subroutine radb2(Ido,l1,Cc,Ch,Wa1)
use fftpack_kind
implicit none
real(rk) :: Cc , Ch , ti2 , tr2 , Wa1
integer :: i , ic , Ido , idp2 , k , l1
dimension Cc(Ido,2,l1) , Ch(Ido,l1,2) , Wa1(*)
do k = 1 , l1
Ch(1,k,1) = Cc(1,1,k) + Cc(Ido,2,k)
Ch(1,k,2) = Cc(1,1,k) - Cc(Ido,2,k)
enddo
if ( Ido<2 ) return
if ( Ido/=2 ) then
idp2 = Ido + 2
do k = 1 , l1
do i = 3 , Ido , 2
ic = idp2 - i
Ch(i-1,k,1) = Cc(i-1,1,k) + Cc(ic-1,2,k)
tr2 = Cc(i-1,1,k) - Cc(ic-1,2,k)
Ch(i,k,1) = Cc(i,1,k) - Cc(ic,2,k)
ti2 = Cc(i,1,k) + Cc(ic,2,k)
Ch(i-1,k,2) = Wa1(i-2)*tr2 - Wa1(i-1)*ti2
Ch(i,k,2) = Wa1(i-2)*ti2 + Wa1(i-1)*tr2
enddo
enddo
if ( mod(Ido,2)==1 ) return
endif
do k = 1 , l1
Ch(Ido,k,1) = Cc(Ido,1,k) + Cc(Ido,1,k)
Ch(Ido,k,2) = -(Cc(1,2,k)+Cc(1,2,k))
enddo
end subroutine radb2
