Example #1
0
File: p144.py Project: icot/euler
def main():

    O = Point(0, 0)
    p0 = Point(0, 10.1)
    p1 = Point(1.4, -9.6)
    m = p0.midpoint(p1)
    X = Line(O, Point(10, 0))
    Y = Line(O, Point(0, 10))

    ellipse = Ellipse(Point(0, 0), 5 , 10)
    sortie = Segment(Point(-0.01, 10), Point(0.01, 10))

    ray = Ray(m, p1)

    reflections = 0
    
    while not sortie.intersection(ray) and reflections < 5:
        targets = ellipse.intersection(ray)
        print " Targets: ", targets
        origin = next_origin(ray.p1, targets)
        tangents = ellipse.tangent_lines(origin)
        if len(tangents) > 1:
            print("Error computing intersection")
            break
        tangent = tangents.pop()
        alpha = next_angle(ray, tangent, (X, Y))
        reflections += 1
        ray = Ray(origin, angle=alpha)
        print "Reflections :", reflections
Example #2
0
def test_director_circle():
    x, y, a, b = symbols('x y a b')
    e = Ellipse((x, y), a, b)
    # the general result
    assert e.director_circle() == Circle((x, y), sqrt(a**2 + b**2))
    # a special case where Ellipse is a Circle
    assert Circle((3, 4), 8).director_circle() == Circle((3, 4), 8*sqrt(2))
Example #3
0
def test_auxiliary_circle():
    x, y, a, b = symbols('x y a b')
    e = Ellipse((x, y), a, b)
    # the general result
    assert e.auxiliary_circle() == Circle((x, y), Max(a, b))
    # a special case where Ellipse is a Circle
    assert Circle((3, 4), 8).auxiliary_circle() == Circle((3, 4), 8)
Example #4
0
def test_reflect():
    b = Symbol('b')
    m = Symbol('m')
    l = Line((0, b), slope=m)
    p = Point(x, y)
    r = p.reflect(l)
    dp = l.perpendicular_segment(p).length
    dr = l.perpendicular_segment(r).length
    assert test_numerically(dp, dr)
    t = Triangle((0, 0), (1, 0), (2, 3))
    assert t.area == -t.reflect(l).area
    e = Ellipse((1, 0), 1, 2)
    assert e.area == -e.reflect(Line((1, 0), slope=0)).area
    assert e.area == -e.reflect(Line((1, 0), slope=oo)).area
    raises(NotImplementedError, lambda: e.reflect(Line((1,0), slope=m)))
    # test entity overrides
    c = Circle((x, y), 3)
    cr = c.reflect(l)
    assert cr == Circle(r, -3)
    assert c.area == -cr.area
    pent = RegularPolygon((1, 2), 1, 5)
    l = Line((0, pi), slope=sqrt(2))
    rpent = pent.reflect(l)
    poly_pent = Polygon(*pent.vertices)
    assert rpent.center == pent.center.reflect(l)
    assert str([w.n(3) for w in rpent.vertices]) == (
        '[Point(-0.586, 4.27), Point(-1.69, 4.66), '
        'Point(-2.41, 3.73), Point(-1.74, 2.76), '
        'Point(-0.616, 3.10)]')
    assert pent.area.equals(-rpent.area)
Example #5
0
def test_ellipse_random_point():
    e3 = Ellipse(Point(0, 0), y1, y1)
    rx, ry = Symbol("rx"), Symbol("ry")
    for ind in xrange(0, 5):
        r = e3.random_point()
        # substitution should give zero*y1**2
        assert e3.equation(rx, ry).subs(zip((rx, ry), r.args)).equals(0)
Example #6
0
def test_ellipse_random_point():
    e3 = Ellipse(Point(0, 0), y1, y1)
    rx, ry = Symbol('rx'), Symbol('ry')
    for ind in xrange(0, 5):
        r = e3.random_point()
        # substitution should give zero*y1**2
        assert e3.equation(rx, ry).subs(zip((rx, ry), r.args)
                                        ).n(3).as_coeff_Mul()[0] < 1e-10
Example #7
0
def test_ellipse_random_point():
    y1 = Symbol('y1', real=True)
    e3 = Ellipse(Point(0, 0), y1, y1)
    rx, ry = Symbol('rx'), Symbol('ry')
    for ind in range(0, 5):
        r = e3.random_point()
        # substitution should give zero*y1**2
        assert e3.equation(rx, ry).subs(zip((rx, ry), r.args)).equals(0)
Example #8
0
def test_second_moment_of_area():
    x, y = symbols('x, y')
    e = Ellipse(Point(0, 0), 5, 4)
    I_yy = 2*4*integrate(sqrt(25 - x**2)*x**2, (x, -5, 5))/5
    I_xx = 2*5*integrate(sqrt(16 - y**2)*y**2, (y, -4, 4))/4
    Y = 3*sqrt(1 - x**2/5**2)
    I_xy = integrate(integrate(y, (y, -Y, Y))*x, (x, -5, 5))
    assert I_yy == e.second_moment_of_area()[1]
    assert I_xx == e.second_moment_of_area()[0]
    assert I_xy == e.second_moment_of_area()[2]
Example #9
0
def test_reflect():
    b = Symbol('b')
    m = Symbol('m')
    l = Line((0, b), slope=m)
    t1 = Triangle((0, 0), (1, 0), (2, 3))
    assert t1.area == -t1.reflect(l).area
    e = Ellipse((1, 0), 1, 2)
    assert e.area == -e.reflect(Line((1, 0), slope=0)).area
    assert e.area == -e.reflect(Line((1, 0), slope=oo)).area
    raises(NotImplementedError, lambda: e.reflect(Line((1, 0), slope=m)))
Example #10
0
def test_ellipse_equation_using_slope():
    from sympy.abc import x, y

    e1 = Ellipse(Point(1, 0), 3, 2)
    assert str(e1.equation(_slope=1)) == str((-x + y + 1)**2/8 + (x + y - 1)**2/18 - 1)

    e2 = Ellipse(Point(0, 0), 4, 1)
    assert str(e2.equation(_slope=1)) == str((-x + y)**2/2 + (x + y)**2/32 - 1)

    e3 = Ellipse(Point(1, 5), 6, 2)
    assert str(e3.equation(_slope=2)) == str((-2*x + y - 3)**2/20 + (x + 2*y - 11)**2/180 - 1)
Example #11
0
def test_polygon():
    x = Symbol('x', real=True)
    y = Symbol('y', real=True)
    x1 = Symbol('x1', real=True)
    half = Rational(1, 2)
    a, b, c = Point(0, 0), Point(2, 0), Point(3, 3)
    t = Triangle(a, b, c)
    assert Polygon(a, Point(1, 0), b, c) == t
    assert Polygon(Point(1, 0), b, c, a) == t
    assert Polygon(b, c, a, Point(1, 0)) == t
    # 2 "remove folded" tests
    assert Polygon(a, Point(3, 0), b, c) == t
    assert Polygon(a, b, Point(3, -1), b, c) == t
    # remove multiple collinear points
    assert Polygon(Point(-4, 15), Point(-11, 15), Point(-15, 15),
        Point(-15, 33/5), Point(-15, -87/10), Point(-15, -15),
        Point(-42/5, -15), Point(-2, -15), Point(7, -15), Point(15, -15),
        Point(15, -3), Point(15, 10), Point(15, 15)) == \
        Polygon(Point(-15,-15), Point(15,-15), Point(15,15), Point(-15,15))

