Exemplos de peak_directions_nl em Python

Exemplo n.º 1

Arquivo: test_peaks.py Projeto: GuillaumeTh/dipy

def test_peak_directions_nl():
    def discrete_eval(sphere):
        return abs(sphere.vertices).sum(-1)

    directions, values = peak_directions_nl(discrete_eval)
    assert_equal(directions.shape, (4, 3))
    assert_array_almost_equal(abs(directions), 1 / np.sqrt(3))
    assert_array_equal(values, abs(directions).sum(-1))

    # Test using a different sphere
    sphere = unit_icosahedron.subdivide(4)
    directions, values = peak_directions_nl(discrete_eval, sphere=sphere)
    assert_equal(directions.shape, (4, 3))
    assert_array_almost_equal(abs(directions), 1 / np.sqrt(3))
    assert_array_equal(values, abs(directions).sum(-1))

    # Test the relative_peak_threshold
    def discrete_eval(sphere):
        A = abs(sphere.vertices).sum(-1)
        x, y, z = sphere.vertices.T
        B = 1 + (x * z > 0) + 2 * (y * z > 0)
        return A * B

    directions, values = peak_directions_nl(discrete_eval, .01)
    assert_equal(directions.shape, (4, 3))

    directions, values = peak_directions_nl(discrete_eval, .3)
    assert_equal(directions.shape, (3, 3))

    directions, values = peak_directions_nl(discrete_eval, .6)
    assert_equal(directions.shape, (2, 3))

    directions, values = peak_directions_nl(discrete_eval, .8)
    assert_equal(directions.shape, (1, 3))
    assert_almost_equal(values, 4 * 3 / np.sqrt(3))

    # Test odfs with large areas of zero
    def discrete_eval(sphere):
        A = abs(sphere.vertices).sum(-1)
        x, y, z = sphere.vertices.T
        B = (x * z > 0) + 2 * (y * z > 0)
        return A * B

    directions, values = peak_directions_nl(discrete_eval, 0.)
    assert_equal(directions.shape, (3, 3))

    directions, values = peak_directions_nl(discrete_eval, .6)
    assert_equal(directions.shape, (2, 3))

    directions, values = peak_directions_nl(discrete_eval, .8)
    assert_equal(directions.shape, (1, 3))
    assert_almost_equal(values, 3 * 3 / np.sqrt(3))

Exemplo n.º 2

Arquivo: test_peaks.py Projeto: swati-malik/dipy

def test_peak_directions_nl():
    def discrete_eval(sphere):
        return abs(sphere.vertices).sum(-1)

    directions, values = peak_directions_nl(discrete_eval)
    assert_equal(directions.shape, (4, 3))
    assert_array_almost_equal(abs(directions), 1 / np.sqrt(3))
    assert_array_equal(values, abs(directions).sum(-1))

    # Test using a different sphere
    sphere = unit_icosahedron.subdivide(4)
    directions, values = peak_directions_nl(discrete_eval, sphere=sphere)
    assert_equal(directions.shape, (4, 3))
    assert_array_almost_equal(abs(directions), 1 / np.sqrt(3))
    assert_array_equal(values, abs(directions).sum(-1))

    # Test the relative_peak_threshold
    def discrete_eval(sphere):
        A = abs(sphere.vertices).sum(-1)
        x, y, z = sphere.vertices.T
        B = 1 + (x * z > 0) + 2 * (y * z > 0)
        return A * B

    directions, values = peak_directions_nl(discrete_eval, .01)
    assert_equal(directions.shape, (4, 3))

    directions, values = peak_directions_nl(discrete_eval, .3)
    assert_equal(directions.shape, (3, 3))

    directions, values = peak_directions_nl(discrete_eval, .6)
    assert_equal(directions.shape, (2, 3))

    directions, values = peak_directions_nl(discrete_eval, .8)
    assert_equal(directions.shape, (1, 3))
    assert_almost_equal(values, 4 * 3 / np.sqrt(3))

    # Test odfs with large areas of zero
    def discrete_eval(sphere):
        A = abs(sphere.vertices).sum(-1)
        x, y, z = sphere.vertices.T
        B = (x * z > 0) + 2 * (y * z > 0)
        return A * B

    directions, values = peak_directions_nl(discrete_eval, 0.)
    assert_equal(directions.shape, (3, 3))

    directions, values = peak_directions_nl(discrete_eval, .6)
    assert_equal(directions.shape, (2, 3))

    directions, values = peak_directions_nl(discrete_eval, .8)
    assert_equal(directions.shape, (1, 3))
    assert_almost_equal(values, 3 * 3 / np.sqrt(3))