subroutine da_legtra_inv_adj(jds, jde, jts, jte, max_wavenumber, alp_size, & m, alp, v, r_leg) !----------------------------------------------------------------------- ! Purpose: TBD !----------------------------------------------------------------------- implicit none integer, intent(in) :: jds, jde ! Number of latitudes. integer, intent(in) :: jts, jte ! Number of latitudes. integer, intent(in) :: max_wavenumber ! Maximum wavenumber. integer, intent(in) :: alp_size ! Dimension of ALPs. integer, intent(in) :: m ! Zonal wavenumber. real, intent(in) :: alp(1:alp_size) ! Associated Legendre Polynomials complex, intent(out) :: v(m:max_wavenumber) ! Output spectral coefficient. complex, intent(in) :: r_leg(jts:jte) ! Field to transform. integer :: l, j, js, je ! Loop counters. integer :: index_m, index_j ! Markers. complex :: sum_legtra ! Summation scalars. integer :: jc, iequator, temp if (trace_use) call da_trace_entry("da_legtra_inv_adj") index_m = m * (max_wavenumber + 1 - m) + m * (m + 1) / 2 + 1 - m jc = (jde-jds+1)/2 iequator = mod(jde-jds+1, 2) js = max(jts, jc+iequator+1) je = min(jc+iequator, jte) temp = (max_wavenumber + 1) * (max_wavenumber + 2) / 2 do l = m, max_wavenumber sum_legtra = da_zero_complex if (mod(l+m,2) == 1) then do j = js, jte index_j = (jds+jde - j - 1) * temp sum_legtra = sum_legtra - r_leg(j) * alp(index_j + index_m + l) end do else do j = js, jte index_j = (jds+jde - j - 1) * temp sum_legtra = sum_legtra + r_leg(j) * alp(index_j + index_m + l) end do end if do j = jts, je index_j = (j - 1) * temp sum_legtra = sum_legtra + r_leg(j) * alp(index_j + index_m + l) end do v(l) = sum_legtra end do if (trace_use) call da_trace_exit("da_legtra_inv_adj") end subroutine da_legtra_inv_adj