code: def _do_sphere_field(rrs, rmags, cosmags, ws, bins, r0):
      n_coils = bins[-1] + 1
      # Shift to the sphere model coordinates
      rrs = rrs - r0
      B = np.zeros((3 * len(rrs), n_coils))
      for ri in range(len(rrs)):
          rr = rrs[ri]
          # Check for a dipole at the origin
          if np.sqrt(np.dot(rr, rr)) <= 1e-10:
              continue
          this_poss = rmags - r0
  
          # Vector from dipole to the field point
          a_vec = this_poss - rr
          a = np.sqrt(np.sum(a_vec * a_vec, axis=1))
          r = np.sqrt(np.sum(this_poss * this_poss, axis=1))
          rr0 = np.sum(this_poss * rr, axis=1)
          ar = (r * r) - rr0
          ar0 = ar / a
          F = a * (r * a + ar)
          gr = (a * a) / r + ar0 + 2.0 * (a + r)
          g0 = a + 2 * r + ar0
          # Compute the dot products needed
          re = np.sum(this_poss * cosmags, axis=1)
          r0e = np.sum(rr * cosmags, axis=1)
          g = (g0 * r0e - gr * re) / (F * F)
          good = (a > 0) | (r > 0) | ((a * r) + 1 > 1e-5)
          rr_ = rr.reshape(1, 3)
          v1 = np.empty((cosmags.shape[0], 3))
          _jit_cross(v1, rr_, cosmags)
          v2 = np.empty((cosmags.shape[0], 3))
          _jit_cross(v2, rr_, this_poss)
          xx = (good * ws).reshape(-1, 1) * (
              v1 / F.reshape(-1, 1) + v2 * g.reshape(-1, 1)
          )
          for jj in range(3):
              zz = bincount(bins, xx[:, jj], n_coils)
              B[3 * ri + jj, :] = zz
      B *= _MAG_FACTOR
      return B
  
imports: from copy import deepcopy
  import numpy
  from .._fiff.constants import FIFF
  from ..bem import _import_openmeeg, _make_openmeeg_geometry
  from ..fixes import bincount, jit
  from ..parallel import parallel_func
  from ..surface import _jit_cross, _project_onto_surface
  from ..transforms import apply_trans, invert_transform
  from ..utils import _check_option, _pl, fill_doc, logger, verbose, warn
label_desc: Use image node_id 16 for calling a global function with example usage: _do_sphere_field(rrs, rmags, cosmags, ws, bins, r0) and returns: B