calc_unit_basis_vecs Subroutine

subroutine calc_unit_basis_vecs(lon_rad, lat_rad, e_vec, n_vec)

Arguments

Type IntentOptional Attributes Name
real(kind=ESMF_KIND_R8) :: lon_rad
real(kind=ESMF_KIND_R8) :: lat_rad
real(kind=ESMF_KIND_R8) :: e_vec(3)
real(kind=ESMF_KIND_R8) :: n_vec(3)

Called by

proc~~calc_unit_basis_vecs~~CalledByGraph proc~calc_unit_basis_vecs calc_unit_basis_vecs proc~calc_test_field calc_test_field proc~calc_test_field->proc~calc_unit_basis_vecs proc~test_sph_vec_blnr_csg_to_llg test_sph_vec_blnr_csG_to_llG proc~test_sph_vec_blnr_csg_to_llg->proc~calc_unit_basis_vecs proc~test_sph_vec_blnr_csg_to_llg->proc~calc_test_field proc~test_sph_vec_blnr_csg_to_llg_p test_sph_vec_blnr_csG_to_llG_p proc~test_sph_vec_blnr_csg_to_llg_p->proc~calc_unit_basis_vecs proc~test_sph_vec_blnr_csg_to_llg_p->proc~calc_test_field

Source Code

 subroutine calc_unit_basis_vecs(lon_rad, lat_rad, e_vec, n_vec)
   real(ESMF_KIND_R8) :: lon_rad,lat_rad
   real(ESMF_KIND_R8) :: e_vec(3)
   real(ESMF_KIND_R8) :: n_vec(3)
   real(ESMF_KIND_R8) :: e_len, n_len


   ! East vector
   ! [-sin(lng), cos(lng), 0]
   e_vec(1)=-sin(lon_rad)
   e_vec(2)=cos(lon_rad)
   e_vec(3)=0

   ! Make unit vec
   e_len=sqrt(e_vec(1)*e_vec(1) + &
        e_vec(2)*e_vec(2) + &
        e_vec(3)*e_vec(3))

   if (e_len .ne. 0.0) then
      e_vec(1)=e_vec(1)/e_len
      e_vec(2)=e_vec(2)/e_len
      e_vec(3)=e_vec(3)/e_len
   endif


   ! North vector
   ! [-sin(lat) * cos(lng), -sin(lat) * sin(lng), cos(lat)]
   n_vec(1)=-sin(lat_rad)*cos(lon_rad)
   n_vec(2)=-sin(lat_rad)*sin(lon_rad) 
   n_vec(3)=cos(lat_rad)

   
   ! Make unit vec
   n_len=sqrt(n_vec(1)*n_vec(1) + &
              n_vec(2)*n_vec(2) + &
              n_vec(3)*n_vec(3))

   if (n_len .ne. 0.0) then
      n_vec(1)=n_vec(1)/n_len
      n_vec(2)=n_vec(2)/n_len
      n_vec(3)=n_vec(3)/n_len
   endif

 end subroutine calc_unit_basis_vecs