    p1 = Polygon(Point(0, 0), Point(3, -1), Point(6, 0), Point(4, 5),
                 Point(2, 3), Point(0, 3))
    p2 = Polygon(Point(6, 0), Point(3, -1), Point(0, 0), Point(0, 3),
                 Point(2, 3), Point(4, 5))
    p3 = Polygon(Point(0, 0), Point(3, 0), Point(5, 2), Point(4, 4))
    p4 = Polygon(Point(0, 0), Point(4, 4), Point(5, 2), Point(3, 0))
    p5 = Polygon(Point(0, 0), Point(4, 4), Point(0, 4))
    p6 = Polygon(Point(-11, 1), Point(-9, 6.6), Point(-4, -3),
                 Point(-8.4, -8.7))
    r = Ray(Point(-9, 6.6), Point(-9, 5.5))
    #
    # General polygon
    #
    assert p1 == p2
    assert len(p1.args) == 6
    assert len(p1.sides) == 6
    assert p1.perimeter == 5 + 2 * sqrt(10) + sqrt(29) + sqrt(8)
    assert p1.area == 22
    assert not p1.is_convex()
    assert Polygon((-1, 1), (2, -1), (2, 1), (-1, -1),
                   (3, 0)).is_convex() is False
    # ensure convex for both CW and CCW point specification
    assert p3.is_convex()
    assert p4.is_convex()
    dict5 = p5.angles
    assert dict5[Point(0, 0)] == pi / 4
    assert dict5[Point(0, 4)] == pi / 2
    assert p5.encloses_point(Point(x, y)) is None
    assert p5.encloses_point(Point(1, 3))
    assert p5.encloses_point(Point(0, 0)) is False
    assert p5.encloses_point(Point(4, 0)) is False
    assert p1.encloses(Circle(Point(2.5, 2.5), 5)) is False
    assert p1.encloses(Ellipse(Point(2.5, 2), 5, 6)) is False
    p5.plot_interval('x') == [x, 0, 1]
    assert p5.distance(Polygon(Point(10, 10), Point(14, 14),
                               Point(10, 14))) == 6 * sqrt(2)
    assert p5.distance(
        Polygon(Point(1, 8), Point(5, 8), Point(8, 12), Point(1, 12))) == 4
    warnings.filterwarnings(
        "error", message="Polygons may intersect producing erroneous output")
    raises(
        UserWarning,
        lambda: Polygon(Point(0, 0), Point(1, 0), Point(1, 1)).distance(
            Polygon(Point(0, 0), Point(0, 1), Point(1, 1))))
    warnings.filterwarnings(
        "ignore", message="Polygons may intersect producing erroneous output")
    assert hash(p5) == hash(Polygon(Point(0, 0), Point(4, 4), Point(0, 4)))
    assert p5 == Polygon(Point(4, 4), Point(0, 4), Point(0, 0))
    assert Polygon(Point(4, 4), Point(0, 4), Point(0, 0)) in p5
    assert p5 != Point(0, 4)
    assert Point(0, 1) in p5
    assert p5.arbitrary_point('t').subs(Symbol('t', real=True), 0) == \
        Point(0, 0)
    raises(
        ValueError, lambda: Polygon(Point(x, 0), Point(0, y), Point(x, y)).
        arbitrary_point('x'))
    assert p6.intersection(r) == [Point(-9, -84 / 13), Point(-9, 33 / 5)]
    #
    # Regular polygon
    #
    p1 = RegularPolygon(Point(0, 0), 10, 5)
    p2 = RegularPolygon(Point(0, 0), 5, 5)
    raises(GeometryError,
           lambda: RegularPolygon(Point(0, 0), Point(0, 1), Point(1, 1)))
    raises(GeometryError, lambda: RegularPolygon(Point(0, 0), 1, 2))
    raises(ValueError, lambda: RegularPolygon(Point(0, 0), 1, 2.5))

    assert p1 != p2
    assert p1.interior_angle == 3 * pi / 5
    assert p1.exterior_angle == 2 * pi / 5
    assert p2.apothem == 5 * cos(pi / 5)
    assert p2.circumcenter == p1.circumcenter == Point(0, 0)
    assert p1.circumradius == p1.radius == 10
    assert p2.circumcircle == Circle(Point(0, 0), 5)
    assert p2.incircle == Circle(Point(0, 0), p2.apothem)
    assert p2.inradius == p2.apothem == (5 * (1 + sqrt(5)) / 4)
    p2.spin(pi / 10)
    dict1 = p2.angles
    assert dict1[Point(0, 5)] == 3 * pi / 5
    assert p1.is_convex()
    assert p1.rotation == 0
    assert p1.encloses_point(Point(0, 0))
    assert p1.encloses_point(Point(11, 0)) is False
    assert p2.encloses_point(Point(0, 4.9))
    p1.spin(pi / 3)
    assert p1.rotation == pi / 3
    assert p1.vertices[0] == Point(5, 5 * sqrt(3))
    for var in p1.args:
        if isinstance(var, Point):
            assert var == Point(0, 0)
        else:
            assert var == 5 or var == 10 or var == pi / 3
    assert p1 != Point(0, 0)
    assert p1 != p5

    # while spin works in place (notice that rotation is 2pi/3 below)
    # rotate returns a new object
    p1_old = p1
    assert p1.rotate(pi / 3) == RegularPolygon(Point(0, 0), 10, 5, 2 * pi / 3)
    assert p1 == p1_old

    assert p1.area == (-250 * sqrt(5) + 1250) / (4 * tan(pi / 5))
    assert p1.length == 20 * sqrt(-sqrt(5) / 8 + 5 / 8)
    assert p1.scale(2, 2) == \
        RegularPolygon(p1.center, p1.radius*2, p1._n, p1.rotation)
    assert RegularPolygon((0, 0), 1, 4).scale(2, 3) == \
        Polygon(Point(2, 0), Point(0, 3), Point(-2, 0), Point(0, -3))

    assert repr(p1) == str(p1)

    #
    # Angles
    #
    angles = p4.angles
    assert feq(angles[Point(0, 0)].evalf(), Float("0.7853981633974483"))
    assert feq(angles[Point(4, 4)].evalf(), Float("1.2490457723982544"))
    assert feq(angles[Point(5, 2)].evalf(), Float("1.8925468811915388"))
    assert feq(angles[Point(3, 0)].evalf(), Float("2.3561944901923449"))

    angles = p3.angles
    assert feq(angles[Point(0, 0)].evalf(), Float("0.7853981633974483"))
    assert feq(angles[Point(4, 4)].evalf(), Float("1.2490457723982544"))
    assert feq(angles[Point(5, 2)].evalf(), Float("1.8925468811915388"))
    assert feq(angles[Point(3, 0)].evalf(), Float("2.3561944901923449"))

    #
    # Triangle
    #
    p1 = Point(0, 0)
    p2 = Point(5, 0)
    p3 = Point(0, 5)
    t1 = Triangle(p1, p2, p3)
    t2 = Triangle(p1, p2, Point(Rational(5, 2), sqrt(Rational(75, 4))))
    t3 = Triangle(p1, Point(x1, 0), Point(0, x1))
    s1 = t1.sides
    assert Triangle(p1, p2, p1) == Polygon(p1, p2, p1) == Segment(p1, p2)
    raises(GeometryError, lambda: Triangle(Point(0, 0)))

    # Basic stuff
    assert Triangle(p1, p1, p1) == p1
    assert Triangle(p2, p2 * 2, p2 * 3) == Segment(p2, p2 * 3)
    assert t1.area == Rational(25, 2)
    assert t1.is_right()
    assert t2.is_right() is False
    assert t3.is_right()
    assert p1 in t1
    assert t1.sides[0] in t1
    assert Segment((0, 0), (1, 0)) in t1
    assert Point(5, 5) not in t2
    assert t1.is_convex()
    assert feq(t1.angles[p1].evalf(), pi.evalf() / 2)

    assert t1.is_equilateral() is False
    assert t2.is_equilateral()
    assert t3.is_equilateral() is False
    assert are_similar(t1, t2) is False
    assert are_similar(t1, t3)
    assert are_similar(t2, t3) is False
    assert t1.is_similar(Point(0, 0)) is False

    # Bisectors
    bisectors = t1.bisectors()
    assert bisectors[p1] == Segment(p1, Point(Rational(5, 2), Rational(5, 2)))
    ic = (250 - 125 * sqrt(2)) / 50
    assert t1.incenter == Point(ic, ic)

    # Inradius
    assert t1.inradius == t1.incircle.radius == 5 - 5 * sqrt(2) / 2
    assert t2.inradius == t2.incircle.radius == 5 * sqrt(3) / 6
    assert t3.inradius == t3.incircle.radius == x1**2 / (
        (2 + sqrt(2)) * Abs(x1))

    # Exradius
    assert t1.exradii[t1.sides[2]] == 5 * sqrt(2) / 2

    # Circumcircle
    assert t1.circumcircle.center == Point(2.5, 2.5)

    # Medians + Centroid
    m = t1.medians
    assert t1.centroid == Point(Rational(5, 3), Rational(5, 3))
    assert m[p1] == Segment(p1, Point(Rational(5, 2), Rational(5, 2)))
    assert t3.medians[p1] == Segment(p1, Point(x1 / 2, x1 / 2))
    assert intersection(m[p1], m[p2], m[p3]) == [t1.centroid]
    assert t1.medial == Triangle(Point(2.5, 0), Point(0, 2.5), Point(2.5, 2.5))

    # Nine-point circle
    assert t1.nine_point_circle == Circle(Point(2.5, 0), Point(0, 2.5),
                                          Point(2.5, 2.5))
    assert t1.nine_point_circle == Circle(Point(0, 0), Point(0, 2.5),
                                          Point(2.5, 2.5))

    # Perpendicular
    altitudes = t1.altitudes
    assert altitudes[p1] == Segment(p1, Point(Rational(5, 2), Rational(5, 2)))
    assert altitudes[p2].equals(s1[0])
    assert altitudes[p3] == s1[2]
    assert t1.orthocenter == p1
    t = S('''Triangle(
    Point(100080156402737/5000000000000, 79782624633431/500000000000),
    Point(39223884078253/2000000000000, 156345163124289/1000000000000),
    Point(31241359188437/1250000000000, 338338270939941/1000000000000000))''')
    assert t.orthocenter == S(
        '''Point(-780660869050599840216997'''
        '''79471538701955848721853/80368430960602242240789074233100000000000000,'''
        '''20151573611150265741278060334545897615974257/16073686192120448448157'''
        '''8148466200000000000)''')

