def METHOD_NAME():
    data, gtab = dsi_voxels()
    DS = DiffusionSpectrumModel(gtab)
    DSfit = DS.fit(data)
    PDF = DSfit.pdf()
    assert_equal(data.shape[:-1] + (17, 17, 17), PDF.shape)
    assert_equal(np.alltrue(np.isreal(PDF)), True)