AutoAndroidController/python/Lib/site-packages/sympy/physics/mechanics/tests/test_wrapping_geometry.py

"""Tests for the ``sympy.physics.mechanics.wrapping_geometry.py`` module."""

import pytest

from sympy import (
    Integer,
    Rational,
    S,
    Symbol,
    acos,
    cos,
    pi,
    sin,
    sqrt,
)
from sympy.core.relational import Eq
from sympy.physics.mechanics import (
    Point,
    ReferenceFrame,
    WrappingCylinder,
    WrappingSphere,
    dynamicsymbols,
)
from sympy.simplify.simplify import simplify


r = Symbol('r', positive=True)
x = Symbol('x')
q = dynamicsymbols('q')
N = ReferenceFrame('N')


class TestWrappingSphere:

    @staticmethod
    def test_valid_constructor():
        r = Symbol('r', positive=True)
        pO = Point('pO')
        sphere = WrappingSphere(r, pO)
        assert isinstance(sphere, WrappingSphere)
        assert hasattr(sphere, 'radius')
        assert sphere.radius == r
        assert hasattr(sphere, 'point')
        assert sphere.point == pO

    @staticmethod
    @pytest.mark.parametrize('position', [S.Zero, Integer(2)*r*N.x])
    def test_geodesic_length_point_not_on_surface_invalid(position):
        r = Symbol('r', positive=True)
        pO = Point('pO')
        sphere = WrappingSphere(r, pO)

        p1 = Point('p1')
        p1.set_pos(pO, position)
        p2 = Point('p2')
        p2.set_pos(pO, position)

        error_msg = r'point .* does not lie on the surface of'
        with pytest.raises(ValueError, match=error_msg):
            sphere.geodesic_length(p1, p2)

    @staticmethod
    @pytest.mark.parametrize(
        'position_1, position_2, expected',
        [
            (r*N.x, r*N.x, S.Zero),
            (r*N.x, r*N.y, S.Half*pi*r),
            (r*N.x, r*-N.x, pi*r),
            (r*-N.x, r*N.x, pi*r),
            (r*N.x, r*sqrt(2)*S.Half*(N.x + N.y), Rational(1, 4)*pi*r),
            (
                r*sqrt(2)*S.Half*(N.x + N.y),
                r*sqrt(3)*Rational(1, 3)*(N.x + N.y + N.z),
                r*acos(sqrt(6)*Rational(1, 3)),
            ),
        ]
    )
    def test_geodesic_length(position_1, position_2, expected):
        r = Symbol('r', positive=True)
        pO = Point('pO')
        sphere = WrappingSphere(r, pO)

        p1 = Point('p1')
        p1.set_pos(pO, position_1)
        p2 = Point('p2')
        p2.set_pos(pO, position_2)

        assert simplify(Eq(sphere.geodesic_length(p1, p2), expected))

    @staticmethod
    @pytest.mark.parametrize(
        'position_1, position_2, vector_1, vector_2',
        [
            (r * N.x, r * N.y, N.y, N.x),
            (r * N.x, -r * N.y, -N.y, N.x),
            (
                r * N.y,
                sqrt(2)/2 * r * N.x - sqrt(2)/2 * r * N.y,
                N.x,
                sqrt(2)/2 * N.x + sqrt(2)/2 * N.y,
            ),
            (
                r * N.x,
                r / 2 * N.x + sqrt(3)/2 * r * N.y,
                N.y,
                sqrt(3)/2 * N.x - 1/2 * N.y,
            ),
            (
                r * N.x,
                sqrt(2)/2 * r * N.x + sqrt(2)/2 * r * N.y,
                N.y,
                sqrt(2)/2 * N.x - sqrt(2)/2 * N.y,
            ),
        ]
    )
    def test_geodesic_end_vectors(position_1, position_2, vector_1, vector_2):
        r = Symbol('r', positive=True)
        pO = Point('pO')
        sphere = WrappingSphere(r, pO)

        p1 = Point('p1')
        p1.set_pos(pO, position_1)
        p2 = Point('p2')
        p2.set_pos(pO, position_2)

        expected = (vector_1, vector_2)