    # Ensure
    assert len(intersection(*bisectors.values())) == 1
    assert len(intersection(*altitudes.values())) == 1
    assert len(intersection(*m.values())) == 1

    # Distance
    p1 = Polygon(Point(0, 0), Point(1, 0), Point(1, 1), Point(0, 1))
    p2 = Polygon(Point(0,
                       Rational(5) / 4), Point(1,
                                               Rational(5) / 4),
                 Point(1,
                       Rational(9) / 4), Point(0,
                                               Rational(9) / 4))
    p3 = Polygon(Point(1, 2), Point(2, 2), Point(2, 1))
    p4 = Polygon(Point(1, 1), Point(Rational(6) / 5, 1),
                 Point(1,
                       Rational(6) / 5))
    pt1 = Point(half, half)
    pt2 = Point(1, 1)
    '''Polygon to Point'''
    assert p1.distance(pt1) == half
    assert p1.distance(pt2) == 0
    assert p2.distance(pt1) == Rational(3) / 4
    assert p3.distance(pt2) == sqrt(2) / 2
    '''Polygon to Polygon'''
    # p1.distance(p2) emits a warning
    # First, test the warning
    warnings.filterwarnings(
        "error", message="Polygons may intersect producing erroneous output")
    raises(UserWarning, lambda: p1.distance(p2))
    # now test the actual output
    warnings.filterwarnings(
        "ignore", message="Polygons may intersect producing erroneous output")
    assert p1.distance(p2) == half / 2

    assert p1.distance(p3) == sqrt(2) / 2
    assert p3.distance(p4) == (sqrt(2) / 2 - sqrt(Rational(2) / 25) / 2)
Example #12
0
def test_ellipse_intersection_fail():
    # these need the upgrade to the solver; when this works, move
    # these lines to the FAILING ELLIPSE INTERSECTION GOES HERE line in test_ellipse above.
    e1 = Ellipse(Point(0, 0), 5, 10)
    e2 = Ellipse(Point(2, 1), 4, 8)
    assert e1.intersection(e2) # when this no longer fails, supply the answer
Example #13
0
def test_ellipse_random_point():
    e3 = Ellipse(Point(0, 0), y1, y1)
    for ind in xrange(0, 5):
        assert e3.random_point() in e3
Example #14
0
def test_ellipse_geom():
    x = Symbol('x', real=True)
    y = Symbol('y', real=True)
    t = Symbol('t', real=True)
    y1 = Symbol('y1', real=True)
    half = Rational(1, 2)
    p1 = Point(0, 0)
    p2 = Point(1, 1)
    p4 = Point(0, 1)

    e1 = Ellipse(p1, 1, 1)
    e2 = Ellipse(p2, half, 1)
    e3 = Ellipse(p1, y1, y1)
    c1 = Circle(p1, 1)
    c2 = Circle(p2, 1)
    c3 = Circle(Point(sqrt(2), sqrt(2)), 1)
    l1 = Line(p1, p2)

    # Test creation with three points
    cen, rad = Point(3*half, 2), 5*half
    assert Circle(Point(0, 0), Point(3, 0), Point(0, 4)) == Circle(cen, rad)
    assert Circle(Point(0, 0), Point(1, 1), Point(2, 2)) == Segment2D(Point2D(0, 0), Point2D(2, 2))

    raises(ValueError, lambda: Ellipse(None, None, None, 1))
    raises(GeometryError, lambda: Circle(Point(0, 0)))

    # Basic Stuff
    assert Ellipse(None, 1, 1).center == Point(0, 0)
    assert e1 == c1
    assert e1 != e2
    assert e1 != l1
    assert p4 in e1
    assert p2 not in e2
    assert e1.area == pi
    assert e2.area == pi/2
    assert e3.area == pi*y1*abs(y1)
    assert c1.area == e1.area
    assert c1.circumference == e1.circumference
    assert e3.circumference == 2*pi*y1
    assert e1.plot_interval() == e2.plot_interval() == [t, -pi, pi]
    assert e1.plot_interval(x) == e2.plot_interval(x) == [x, -pi, pi]

    assert c1.minor == 1
    assert c1.major == 1
    assert c1.hradius == 1
    assert c1.vradius == 1

    assert Ellipse((1, 1), 0, 0) == Point(1, 1)
    assert Ellipse((1, 1), 1, 0) == Segment(Point(0, 1), Point(2, 1))
    assert Ellipse((1, 1), 0, 1) == Segment(Point(1, 0), Point(1, 2))

    # Private Functions
    assert hash(c1) == hash(Circle(Point(1, 0), Point(0, 1), Point(0, -1)))
    assert c1 in e1
    assert (Line(p1, p2) in e1) is False
    assert e1.__cmp__(e1) == 0
    assert e1.__cmp__(Point(0, 0)) > 0

    # Encloses
    assert e1.encloses(Segment(Point(-0.5, -0.5), Point(0.5, 0.5))) is True
    assert e1.encloses(Line(p1, p2)) is False
    assert e1.encloses(Ray(p1, p2)) is False
    assert e1.encloses(e1) is False
    assert e1.encloses(
        Polygon(Point(-0.5, -0.5), Point(-0.5, 0.5), Point(0.5, 0.5))) is True
    assert e1.encloses(RegularPolygon(p1, 0.5, 3)) is True
    assert e1.encloses(RegularPolygon(p1, 5, 3)) is False
    assert e1.encloses(RegularPolygon(p2, 5, 3)) is False

    assert e2.arbitrary_point() in e2

    # Foci
    f1, f2 = Point(sqrt(12), 0), Point(-sqrt(12), 0)
    ef = Ellipse(Point(0, 0), 4, 2)
    assert ef.foci in [(f1, f2), (f2, f1)]

    # Tangents
    v = sqrt(2) / 2
    p1_1 = Point(v, v)
    p1_2 = p2 + Point(half, 0)
    p1_3 = p2 + Point(0, 1)
    assert e1.tangent_lines(p4) == c1.tangent_lines(p4)
    assert e2.tangent_lines(p1_2) == [Line(Point(S(3)/2, 1), Point(S(3)/2, S(1)/2))]
    assert e2.tangent_lines(p1_3) == [Line(Point(1, 2), Point(S(5)/4, 2))]
    assert c1.tangent_lines(p1_1) != [Line(p1_1, Point(0, sqrt(2)))]
    assert c1.tangent_lines(p1) == []
    assert e2.is_tangent(Line(p1_2, p2 + Point(half, 1)))
    assert e2.is_tangent(Line(p1_3, p2 + Point(half, 1)))
    assert c1.is_tangent(Line(p1_1, Point(0, sqrt(2))))
    assert e1.is_tangent(Line(Point(0, 0), Point(1, 1))) is False
    assert c1.is_tangent(e1) is True
    assert c1.is_tangent(Ellipse(Point(2, 0), 1, 1)) is True
    assert c1.is_tangent(
        Polygon(Point(1, 1), Point(1, -1), Point(2, 0))) is True
    assert c1.is_tangent(
        Polygon(Point(1, 1), Point(1, 0), Point(2, 0))) is False
    assert Circle(Point(5, 5), 3).is_tangent(Circle(Point(0, 5), 1)) is False

    assert Ellipse(Point(5, 5), 2, 1).tangent_lines(Point(0, 0)) == \
        [Line(Point(0, 0), Point(S(77)/25, S(132)/25)),
     Line(Point(0, 0), Point(S(33)/5, S(22)/5))]
    assert Ellipse(Point(5, 5), 2, 1).tangent_lines(Point(3, 4)) == \
        [Line(Point(3, 4), Point(4, 4)), Line(Point(3, 4), Point(3, 5))]
    assert Circle(Point(5, 5), 2).tangent_lines(Point(3, 3)) == \
        [Line(Point(3, 3), Point(4, 3)), Line(Point(3, 3), Point(3, 4))]
    assert Circle(Point(5, 5), 2).tangent_lines(Point(5 - 2*sqrt(2), 5)) == \
        [Line(Point(5 - 2*sqrt(2), 5), Point(5 - sqrt(2), 5 - sqrt(2))),
     Line(Point(5 - 2*sqrt(2), 5), Point(5 - sqrt(2), 5 + sqrt(2))), ]

