subroutine rayset
c     ===================
c  
c     set up a table of Rayleigh scattering opacity
c
      INCLUDE 'IMPLIC.FOR'
      INCLUDE 'BASICS.FOR'
      INCLUDE 'MODELQ.FOR'
c
      do id=1,nd
        t=temp(id)
        rho=dens(id)
c
        if(numtemp.eq.nd) then
           opac=raytab(id,1)
           go to 10
        end if
c
        TL=LOG(T)
        DELTAT=(TL-TTAB1)/(TTAB2-TTAB1)*FLOAT(numtemp-1)
        JT = 1 + IDINT(DELTAT)
        JU = JT + 1
        IF(JT.LT.1) JT = 1
        IF(JT.GT.numtemp-1) JT = numtemp-1
        t1i=tempvec(jt)
        t2i=tempvec(jt+1)
        dti=(TL-T1i)/(T2i-T1i)
        if(deltat.lt.0.) dti = 0.d0
C
        if(numrho.gt.1) then
           rtab1=rhomat(jt,1)
           rtab2=rhomat(jt,numrho)
           RL = LOG(RHO)
           DELTAR=(RL-RTAB1)/(RTAB2-RTAB1)*FLOAT(numrho-1)
           JR = 1 + IDINT(DELTAR)
           IF(JR.LT.1) JR = 1
           IF(JR.GT.(numrho-1)) JR = numrho-1
           r1i=rhomat(jt,jr)
           r2i=rhomat(jt,jr+1)
           dri=(RL-R1i)/(R2i-R1i)
           if(deltar.lt.0.) dri = 0.d0
           opr1=raytab(jt,jr)+
     *        dri*(raytab(jt,jr+1)-raytab(jt,jr))
c
           rtab1=rhomat(ju,1)
           rtab2=rhomat(ju,numrho)
           RL = LOG(RHO)
           DELTAR=(RL-RTAB1)/(RTAB2-RTAB1)*FLOAT(numrho-1)
           JR = 1 + IDINT(DELTAR)
           IF(JR.LT.1) JR = 1
           IF(JR.GT.(numrho-1)) JR = numrho-1
           r1i=rhomat(ju,jr)
           r2i=rhomat(ju,jr+1)
           dri=(RL-R1i)/(R2i-R1i)
           if(deltar.lt.0.) dri = 0.d0
           opr2=raytab(ju,jr)+
     *        dri*(raytab(ju,jr+1)-raytab(ju,jr))
c
           opac=opr1+(opr2-opr1)*dti
         else
           jr=1
           opac=raytab(jt,jr)+(raytab(ju,jr)-raytab(jt,jr))*dti
        end if
   10   continue
        raysc(id)=exp(opac)
      end do
      return
      end