        assert sphere.geodesic_end_vectors(p1, p2) == expected

    @staticmethod
    @pytest.mark.parametrize(
        'position',
        [r * N.x, r * cos(q) * N.x + r * sin(q) * N.y]
    )
    def test_geodesic_end_vectors_invalid_coincident(position):
        r = Symbol('r', positive=True)
        pO = Point('pO')
        sphere = WrappingSphere(r, pO)

        p1 = Point('p1')
        p1.set_pos(pO, position)
        p2 = Point('p2')
        p2.set_pos(pO, position)

        with pytest.raises(ValueError):
            _ = sphere.geodesic_end_vectors(p1, p2)

    @staticmethod
    @pytest.mark.parametrize(
        'position_1, position_2',
        [
            (r * N.x, -r * N.x),
            (-r * N.y, r * N.y),
            (
                r * cos(q) * N.x + r * sin(q) * N.y,
                -r * cos(q) * N.x - r * sin(q) * N.y,
            )
        ]
    )
    def test_geodesic_end_vectors_invalid_diametrically_opposite(
        position_1,
        position_2,
    ):
        r = Symbol('r', positive=True)
        pO = Point('pO')
        sphere = WrappingSphere(r, pO)

        p1 = Point('p1')
        p1.set_pos(pO, position_1)
        p2 = Point('p2')
        p2.set_pos(pO, position_2)

        with pytest.raises(ValueError):
            _ = sphere.geodesic_end_vectors(p1, p2)


class TestWrappingCylinder:

    @staticmethod
    def test_valid_constructor():
        N = ReferenceFrame('N')
        r = Symbol('r', positive=True)
        pO = Point('pO')
        cylinder = WrappingCylinder(r, pO, N.x)
        assert isinstance(cylinder, WrappingCylinder)
        assert hasattr(cylinder, 'radius')
        assert cylinder.radius == r
        assert hasattr(cylinder, 'point')
        assert cylinder.point == pO
        assert hasattr(cylinder, 'axis')
        assert cylinder.axis == N.x

    @staticmethod
    @pytest.mark.parametrize(
        'position, expected',
        [
            (S.Zero, False),
            (r*N.y, True),
            (r*N.z, True),
            (r*(N.y + N.z).normalize(), True),
            (Integer(2)*r*N.y, False),
            (r*(N.x + N.y), True),
            (r*(Integer(2)*N.x + N.y), True),
            (Integer(2)*N.x + r*(Integer(2)*N.y + N.z).normalize(), True),
            (r*(cos(q)*N.y + sin(q)*N.z), True)
        ]
    )
    def test_point_is_on_surface(position, expected):
        r = Symbol('r', positive=True)
        pO = Point('pO')
        cylinder = WrappingCylinder(r, pO, N.x)

        p1 = Point('p1')
        p1.set_pos(pO, position)

        assert cylinder.point_on_surface(p1) is expected

    @staticmethod
    @pytest.mark.parametrize('position', [S.Zero, Integer(2)*r*N.y])
    def test_geodesic_length_point_not_on_surface_invalid(position):
        r = Symbol('r', positive=True)
        pO = Point('pO')
        cylinder = WrappingCylinder(r, pO, N.x)

        p1 = Point('p1')
        p1.set_pos(pO, position)
        p2 = Point('p2')
        p2.set_pos(pO, position)

        error_msg = r'point .* does not lie on the surface of'
        with pytest.raises(ValueError, match=error_msg):
            cylinder.geodesic_length(p1, p2)