    # for numerical calculations, we shouldn't demand exact equality,
    # so only test up to the desired precision
    def lines_close(l1, l2, prec):
        """ tests whether l1 and 12 are within 10**(-prec)
        of each other """
        return abs(l1.p1 - l2.p1) < 10**(-prec) and abs(l1.p2 - l2.p2) < 10**(-prec)
    def line_list_close(ll1, ll2, prec):
        return all(lines_close(l1, l2, prec) for l1, l2 in zip(ll1, ll2))

    e = Ellipse(Point(0, 0), 2, 1)
    assert e.normal_lines(Point(0, 0)) == \
        [Line(Point(0, 0), Point(0, 1)), Line(Point(0, 0), Point(1, 0))]
    assert e.normal_lines(Point(1, 0)) == \
        [Line(Point(0, 0), Point(1, 0))]
    assert e.normal_lines((0, 1)) == \
        [Line(Point(0, 0), Point(0, 1))]
    assert line_list_close(e.normal_lines(Point(1, 1), 2), [
        Line(Point(-S(51)/26, -S(1)/5), Point(-S(25)/26, S(17)/83)),
        Line(Point(S(28)/29, -S(7)/8), Point(S(57)/29, -S(9)/2))], 2)
    # test the failure of Poly.intervals and checks a point on the boundary
    p = Point(sqrt(3), S.Half)
    assert p in e
    assert line_list_close(e.normal_lines(p, 2), [
        Line(Point(-S(341)/171, -S(1)/13), Point(-S(170)/171, S(5)/64)),
        Line(Point(S(26)/15, -S(1)/2), Point(S(41)/15, -S(43)/26))], 2)
    # be sure to use the slope that isn't undefined on boundary
    e = Ellipse((0, 0), 2, 2*sqrt(3)/3)
    assert line_list_close(e.normal_lines((1, 1), 2), [
        Line(Point(-S(64)/33, -S(20)/71), Point(-S(31)/33, S(2)/13)),
        Line(Point(1, -1), Point(2, -4))], 2)
    # general ellipse fails except under certain conditions
    e = Ellipse((0, 0), x, 1)
    assert e.normal_lines((x + 1, 0)) == [Line(Point(0, 0), Point(1, 0))]
    raises(NotImplementedError, lambda: e.normal_lines((x + 1, 1)))
    # Properties
    major = 3
    minor = 1
    e4 = Ellipse(p2, minor, major)
    assert e4.focus_distance == sqrt(major**2 - minor**2)
    ecc = e4.focus_distance / major
    assert e4.eccentricity == ecc
    assert e4.periapsis == major*(1 - ecc)
    assert e4.apoapsis == major*(1 + ecc)
    assert e4.semilatus_rectum == major*(1 - ecc ** 2)
    # independent of orientation
    e4 = Ellipse(p2, major, minor)
    assert e4.focus_distance == sqrt(major**2 - minor**2)
    ecc = e4.focus_distance / major
    assert e4.eccentricity == ecc
    assert e4.periapsis == major*(1 - ecc)
    assert e4.apoapsis == major*(1 + ecc)

    # Intersection
    l1 = Line(Point(1, -5), Point(1, 5))
    l2 = Line(Point(-5, -1), Point(5, -1))
    l3 = Line(Point(-1, -1), Point(1, 1))
    l4 = Line(Point(-10, 0), Point(0, 10))
    pts_c1_l3 = [Point(sqrt(2)/2, sqrt(2)/2), Point(-sqrt(2)/2, -sqrt(2)/2)]

    assert intersection(e2, l4) == []
    assert intersection(c1, Point(1, 0)) == [Point(1, 0)]
    assert intersection(c1, l1) == [Point(1, 0)]
    assert intersection(c1, l2) == [Point(0, -1)]
    assert intersection(c1, l3) in [pts_c1_l3, [pts_c1_l3[1], pts_c1_l3[0]]]
    assert intersection(c1, c2) == [Point(0, 1), Point(1, 0)]
    assert intersection(c1, c3) == [Point(sqrt(2)/2, sqrt(2)/2)]
    assert e1.intersection(l1) == [Point(1, 0)]
    assert e2.intersection(l4) == []
    assert e1.intersection(Circle(Point(0, 2), 1)) == [Point(0, 1)]
    assert e1.intersection(Circle(Point(5, 0), 1)) == []
    assert e1.intersection(Ellipse(Point(2, 0), 1, 1)) == [Point(1, 0)]
    assert e1.intersection(Ellipse(Point(5, 0), 1, 1)) == []
    assert e1.intersection(Point(2, 0)) == []
    assert e1.intersection(e1) == e1
    assert intersection(Ellipse(Point(0, 0), 2, 1), Ellipse(Point(3, 0), 1, 2)) == [Point(2, 0)]
    assert intersection(Circle(Point(0, 0), 2), Circle(Point(3, 0), 1)) == [Point(2, 0)]
    assert intersection(Circle(Point(0, 0), 2), Circle(Point(7, 0), 1)) == []
    assert intersection(Ellipse(Point(0, 0), 5, 17), Ellipse(Point(4, 0), 1, 0.2)) == [Point(5, 0)]
    assert intersection(Ellipse(Point(0, 0), 5, 17), Ellipse(Point(4, 0), 0.999, 0.2)) == []
    assert Circle((0, 0), S(1)/2).intersection(
        Triangle((-1, 0), (1, 0), (0, 1))) == [
        Point(-S(1)/2, 0), Point(S(1)/2, 0)]
    raises(TypeError, lambda: intersection(e2, Line((0, 0, 0), (0, 0, 1))))
    raises(TypeError, lambda: intersection(e2, Rational(12)))
    # some special case intersections
    csmall = Circle(p1, 3)
    cbig = Circle(p1, 5)
    cout = Circle(Point(5, 5), 1)
    # one circle inside of another
    assert csmall.intersection(cbig) == []
    # separate circles
    assert csmall.intersection(cout) == []
    # coincident circles
    assert csmall.intersection(csmall) == csmall

    v = sqrt(2)
    t1 = Triangle(Point(0, v), Point(0, -v), Point(v, 0))
    points = intersection(t1, c1)
    assert len(points) == 4
    assert Point(0, 1) in points
    assert Point(0, -1) in points
    assert Point(v/2, v/2) in points
    assert Point(v/2, -v/2) in points

    circ = Circle(Point(0, 0), 5)
    elip = Ellipse(Point(0, 0), 5, 20)
    assert intersection(circ, elip) in \
        [[Point(5, 0), Point(-5, 0)], [Point(-5, 0), Point(5, 0)]]
    assert elip.tangent_lines(Point(0, 0)) == []
    elip = Ellipse(Point(0, 0), 3, 2)
    assert elip.tangent_lines(Point(3, 0)) == \
        [Line(Point(3, 0), Point(3, -12))]

    e1 = Ellipse(Point(0, 0), 5, 10)
    e2 = Ellipse(Point(2, 1), 4, 8)
    a = S(53)/17
    c = 2*sqrt(3991)/17
    ans = [Point(a - c/8, a/2 + c), Point(a + c/8, a/2 - c)]
    assert e1.intersection(e2) == ans
    e2 = Ellipse(Point(x, y), 4, 8)
    c = sqrt(3991)
    ans = [Point(-c/68 + a, 2*c/17 + a/2), Point(c/68 + a, -2*c/17 + a/2)]
    assert [p.subs({x: 2, y:1}) for p in e1.intersection(e2)] == ans

    # Combinations of above
    assert e3.is_tangent(e3.tangent_lines(p1 + Point(y1, 0))[0])

    e = Ellipse((1, 2), 3, 2)
    assert e.tangent_lines(Point(10, 0)) == \
        [Line(Point(10, 0), Point(1, 0)),
        Line(Point(10, 0), Point(S(14)/5, S(18)/5))]

    # encloses_point
    e = Ellipse((0, 0), 1, 2)
    assert e.encloses_point(e.center)
    assert e.encloses_point(e.center + Point(0, e.vradius - Rational(1, 10)))
    assert e.encloses_point(e.center + Point(e.hradius - Rational(1, 10), 0))
    assert e.encloses_point(e.center + Point(e.hradius, 0)) is False
    assert e.encloses_point(
        e.center + Point(e.hradius + Rational(1, 10), 0)) is False
    e = Ellipse((0, 0), 2, 1)
    assert e.encloses_point(e.center)
    assert e.encloses_point(e.center + Point(0, e.vradius - Rational(1, 10)))
    assert e.encloses_point(e.center + Point(e.hradius - Rational(1, 10), 0))
    assert e.encloses_point(e.center + Point(e.hradius, 0)) is False
    assert e.encloses_point(
        e.center + Point(e.hradius + Rational(1, 10), 0)) is False
    assert c1.encloses_point(Point(1, 0)) is False
    assert c1.encloses_point(Point(0.3, 0.4)) is True

    assert e.scale(2, 3) == Ellipse((0, 0), 4, 3)
    assert e.scale(3, 6) == Ellipse((0, 0), 6, 6)
    assert e.rotate(pi) == e
    assert e.rotate(pi, (1, 2)) == Ellipse(Point(2, 4), 2, 1)
    raises(NotImplementedError, lambda: e.rotate(pi/3))

