subroutine nonlin(density1,u_par1,t_par1,q_par1,
     >     t_perp1,q_perp1,phi)

      implicit none
      include 'itg.par'
      include 'itg.cmn'
      include 'itg.mom'
      
      complex phi(lz,mz,nz)
      integer i
c
c We must calculate {a,b} for a,b=:
c uv,w		uv,tpar		uv,v		uv,T
c uv,q		uv,qpar		uflr,w		uflr,T
c uflr,v	uflr2,T		uflr2,q
c
c In each case we want to pass the two variables' real and
c imaginary parts to a subroutine which will return the real
c and imaginary parts of {a,b} in (x,ky,kz) space.
c 
c     
c Usual NL terms unless iflr=6, then do like Ron 
c
      if (iflr.ne.6) then
      do i=1,nspecies
         call nlpsc(0,phi_flr2(1,1,1,i),t_perp1(1,1,1,i),
     .        nl_tperp3(1,1,1,i))
         call nlpsc(2,phi_flr1(1,1,1,i),t_perp1(1,1,1,i),
     .        nl_density2(1,1,1,i))
         call nlpsc(1,phi_flr1(1,1,1,i),density1(1,1,1,i),
     .        nl_tperp2(1,1,1,i))
         call nlpsc(2,phi_u(1,1,1,i),density1(1,1,1,i),
     .        nl_density1(1,1,1,i))
         call nlpsc(1,phi_u(1,1,1,i),t_par1(1,1,1,i),
     .        nl_tpar(1,1,1,i))
         call nlpsc(1,phi_u(1,1,1,i),u_par1(1,1,1,i),
     .        nl_upar1(1,1,1,i))
         call nlpsc(1,phi_u(1,1,1,i),t_perp1(1,1,1,i),
     .        nl_tperp1(1,1,1,i))
c     
         if(nparmom.eq.4) 
     .        call nlpsc(1,phi_u(1,1,1,i),q_par1(1,1,1,i),
     .        nl_qpar(1,1,1,i))
c     
         if(nperpmom.eq.2) then
            call nlpsc(1,phi_u(1,1,1,i),q_perp1(1,1,1,i),
     .           nl_qperp1(1,1,1,i))
            call nlpsc(2,phi_flr2(1,1,1,i),q_perp1(1,1,1,i),
     .           nl_qperp3(1,1,1,i))
            call nlpsc(2,phi_flr1(1,1,1,i),q_perp1(1,1,1,i),
     .           nl_upar2(1,1,1,i))
            call nlpsc(1,phi_flr1(1,1,1,i),u_par1(1,1,1,i),
     .           nl_qperp2(1,1,1,i))
         endif     
      enddo
      else
c     
c Like Ron (3+1 assumed)    
c     
      do i=1,nspecies
         call nlpsc(0,phi,density1(1,1,1,i),nl_density1(1,1,1,i))
         call nlpsc(1,phi,u_par1(1,1,1,i),nl_upar1(1,1,1,i))
         call nlpsc(1,phi,t_par1(1,1,1,i),nl_tpar(1,1,1,i))
         call nlpsc(1,phi,t_perp1(1,1,1,i),nl_tperp1(1,1,1,i))
      enddo
      endif 

      return
      end