    @staticmethod
    @pytest.mark.parametrize(
        'axis, position_1, position_2, expected',
        [
            (N.x, r*N.y, r*N.y, S.Zero),
            (N.x, r*N.y, N.x + r*N.y, S.One),
            (N.x, r*N.y, -x*N.x + r*N.y, sqrt(x**2)),
            (-N.x, r*N.y, x*N.x + r*N.y, sqrt(x**2)),
            (N.x, r*N.y, r*N.z, S.Half*pi*sqrt(r**2)),
            (-N.x, r*N.y, r*N.z, Integer(3)*S.Half*pi*sqrt(r**2)),
            (N.x, r*N.z, r*N.y, Integer(3)*S.Half*pi*sqrt(r**2)),
            (-N.x, r*N.z, r*N.y, S.Half*pi*sqrt(r**2)),
            (N.x, r*N.y, r*(cos(q)*N.y + sin(q)*N.z), sqrt(r**2*q**2)),
            (
                -N.x, r*N.y,
                r*(cos(q)*N.y + sin(q)*N.z),
                sqrt(r**2*(Integer(2)*pi - q)**2),
            ),
        ]
    )
    def test_geodesic_length(axis, position_1, position_2, expected):
        r = Symbol('r', positive=True)
        pO = Point('pO')
        cylinder = WrappingCylinder(r, pO, axis)

        p1 = Point('p1')
        p1.set_pos(pO, position_1)
        p2 = Point('p2')
        p2.set_pos(pO, position_2)

        assert simplify(Eq(cylinder.geodesic_length(p1, p2), expected))

    @staticmethod
    @pytest.mark.parametrize(
        'axis, position_1, position_2, vector_1, vector_2',
        [
            (N.z, r * N.x, r * N.y, N.y, N.x),
            (N.z, r * N.x, -r * N.x, N.y, N.y),
            (N.z, -r * N.x, r * N.x, -N.y, -N.y),
            (-N.z, r * N.x, -r * N.x, -N.y, -N.y),
            (-N.z, -r * N.x, r * N.x, N.y, N.y),
            (N.z, r * N.x, -r * N.y, N.y, -N.x),
            (
                N.z,
                r * N.y,
                sqrt(2)/2 * r * N.x - sqrt(2)/2 * r * N.y,
                - N.x,
                - sqrt(2)/2 * N.x - sqrt(2)/2 * N.y,
            ),
            (
                N.z,
                r * N.x,
                r / 2 * N.x + sqrt(3)/2 * r * N.y,
                N.y,
                sqrt(3)/2 * N.x - 1/2 * N.y,
            ),
            (
                N.z,
                r * N.x,
                sqrt(2)/2 * r * N.x + sqrt(2)/2 * r * N.y,
                N.y,
                sqrt(2)/2 * N.x - sqrt(2)/2 * N.y,
            ),
            (
                N.z,
                r * N.x,
                r * N.x + N.z,
                N.z,
                -N.z,
            ),
            (
                N.z,
                r * N.x,
                r * N.y + pi/2 * r * N.z,
                sqrt(2)/2 * N.y + sqrt(2)/2 * N.z,
                sqrt(2)/2 * N.x - sqrt(2)/2 * N.z,
            ),
            (
                N.z,
                r * N.x,
                r * cos(q) * N.x + r * sin(q) * N.y,
                N.y,
                sin(q) * N.x - cos(q) * N.y,
            ),
        ]
    )
    def test_geodesic_end_vectors(
        axis,
        position_1,
        position_2,
        vector_1,
        vector_2,
    ):
        r = Symbol('r', positive=True)
        pO = Point('pO')
        cylinder = WrappingCylinder(r, pO, axis)

        p1 = Point('p1')
        p1.set_pos(pO, position_1)
        p2 = Point('p2')
        p2.set_pos(pO, position_2)

        expected = (vector_1, vector_2)
        end_vectors = tuple(
            end_vector.simplify()
            for end_vector in cylinder.geodesic_end_vectors(p1, p2)
        )

        assert end_vectors == expected

    @staticmethod
    @pytest.mark.parametrize(
        'axis, position',
        [
            (N.z, r * N.x),
            (N.z, r * cos(q) * N.x + r * sin(q) * N.y + N.z),
        ]
    )
    def test_geodesic_end_vectors_invalid_coincident(axis, position):
        r = Symbol('r', positive=True)
        pO = Point('pO')
        cylinder = WrappingCylinder(r, pO, axis)

        p1 = Point('p1')
        p1.set_pos(pO, position)
        p2 = Point('p2')
        p2.set_pos(pO, position)

        with pytest.raises(ValueError):
            _ = cylinder.geodesic_end_vectors(p1, p2)