    # Circle rotation tests (Issue #11743)
    # Link - https://github.com/sympy/sympy/issues/11743
    cir = Circle(Point(1, 0), 1)
    assert cir.rotate(pi/2) == Circle(Point(0, 1), 1)
    assert cir.rotate(pi/3) == Circle(Point(S(1)/2, sqrt(3)/2), 1)
    assert cir.rotate(pi/3, Point(1, 0)) == Circle(Point(1, 0), 1)
    assert cir.rotate(pi/3, Point(0, 1)) == Circle(Point(S(1)/2 + sqrt(3)/2, S(1)/2 + sqrt(3)/2), 1)
Example #15
0
def test_parameter_value():
    t = Symbol('t')
    e = Ellipse(Point(0, 0), 3, 5)
    assert e.parameter_value((3, 0), t) == {t: 0}
    raises(ValueError, lambda: e.parameter_value((4, 0), t))
Example #16
0
def test_Geometry():
    sT(Point(0, 0), "Point(Integer(0), Integer(0))")
    sT(Ellipse(Point(0, 0), 5, 1),
       "Ellipse(Point(Integer(0), Integer(0)), Integer(5), Integer(1))")
Example #17
0
def test_section_modulus_and_polar_second_moment_of_area():
    d = Symbol('d', positive=True)
    c = Circle((3, 7), 8)
    assert c.polar_second_moment_of_area() == 2048 * pi
    assert c.section_modulus() == (128 * pi, 128 * pi)
    c = Circle((2, 9), d / 2)
    assert c.polar_second_moment_of_area(
    ) == pi * d**3 * Abs(d) / 64 + pi * d * Abs(d)**3 / 64
    assert c.section_modulus() == (pi * d**3 / S(32), pi * d**3 / S(32))

    a, b = symbols('a, b', positive=True)
    e = Ellipse((4, 6), a, b)
    assert e.section_modulus() == (pi * a * b**2 / S(4), pi * a**2 * b / S(4))
    assert e.polar_second_moment_of_area(
    ) == pi * a**3 * b / S(4) + pi * a * b**3 / S(4)
    e = e.rotate(pi / 2)  # no change in polar and section modulus
    assert e.section_modulus() == (pi * a**2 * b / S(4), pi * a * b**2 / S(4))
    assert e.polar_second_moment_of_area(
    ) == pi * a**3 * b / S(4) + pi * a * b**3 / S(4)

    e = Ellipse((a, b), 2, 6)
    assert e.section_modulus() == (18 * pi, 6 * pi)
    assert e.polar_second_moment_of_area() == 120 * pi
Example #18
0
def test_ellipse_geom():
    p1 = Point(0, 0)
    p2 = Point(1, 1)
    p4 = Point(0, 1)

    e1 = Ellipse(p1, 1, 1)
    e2 = Ellipse(p2, half, 1)
    e3 = Ellipse(p1, y1, y1)
    c1 = Circle(p1, 1)
    c2 = Circle(p2, 1)
    c3 = Circle(Point(sqrt(2), sqrt(2)), 1)

    # Test creation with three points
    cen, rad = Point(3*half, 2), 5*half
    assert Circle(Point(0, 0), Point(3, 0), Point(0, 4)) == Circle(cen, rad)
    raises(
        GeometryError, lambda: Circle(Point(0, 0), Point(1, 1), Point(2, 2)))

    raises(ValueError, lambda: Ellipse(None, None, None, 1))
    raises(GeometryError, lambda: Circle(Point(0, 0)))

    # Basic Stuff
    assert Ellipse(None, 1, 1).center == Point(0, 0)
    assert e1 == c1
    assert e1 != e2
    assert p4 in e1
    assert p2 not in e2
    assert e1.area == pi
    assert e2.area == pi/2
    assert e3.area == pi*y1*abs(y1)
    assert c1.area == e1.area
    assert c1.circumference == e1.circumference
    assert e3.circumference == 2*pi*y1
    assert e1.plot_interval() == e2.plot_interval() == [t, -pi, pi]
    assert e1.plot_interval(x) == e2.plot_interval(x) == [x, -pi, pi]
    assert Ellipse(None, 1, None, 1).circumference == 2*pi
    assert c1.minor == 1
    assert c1.major == 1
    assert c1.hradius == 1
    assert c1.vradius == 1

    # Private Functions
    assert hash(c1) == hash(Circle(Point(1, 0), Point(0, 1), Point(0, -1)))
    assert c1 in e1
    assert (Line(p1, p2) in e1) is False
    assert e1.__cmp__(e1) == 0
    assert e1.__cmp__(Point(0, 0)) > 0

    # Encloses
    assert e1.encloses(Segment(Point(-0.5, -0.5), Point(0.5, 0.5))) is True
    assert e1.encloses(Line(p1, p2)) is False
    assert e1.encloses(Ray(p1, p2)) is False
    assert e1.encloses(e1) is False
    assert e1.encloses(
        Polygon(Point(-0.5, -0.5), Point(-0.5, 0.5), Point(0.5, 0.5))) is True
    assert e1.encloses(RegularPolygon(p1, 0.5, 3)) is True
    assert e1.encloses(RegularPolygon(p1, 5, 3)) is False
    assert e1.encloses(RegularPolygon(p2, 5, 3)) is False

    # with generic symbols, the hradius is assumed to contain the major radius
    M = Symbol('M')
    m = Symbol('m')
    c = Ellipse(p1, M, m).circumference
    _x = c.atoms(Dummy).pop()
    assert c == 4*M*Integral(
        sqrt((1 - _x**2*(M**2 - m**2)/M**2)/(1 - _x**2)), (_x, 0, 1))

    assert e2.arbitrary_point() in e2

    # Foci
    f1, f2 = Point(sqrt(12), 0), Point(-sqrt(12), 0)
    ef = Ellipse(Point(0, 0), 4, 2)
    assert ef.foci in [(f1, f2), (f2, f1)]

    # Tangents
    v = sqrt(2) / 2
    p1_1 = Point(v, v)
    p1_2 = p2 + Point(half, 0)
    p1_3 = p2 + Point(0, 1)
    assert e1.tangent_lines(p4) == c1.tangent_lines(p4)
    assert e2.tangent_lines(p1_2) == [Line(Point(3/2, 1), Point(3/2, 1/2))]
    assert e2.tangent_lines(p1_3) == [Line(Point(1, 2), Point(5/4, 2))]
    assert c1.tangent_lines(p1_1) != [Line(p1_1, Point(0, sqrt(2)))]
    assert c1.tangent_lines(p1) == []
    assert e2.is_tangent(Line(p1_2, p2 + Point(half, 1)))
    assert e2.is_tangent(Line(p1_3, p2 + Point(half, 1)))
    assert c1.is_tangent(Line(p1_1, Point(0, sqrt(2))))
    assert e1.is_tangent(Line(Point(0, 0), Point(1, 1))) is False
    assert c1.is_tangent(e1) is False
    assert c1.is_tangent(Ellipse(Point(2, 0), 1, 1)) is True
    assert c1.is_tangent(
        Polygon(Point(1, 1), Point(1, -1), Point(2, 0))) is True
    assert c1.is_tangent(
        Polygon(Point(1, 1), Point(1, 0), Point(2, 0))) is False
    assert Circle(Point(5, 5), 3).is_tangent(Circle(Point(0, 5), 1)) is False

    assert Ellipse(Point(5, 5), 2, 1).tangent_lines(Point(0, 0)) == \
        [Line(Point(0, 0), Point(77/25, 132/25)),
     Line(Point(0, 0), Point(33/5, 22/5))]
    assert Ellipse(Point(5, 5), 2, 1).tangent_lines(Point(3, 4)) == \
        [Line(Point(3, 4), Point(4, 4)), Line(Point(3, 4), Point(3, 5))]
    assert Circle(Point(5, 5), 2).tangent_lines(Point(3, 3)) == \
        [Line(Point(3, 3), Point(4, 3)), Line(Point(3, 3), Point(3, 4))]
    assert Circle(Point(5, 5), 2).tangent_lines(Point(5 - 2*sqrt(2), 5)) == \
        [Line(Point(5 - 2*sqrt(2), 5), Point(5 - sqrt(2), 5 - sqrt(2))),
     Line(Point(5 - 2*sqrt(2), 5), Point(5 - sqrt(2), 5 + sqrt(2))), ]

    e = Ellipse(Point(0, 0), 2, 1)
    assert e.normal_lines(Point(0, 0)) == \
        [Line(Point(0, 0), Point(0, 1)), Line(Point(0, 0), Point(1, 0))]
    assert e.normal_lines(Point(1, 0)) == \
        [Line(Point(0, 0), Point(1, 0))]
    assert e.normal_lines((0, 1)) == \
        [Line(Point(0, 0), Point(0, 1))]
    assert e.normal_lines(Point(1, 1), 2) == [
        Line(Point(-51/26, -1/5), Point(-25/26, 17/83)),
        Line(Point(28/29, -7/8), Point(57/29, -9/2))]
    # test the failure of Poly.intervals and checks a point on the boundary
    p = Point(sqrt(3), S.Half)
    assert p in e
    assert e.normal_lines(p, 2) == [
        Line(Point(-341/171, -1/13), Point(-170/171, 5/64)),
        Line(Point(26/15, -1/2), Point(41/15, -43/26))]
    # be sure to use the slope that isn't undefined on boundary
    e = Ellipse((0, 0), 2, 2*sqrt(3)/3)
    assert e.normal_lines((1, 1), 2) == [
        Line(Point(-64/33, -20/71), Point(-31/33, 2/13)),
        Line(Point(1, -1), Point(2, -4))]
    # general ellipse fails except under certain conditions
    e = Ellipse((0, 0), x, 1)
    assert e.normal_lines((x + 1, 0)) == [Line(Point(0, 0), Point(1, 0))]
    raises(NotImplementedError, lambda: e.normal_lines((x + 1, 1)))


