def _compare_positions(a, b, max_dist=0.003, max_angle=5.):
    """Compare estimated cHPI positions"""
    from scipy.interpolate import interp1d
    trans, rot, t = a
    trans_est, rot_est, t_est = b
    quats_est = _rot_to_quat(rot_est)

    # maxfilter produces some times that are implausibly large (weird)
    use_mask = (t >= t_est[0]) & (t <= t_est[-1])
    t = t[use_mask]
    trans = trans[use_mask]
    quats = _rot_to_quat(rot)
    quats = quats[use_mask]

    # double-check our angle function
    for q in (quats, quats_est):
        angles = _angle_between_quats(q, q)
        assert_allclose(angles, 0., atol=1e-5)

    # < 3 mm translation difference between MF and our estimation
    trans_est_interp = interp1d(t_est, trans_est, axis=0)(t)
    worst = np.sqrt(np.sum((trans - trans_est_interp) ** 2, axis=1)).max()
    assert_true(worst <= max_dist, '%0.1f > %0.1f mm'
                % (1000 * worst, 1000 * max_dist))

    # < 5 degrees rotation difference between MF and our estimation
    # (note that the interpolation will make this slightly worse)
    quats_est_interp = interp1d(t_est, quats_est, axis=0)(t)
    worst = 180 * _angle_between_quats(quats_est_interp, quats).max() / np.pi
    assert_true(worst <= max_angle, '%0.1f > %0.1f deg' % (worst, max_angle,))
示例#2
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def _compare_positions(a, b, max_dist=0.003, max_angle=5.):
    """Compare estimated cHPI positions"""
    from scipy.interpolate import interp1d
    trans, rot, t = a
    trans_est, rot_est, t_est = b
    quats_est = _rot_to_quat(rot_est)

    # maxfilter produces some times that are implausibly large (weird)
    use_mask = (t >= t_est[0]) & (t <= t_est[-1])
    t = t[use_mask]
    trans = trans[use_mask]
    quats = _rot_to_quat(rot)
    quats = quats[use_mask]

    # double-check our angle function
    for q in (quats, quats_est):
        angles = _angle_between_quats(q, q)
        assert_allclose(angles, 0., atol=1e-5)

    # < 3 mm translation difference between MF and our estimation
    trans_est_interp = interp1d(t_est, trans_est, axis=0)(t)
    worst = np.sqrt(np.sum((trans - trans_est_interp)**2, axis=1)).max()
    assert_true(worst <= max_dist,
                '%0.1f > %0.1f mm' % (1000 * worst, 1000 * max_dist))

    # < 5 degrees rotation difference between MF and our estimation
    # (note that the interpolation will make this slightly worse)
    quats_est_interp = interp1d(t_est, quats_est, axis=0)(t)
    worst = 180 * _angle_between_quats(quats_est_interp, quats).max() / np.pi
    assert_true(worst <= max_angle, '%0.1f > %0.1f deg' % (
        worst,
        max_angle,
    ))
def test_quaternions():
    """Test quaternion calculations
    """
    rots = [np.eye(3)]
    for fname in [test_fif_fname, ctf_fname, hp_fif_fname]:
        rots += [read_info(fname)['dev_head_t']['trans'][:3, :3]]
    for rot in rots:
        assert_allclose(rot,
                        _quat_to_rot(_rot_to_quat(rot)),
                        rtol=1e-5,
                        atol=1e-5)
        rot = rot[np.newaxis, np.newaxis, :, :]
        assert_allclose(rot,
                        _quat_to_rot(_rot_to_quat(rot)),
                        rtol=1e-5,
                        atol=1e-5)

    # let's make sure our angle function works in some reasonable way
    for ii in range(3):
        for jj in range(3):
            a = np.zeros(3)
            b = np.zeros(3)
            a[ii] = 1.
            b[jj] = 1.
            expected = np.pi if ii != jj else 0.
            assert_allclose(_angle_between_quats(a, b), expected, atol=1e-5)
示例#4
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def test_quaternions():
    """Test quaternion calculations
    """
    rots = [np.eye(3)]
    for fname in [test_fif_fname, ctf_fname, hp_fif_fname]:
        rots += [read_info(fname)['dev_head_t']['trans'][:3, :3]]
    # nasty numerical cases
    rots += [
        np.array([
            [-0.99978541, -0.01873462, -0.00898756],
            [-0.01873462, 0.62565561, 0.77987608],
            [-0.00898756, 0.77987608, -0.62587152],
        ])
    ]
    rots += [
        np.array([
            [0.62565561, -0.01873462, 0.77987608],
            [-0.01873462, -0.99978541, -0.00898756],
            [0.77987608, -0.00898756, -0.62587152],
        ])
    ]
    rots += [
        np.array([
            [-0.99978541, -0.00898756, -0.01873462],
            [-0.00898756, -0.62587152, 0.77987608],
            [-0.01873462, 0.77987608, 0.62565561],
        ])
    ]
    for rot in rots:
        assert_allclose(rot,
                        _quat_to_rot(_rot_to_quat(rot)),
                        rtol=1e-5,
                        atol=1e-5)
        rot = rot[np.newaxis, np.newaxis, :, :]
        assert_allclose(rot,
                        _quat_to_rot(_rot_to_quat(rot)),
                        rtol=1e-5,
                        atol=1e-5)

    # let's make sure our angle function works in some reasonable way
    for ii in range(3):
        for jj in range(3):
            a = np.zeros(3)
            b = np.zeros(3)
            a[ii] = 1.
            b[jj] = 1.
            expected = np.pi if ii != jj else 0.
            assert_allclose(_angle_between_quats(a, b), expected, atol=1e-5)
def test_quaternions():
    """Test quaternion calculations
    """
    rots = [np.eye(3)]
    for fname in [test_fif_fname, ctf_fname, hp_fif_fname]:
        rots += [read_info(fname)['dev_head_t']['trans'][:3, :3]]
    for rot in rots:
        assert_allclose(rot, _quat_to_rot(_rot_to_quat(rot)),
                        rtol=1e-5, atol=1e-5)
        rot = rot[np.newaxis, np.newaxis, :, :]
        assert_allclose(rot, _quat_to_rot(_rot_to_quat(rot)),
                        rtol=1e-5, atol=1e-5)

    # let's make sure our angle function works in some reasonable way
    for ii in range(3):
        for jj in range(3):
            a = np.zeros(3)
            b = np.zeros(3)
            a[ii] = 1.
            b[jj] = 1.
            expected = np.pi if ii != jj else 0.
            assert_allclose(_angle_between_quats(a, b), expected, atol=1e-5)