i-2)*dr2 - Wa1(i-1)*di2
Ch(i,k,2) = Wa1(i-2)*di2 + Wa1(i-1)*dr2
Ch(i-1,k,3) = Wa2(i-2)*dr3 - Wa2(i-1)*di3
Ch(i,k,3) = Wa2(i-2)*di3 + Wa2(i-1)*dr3
enddo
enddo
end subroutine radb3