    # Properties
    major = 3
    minor = 1
    e4 = Ellipse(p2, minor, major)
    assert e4.focus_distance == sqrt(major**2 - minor**2)
    ecc = e4.focus_distance / major
    assert e4.eccentricity == ecc
    assert e4.periapsis == major*(1 - ecc)
    assert e4.apoapsis == major*(1 + ecc)
    # independent of orientation
    e4 = Ellipse(p2, major, minor)
    assert e4.focus_distance == sqrt(major**2 - minor**2)
    ecc = e4.focus_distance / major
    assert e4.eccentricity == ecc
    assert e4.periapsis == major*(1 - ecc)
    assert e4.apoapsis == major*(1 + ecc)

    # Intersection
    l1 = Line(Point(1, -5), Point(1, 5))
    l2 = Line(Point(-5, -1), Point(5, -1))
    l3 = Line(Point(-1, -1), Point(1, 1))
    l4 = Line(Point(-10, 0), Point(0, 10))
    pts_c1_l3 = [Point(sqrt(2)/2, sqrt(2)/2), Point(-sqrt(2)/2, -sqrt(2)/2)]

    assert intersection(e2, l4) == []
    assert intersection(c1, Point(1, 0)) == [Point(1, 0)]
    assert intersection(c1, l1) == [Point(1, 0)]
    assert intersection(c1, l2) == [Point(0, -1)]
    assert intersection(c1, l3) in [pts_c1_l3, [pts_c1_l3[1], pts_c1_l3[0]]]
    assert intersection(c1, c2) == [Point(0, 1), Point(1, 0)]
    assert intersection(c1, c3) == [Point(sqrt(2)/2, sqrt(2)/2)]
    assert e1.intersection(l1) == [Point(1, 0)]
    assert e2.intersection(l4) == []
    assert e1.intersection(Circle(Point(0, 2), 1)) == [Point(0, 1)]
    assert e1.intersection(Circle(Point(5, 0), 1)) == []
    assert e1.intersection(Ellipse(Point(2, 0), 1, 1)) == [Point(1, 0)]
    assert e1.intersection(Ellipse(Point(5, 0), 1, 1,)) == []
    assert e1.intersection(Point(2, 0)) == []
    assert e1.intersection(e1) == e1

    # some special case intersections
    csmall = Circle(p1, 3)
    cbig = Circle(p1, 5)
    cout = Circle(Point(5, 5), 1)
    # one circle inside of another
    assert csmall.intersection(cbig) == []
    # separate circles
    assert csmall.intersection(cout) == []
    # coincident circles
    assert csmall.intersection(csmall) == csmall

    v = sqrt(2)
    t1 = Triangle(Point(0, v), Point(0, -v), Point(v, 0))
    points = intersection(t1, c1)
    assert len(points) == 4
    assert Point(0, 1) in points
    assert Point(0, -1) in points
    assert Point(v/2, v/2) in points
    assert Point(v/2, -v/2) in points

    circ = Circle(Point(0, 0), 5)
    elip = Ellipse(Point(0, 0), 5, 20)
    assert intersection(circ, elip) in \
        [[Point(5, 0), Point(-5, 0)], [Point(-5, 0), Point(5, 0)]]
    assert elip.tangent_lines(Point(0, 0)) == []
    elip = Ellipse(Point(0, 0), 3, 2)
    assert elip.tangent_lines(Point(3, 0)) == \
        [Line(Point(3, 0), Point(3, -12))]

    e1 = Ellipse(Point(0, 0), 5, 10)
    e2 = Ellipse(Point(2, 1), 4, 8)
    a = 53/17
    c = 2*sqrt(3991)/17
    ans = [Point(a - c/8, a/2 + c), Point(a + c/8, a/2 - c)]
    assert e1.intersection(e2) == ans
    e2 = Ellipse(Point(x, y), 4, 8)
    c = sqrt(3991)
    ans = [Point(-c/68 + a, 2*c/17 + a/2), Point(c/68 + a, -2*c/17 + a/2)]
    assert [p.subs({x: 2, y:1}) for p in e1.intersection(e2)] == ans

    # Combinations of above
    assert e3.is_tangent(e3.tangent_lines(p1 + Point(y1, 0))[0])

    e = Ellipse((1, 2), 3, 2)
    assert e.tangent_lines(Point(10, 0)) == \
        [Line(Point(10, 0), Point(1, 0)),
        Line(Point(10, 0), Point(14/5, 18/5))]

    # encloses_point
    e = Ellipse((0, 0), 1, 2)
    assert e.encloses_point(e.center)
    assert e.encloses_point(e.center + Point(0, e.vradius - Rational(1, 10)))
    assert e.encloses_point(e.center + Point(e.hradius - Rational(1, 10), 0))
    assert e.encloses_point(e.center + Point(e.hradius, 0)) is False
    assert e.encloses_point(
        e.center + Point(e.hradius + Rational(1, 10), 0)) is False
    e = Ellipse((0, 0), 2, 1)
    assert e.encloses_point(e.center)
    assert e.encloses_point(e.center + Point(0, e.vradius - Rational(1, 10)))
    assert e.encloses_point(e.center + Point(e.hradius - Rational(1, 10), 0))
    assert e.encloses_point(e.center + Point(e.hradius, 0)) is False
    assert e.encloses_point(
        e.center + Point(e.hradius + Rational(1, 10), 0)) is False
    assert c1.encloses_point(Point(1, 0)) is False
    assert c1.encloses_point(Point(0.3, 0.4)) is True

    assert e.scale(2, 3) == Ellipse((0, 0), 4, 3)
    assert e.scale(3, 6) == Ellipse((0, 0), 6, 6)
    assert e.rotate(pi) == e
    assert e.rotate(pi, (1, 2)) == Ellipse(Point(2, 4), 2, 1)
    raises(NotImplementedError, lambda: e.rotate(pi/3))

    # transformations
    c = Circle((1, 1), 2)
    assert c.scale(-1) == Circle((-1, 1), 2)
    assert c.scale(y=-1) == Circle((1, -1), 2)
    assert c.scale(2) == Ellipse((2, 1), 4, 2)
Example #19
0
def test_ellipse():
    p1 = Point(0, 0)
    p2 = Point(1, 1)
    p3 = Point(x1, x2)
    p4 = Point(0, 1)
    p5 = Point(-1, 0)

    e1 = Ellipse(p1, 1, 1)
    e2 = Ellipse(p2, half, 1)
    e3 = Ellipse(p1, y1, y1)
    c1 = Circle(p1, 1)
    c2 = Circle(p2,1)
    c3 = Circle(Point(sqrt(2),sqrt(2)),1)

    # Test creation with three points
    cen,rad = Point(3*half, 2), 5*half
    assert Circle(Point(0,0), Point(3,0), Point(0,4)) == Circle(cen, rad)
    raises(GeometryError, "Circle(Point(0,0), Point(1,1), Point(2,2))")

    # Basic Stuff
    assert e1 == c1
    assert e1 != e2
    assert p4 in e1
    assert p2 not in e2
    assert e1.area == pi
    assert e2.area == pi/2
    assert e3.area == pi*(y1**2)
    assert c1.area == e1.area
    assert c1.circumference == 2*pi

    assert e2.arbitrary_point() in e2
    for ind in xrange(0, 5):
        assert e3.random_point() in e3

    # Foci
    f1,f2 = Point(sqrt(12), 0), Point(-sqrt(12), 0)
    ef = Ellipse(Point(0, 0), 4, 2)
    assert ef.foci in [(f1, f2), (f2, f1)]

    # Tangents
    v = sqrt(2) / 2
    p1_1 = Point(v, v)
    p1_2 = p2 + Point(half, 0)
    p1_3 = p2 + Point(0, 1)
    assert e1.tangent_line(p4) == c1.tangent_line(p4)
    assert e2.tangent_line(p1_2) == Line(p1_2, p2 + Point(half, 1))
    assert e2.tangent_line(p1_3) == Line(p1_3, p2 + Point(half, 1))
    assert c1.tangent_line(p1_1) == Line(p1_1, Point(0, sqrt(2)))
    assert e2.is_tangent(Line(p1_2, p2 + Point(half, 1)))
    assert e2.is_tangent(Line(p1_3, p2 + Point(half, 1)))
    assert c1.is_tangent(Line(p1_1, Point(0, sqrt(2))))
    assert e1.is_tangent(Line(Point(0, 0), Point(1, 1))) == False

