code: def odf(self, sphere=None):
      if sphere is None:
          sphere = self.model.sphere
  
      # Use ascontiguousarray to work around a bug in NumPy
      return np.ascontiguousarray((sphere.vertices * [1, 2, 3]).sum(-1))
  
file_path: dipy/dipy/reconst/tests/test_odf.py
imports: import numpy
  from numpy.testing import assert_equal, assert_almost_equal, assert_
  from dipy.reconst.odf import OdfFit, OdfModel, minmax_normalize, gfa
  from dipy.core.subdivide_octahedron import create_unit_hemisphere
  from dipy.sims.voxel import multi_tensor, multi_tensor_odf
  from dipy.data import get_sphere
  from dipy.core.gradients import gradient_table, GradientTable
label_desc: Use image node_id 1 for calling the SimpleOdfFit obj's underlying member method code with example usage: obj.odf(sphere) and returns: np