00001 subroutine interpo_gr2gr_4th(fnc,cfn,rc,thc,phic)
00002   use phys_constant, only : long, pi
00003   use grid_parameter, only : nrg, ntg, npg
00004   use coordinate_grav_extended
00005   implicit none
00006   real(long), pointer     :: fnc(:,:,:)
00007   real(long), intent(out) :: cfn
00008   real(long) ::  rc, thc, phic
00009   real(long) ::  r4(4), th4(4), phi4(4), fr4(4), ft4(4), fp4(4)
00010   integer :: irg, itg, ipg, irgex, itgex, ipgex
00011   integer :: ir0, it0, ip0, irg0 , itg0 , ipg0, ii, jj, kk
00012   real(long), external :: lagint_4th
00013 
00014 
00015 
00016 
00017   cfn = 0.0d0
00018 
00019   do irg = 0, nrg+1
00020     if (rc.lt.rgex(irg).and.rc.ge.rgex(irg-1)) ir0 = min0(irg-2,nrg-3)
00021   end do
00022   do itg = 0, ntg+1
00023     if (thc.lt.thgex(itg).and.thc.ge.thgex(itg-1)) it0 = itg-2
00024   end do
00025   do ipg = 0, npg+1
00026     if (phic.lt.phigex(ipg).and.phic.ge.phigex(ipg-1)) ip0 = ipg-2
00027   end do
00028 
00029   do ii = 1, 4
00030     irg0 = ir0 + ii - 1
00031     itg0 = it0 + ii - 1
00032     ipg0 = ip0 + ii - 1
00033     r4(ii) = rgex(irg0)
00034     th4(ii) = thgex(itg0)
00035     phi4(ii) = phigex(ipg0)
00036   end do
00037 
00038   do kk = 1, 4
00039     ipg0 = ip0 + kk - 1
00040     do jj = 1, 4
00041       itg0 = it0 + jj - 1
00042       do ii = 1, 4
00043         irg0 = ir0 + ii - 1
00044         irgex = irgex_r(irg0)
00045         itgex = itgex_r(itgex_th(itg0),irg0)
00046         ipgex = ipgex_r(ipgex_th(ipgex_phi(ipg0),itg0),irg0)
00047         fr4(ii) = fnc(irgex,itgex,ipgex)
00048       end do
00049       ft4(jj) = lagint_4th(r4,fr4,rc)
00050     end do
00051     fp4(kk) = lagint_4th(th4,ft4,thc)
00052   end do
00053   cfn = lagint_4th(phi4,fp4,phic)
00054 
00055 end subroutine interpo_gr2gr_4th