    # Intersection
    l1 = Line(Point(1, -5), Point(1, 5))
    l2 = Line(Point(-5, -1), Point(5, -1))
    l3 = Line(Point(-1, -1), Point(1, 1))
    l4 = Line(Point(-10, 0), Point(0, 10))
    pts_c1_l3 = [Point(sqrt(2)/2, sqrt(2)/2), Point(-sqrt(2)/2, -sqrt(2)/2)]

    assert intersection(e2, l4) == []
    assert intersection(c1, Point(1, 0)) == [Point(1, 0)]
    assert intersection(c1, l1) == [Point(1, 0)]
    assert intersection(c1, l2) == [Point(0, -1)]
    assert intersection(c1, l3) in [pts_c1_l3, [pts_c1_l3[1], pts_c1_l3[0]]]
    assert intersection(c1, c2) in [[(1,0), (0,1)],[(0,1),(1,0)]]
    assert intersection(c1, c3) == [(sqrt(2)/2, sqrt(2)/2)]

    v = sqrt(2)
    t1 = Triangle(Point(0, v), Point(0, -v), Point(v, 0))
    points = intersection(t1, c1)
    assert len(points) == 4
    assert Point(0, 1) in points
    assert Point(0, -1) in points
    assert Point(v/2, v/2) in points
    assert Point(v/2, -v/2) in points

    e1 = Circle(Point(0, 0), 5)
    e2 = Ellipse(Point(0, 0), 5, 20)
    assert intersection(e1, e2) in \
        [[Point(5, 0), Point(-5, 0)], [Point(-5, 0), Point(5, 0)]]

    # Combinations of above
    assert e3.is_tangent(e3.tangent_line(p1 + Point(y1, 0)))
Example #20
0
def test_construction():
    e1 = Ellipse(hradius=2, vradius=1, eccentricity=None)
    assert e1.eccentricity == sqrt(3) / 2

    e2 = Ellipse(hradius=2, vradius=None, eccentricity=sqrt(3) / 2)
    assert e2.vradius == 1

    e3 = Ellipse(hradius=None, vradius=1, eccentricity=sqrt(3) / 2)
    assert e3.hradius == 2

    # filter(None, iterator) filters out anything falsey, including 0
    # eccentricity would be filtered out in this case and the constructor would throw an error
    e4 = Ellipse(Point(0, 0), hradius=1, eccentricity=0)
    assert e4.vradius == 1

    #tests for eccentricity > 1
    raises(GeometryError,
           lambda: Ellipse(Point(3, 1), hradius=3, eccentricity=S(3) / 2))
    raises(GeometryError,
           lambda: Ellipse(Point(3, 1), hradius=3, eccentricity=sec(5)))
    raises(GeometryError,
           lambda: Ellipse(Point(3, 1), hradius=3, eccentricity=S.Pi - S(2)))

    #tests for eccentricity = 1
    #if vradius is not defined
    assert Ellipse(None, 1, None, 1).length == 2
    #if hradius is not defined
    raises(GeometryError, lambda: Ellipse(None, None, 1, eccentricity=1))

    #tests for eccentricity < 0
    raises(GeometryError,
           lambda: Ellipse(Point(3, 1), hradius=3, eccentricity=-3))
    raises(GeometryError,
           lambda: Ellipse(Point(3, 1), hradius=3, eccentricity=-0.5))
Example #21
0
def test_ellipse_geom():
    x = Symbol('x', real=True)
    y = Symbol('y', real=True)
    t = Symbol('t', real=True)
    y1 = Symbol('y1', real=True)
    half = S.Half
    p1 = Point(0, 0)
    p2 = Point(1, 1)
    p4 = Point(0, 1)

    e1 = Ellipse(p1, 1, 1)
    e2 = Ellipse(p2, half, 1)
    e3 = Ellipse(p1, y1, y1)
    c1 = Circle(p1, 1)
    c2 = Circle(p2, 1)
    c3 = Circle(Point(sqrt(2), sqrt(2)), 1)
    l1 = Line(p1, p2)

    # Test creation with three points
    cen, rad = Point(3 * half, 2), 5 * half
    assert Circle(Point(0, 0), Point(3, 0), Point(0, 4)) == Circle(cen, rad)
    assert Circle(Point(0, 0), Point(1, 1),
                  Point(2, 2)) == Segment2D(Point2D(0, 0), Point2D(2, 2))

    raises(ValueError, lambda: Ellipse(None, None, None, 1))
    raises(ValueError, lambda: Ellipse())
    raises(GeometryError, lambda: Circle(Point(0, 0)))
    raises(GeometryError, lambda: Circle(Symbol('x') * Symbol('y')))

    # Basic Stuff
    assert Ellipse(None, 1, 1).center == Point(0, 0)
    assert e1 == c1
    assert e1 != e2
    assert e1 != l1
    assert p4 in e1
    assert e1 in e1
    assert e2 in e2
    assert 1 not in e2
    assert p2 not in e2
    assert e1.area == pi
    assert e2.area == pi / 2
    assert e3.area == pi * y1 * abs(y1)
    assert c1.area == e1.area
    assert c1.circumference == e1.circumference
    assert e3.circumference == 2 * pi * y1
    assert e1.plot_interval() == e2.plot_interval() == [t, -pi, pi]
    assert e1.plot_interval(x) == e2.plot_interval(x) == [x, -pi, pi]

    assert c1.minor == 1
    assert c1.major == 1
    assert c1.hradius == 1
    assert c1.vradius == 1

    assert Ellipse((1, 1), 0, 0) == Point(1, 1)
    assert Ellipse((1, 1), 1, 0) == Segment(Point(0, 1), Point(2, 1))
    assert Ellipse((1, 1), 0, 1) == Segment(Point(1, 0), Point(1, 2))

    # Private Functions
    assert hash(c1) == hash(Circle(Point(1, 0), Point(0, 1), Point(0, -1)))
    assert c1 in e1
    assert (Line(p1, p2) in e1) is False
    assert e1.__cmp__(e1) == 0
    assert e1.__cmp__(Point(0, 0)) > 0

    # Encloses
    assert e1.encloses(Segment(Point(-0.5, -0.5), Point(0.5, 0.5))) is True
    assert e1.encloses(Line(p1, p2)) is False
    assert e1.encloses(Ray(p1, p2)) is False
    assert e1.encloses(e1) is False
    assert e1.encloses(
        Polygon(Point(-0.5, -0.5), Point(-0.5, 0.5), Point(0.5, 0.5))) is True
    assert e1.encloses(RegularPolygon(p1, 0.5, 3)) is True
    assert e1.encloses(RegularPolygon(p1, 5, 3)) is False
    assert e1.encloses(RegularPolygon(p2, 5, 3)) is False

    assert e2.arbitrary_point() in e2
    raises(ValueError,
           lambda: Ellipse(Point(x, y), 1, 1).arbitrary_point(parameter='x'))

    # Foci
    f1, f2 = Point(sqrt(12), 0), Point(-sqrt(12), 0)
    ef = Ellipse(Point(0, 0), 4, 2)
    assert ef.foci in [(f1, f2), (f2, f1)]

    # Tangents
    v = sqrt(2) / 2
    p1_1 = Point(v, v)
    p1_2 = p2 + Point(half, 0)
    p1_3 = p2 + Point(0, 1)
    assert e1.tangent_lines(p4) == c1.tangent_lines(p4)
    assert e2.tangent_lines(p1_2) == [
        Line(Point(Rational(3, 2), 1), Point(Rational(3, 2), S.Half))
    ]
    assert e2.tangent_lines(p1_3) == [
        Line(Point(1, 2), Point(Rational(5, 4), 2))
    ]
    assert c1.tangent_lines(p1_1) != [Line(p1_1, Point(0, sqrt(2)))]
    assert c1.tangent_lines(p1) == []
    assert e2.is_tangent(Line(p1_2, p2 + Point(half, 1)))
    assert e2.is_tangent(Line(p1_3, p2 + Point(half, 1)))
    assert c1.is_tangent(Line(p1_1, Point(0, sqrt(2))))
    assert e1.is_tangent(Line(Point(0, 0), Point(1, 1))) is False
    assert c1.is_tangent(e1) is True
    assert c1.is_tangent(Ellipse(Point(2, 0), 1, 1)) is True
    assert c1.is_tangent(Polygon(Point(1, 1), Point(1, -1), Point(2,
                                                                  0))) is True
    assert c1.is_tangent(Polygon(Point(1, 1), Point(1, 0), Point(2,
                                                                 0))) is False
    assert Circle(Point(5, 5), 3).is_tangent(Circle(Point(0, 5), 1)) is False

    assert Ellipse(Point(5, 5), 2, 1).tangent_lines(Point(0, 0)) == \
        [Line(Point(0, 0), Point(Rational(77, 25), Rational(132, 25))),
     Line(Point(0, 0), Point(Rational(33, 5), Rational(22, 5)))]
    assert Ellipse(Point(5, 5), 2, 1).tangent_lines(Point(3, 4)) == \
        [Line(Point(3, 4), Point(4, 4)), Line(Point(3, 4), Point(3, 5))]
    assert Circle(Point(5, 5), 2).tangent_lines(Point(3, 3)) == \
        [Line(Point(3, 3), Point(4, 3)), Line(Point(3, 3), Point(3, 4))]
    assert Circle(Point(5, 5), 2).tangent_lines(Point(5 - 2*sqrt(2), 5)) == \
        [Line(Point(5 - 2*sqrt(2), 5), Point(5 - sqrt(2), 5 - sqrt(2))),
     Line(Point(5 - 2*sqrt(2), 5), Point(5 - sqrt(2), 5 + sqrt(2))), ]
    assert Circle(Point(5, 5), 5).tangent_lines(Point(4, 0)) == \
        [Line(Point(4, 0), Point(Rational(40, 13), Rational(5, 13))),
     Line(Point(4, 0), Point(5, 0))]
    assert Circle(Point(5, 5), 5).tangent_lines(Point(0, 6)) == \
        [Line(Point(0, 6), Point(0, 7)),
        Line(Point(0, 6), Point(Rational(5, 13), Rational(90, 13)))]

    # for numerical calculations, we shouldn't demand exact equality,
    # so only test up to the desired precision
    def lines_close(l1, l2, prec):
        """ tests whether l1 and 12 are within 10**(-prec)
        of each other """
        return abs(l1.p1 - l2.p1) < 10**(-prec) and abs(l1.p2 -
                                                        l2.p2) < 10**(-prec)

    def line_list_close(ll1, ll2, prec):
        return all(lines_close(l1, l2, prec) for l1, l2 in zip(ll1, ll2))

    e = Ellipse(Point(0, 0), 2, 1)
    assert e.normal_lines(Point(0, 0)) == \
        [Line(Point(0, 0), Point(0, 1)), Line(Point(0, 0), Point(1, 0))]
    assert e.normal_lines(Point(1, 0)) == \
        [Line(Point(0, 0), Point(1, 0))]
    assert e.normal_lines((0, 1)) == \
        [Line(Point(0, 0), Point(0, 1))]
    assert line_list_close(e.normal_lines(Point(1, 1), 2), [
        Line(Point(Rational(-51, 26), Rational(-1, 5)),
             Point(Rational(-25, 26), Rational(17, 83))),
        Line(Point(Rational(28, 29), Rational(-7, 8)),
             Point(Rational(57, 29), Rational(-9, 2)))
    ], 2)
    # test the failure of Poly.intervals and checks a point on the boundary
    p = Point(sqrt(3), S.Half)
    assert p in e
    assert line_list_close(e.normal_lines(p, 2), [
        Line(Point(Rational(-341, 171), Rational(-1, 13)),
             Point(Rational(-170, 171), Rational(5, 64))),
        Line(Point(Rational(26, 15), Rational(-1, 2)),
             Point(Rational(41, 15), Rational(-43, 26)))
    ], 2)
    # be sure to use the slope that isn't undefined on boundary
    e = Ellipse((0, 0), 2, 2 * sqrt(3) / 3)
    assert line_list_close(e.normal_lines((1, 1), 2), [
        Line(Point(Rational(-64, 33), Rational(-20, 71)),
             Point(Rational(-31, 33), Rational(2, 13))),
        Line(Point(1, -1), Point(2, -4))
    ], 2)
    # general ellipse fails except under certain conditions
    e = Ellipse((0, 0), x, 1)
    assert e.normal_lines((x + 1, 0)) == [Line(Point(0, 0), Point(1, 0))]
    raises(NotImplementedError, lambda: e.normal_lines((x + 1, 1)))
    # Properties
    major = 3
    minor = 1
    e4 = Ellipse(p2, minor, major)
    assert e4.focus_distance == sqrt(major**2 - minor**2)
    ecc = e4.focus_distance / major
    assert e4.eccentricity == ecc
    assert e4.periapsis == major * (1 - ecc)
    assert e4.apoapsis == major * (1 + ecc)
    assert e4.semilatus_rectum == major * (1 - ecc**2)
    # independent of orientation
    e4 = Ellipse(p2, major, minor)
    assert e4.focus_distance == sqrt(major**2 - minor**2)
    ecc = e4.focus_distance / major
    assert e4.eccentricity == ecc
    assert e4.periapsis == major * (1 - ecc)
    assert e4.apoapsis == major * (1 + ecc)

    # Intersection
    l1 = Line(Point(1, -5), Point(1, 5))
    l2 = Line(Point(-5, -1), Point(5, -1))
    l3 = Line(Point(-1, -1), Point(1, 1))
    l4 = Line(Point(-10, 0), Point(0, 10))
    pts_c1_l3 = [
        Point(sqrt(2) / 2,
              sqrt(2) / 2),
        Point(-sqrt(2) / 2, -sqrt(2) / 2)
    ]

    assert intersection(e2, l4) == []
    assert intersection(c1, Point(1, 0)) == [Point(1, 0)]
    assert intersection(c1, l1) == [Point(1, 0)]
    assert intersection(c1, l2) == [Point(0, -1)]
    assert intersection(c1, l3) in [pts_c1_l3, [pts_c1_l3[1], pts_c1_l3[0]]]
    assert intersection(c1, c2) == [Point(0, 1), Point(1, 0)]
    assert intersection(c1, c3) == [Point(sqrt(2) / 2, sqrt(2) / 2)]
    assert e1.intersection(l1) == [Point(1, 0)]
    assert e2.intersection(l4) == []
    assert e1.intersection(Circle(Point(0, 2), 1)) == [Point(0, 1)]
    assert e1.intersection(Circle(Point(5, 0), 1)) == []
    assert e1.intersection(Ellipse(Point(2, 0), 1, 1)) == [Point(1, 0)]
    assert e1.intersection(Ellipse(Point(5, 0), 1, 1)) == []
    assert e1.intersection(Point(2, 0)) == []
    assert e1.intersection(e1) == e1
    assert intersection(Ellipse(Point(0, 0), 2, 1),
                        Ellipse(Point(3, 0), 1, 2)) == [Point(2, 0)]
    assert intersection(Circle(Point(0, 0), 2), Circle(Point(3, 0),
                                                       1)) == [Point(2, 0)]
    assert intersection(Circle(Point(0, 0), 2), Circle(Point(7, 0), 1)) == []
    assert intersection(Ellipse(Point(0, 0), 5, 17),
                        Ellipse(Point(4, 0), 1, 0.2)) == [Point(5, 0)]
    assert intersection(Ellipse(Point(0, 0), 5, 17),
                        Ellipse(Point(4, 0), 0.999, 0.2)) == []
    assert Circle(
        (0, 0), S.Half).intersection(Triangle(
            (-1, 0), (1, 0),
            (0, 1))) == [Point(Rational(-1, 2), 0),
                         Point(S.Half, 0)]
    raises(TypeError, lambda: intersection(e2, Line((0, 0, 0), (0, 0, 1))))
    raises(TypeError, lambda: intersection(e2, Rational(12)))
    raises(TypeError, lambda: Ellipse.intersection(e2, 1))
    # some special case intersections
    csmall = Circle(p1, 3)
    cbig = Circle(p1, 5)
    cout = Circle(Point(5, 5), 1)
    # one circle inside of another
    assert csmall.intersection(cbig) == []
    # separate circles
    assert csmall.intersection(cout) == []
    # coincident circles
    assert csmall.intersection(csmall) == csmall

    v = sqrt(2)
    t1 = Triangle(Point(0, v), Point(0, -v), Point(v, 0))
    points = intersection(t1, c1)
    assert len(points) == 4
    assert Point(0, 1) in points
    assert Point(0, -1) in points
    assert Point(v / 2, v / 2) in points
    assert Point(v / 2, -v / 2) in points

    circ = Circle(Point(0, 0), 5)
    elip = Ellipse(Point(0, 0), 5, 20)
    assert intersection(circ, elip) in \
        [[Point(5, 0), Point(-5, 0)], [Point(-5, 0), Point(5, 0)]]
    assert elip.tangent_lines(Point(0, 0)) == []
    elip = Ellipse(Point(0, 0), 3, 2)
    assert elip.tangent_lines(Point(3, 0)) == \
        [Line(Point(3, 0), Point(3, -12))]

    e1 = Ellipse(Point(0, 0), 5, 10)
    e2 = Ellipse(Point(2, 1), 4, 8)
    a = Rational(53, 17)
    c = 2 * sqrt(3991) / 17
    ans = [Point(a - c / 8, a / 2 + c), Point(a + c / 8, a / 2 - c)]
    assert e1.intersection(e2) == ans
    e2 = Ellipse(Point(x, y), 4, 8)
    c = sqrt(3991)
    ans = [
        Point(-c / 68 + a,
              c * Rational(2, 17) + a / 2),
        Point(c / 68 + a,
              c * Rational(-2, 17) + a / 2)
    ]
    assert [p.subs({x: 2, y: 1}) for p in e1.intersection(e2)] == ans

    # Combinations of above
    assert e3.is_tangent(e3.tangent_lines(p1 + Point(y1, 0))[0])

    e = Ellipse((1, 2), 3, 2)
    assert e.tangent_lines(Point(10, 0)) == \
        [Line(Point(10, 0), Point(1, 0)),
        Line(Point(10, 0), Point(Rational(14, 5), Rational(18, 5)))]

    # encloses_point
    e = Ellipse((0, 0), 1, 2)
    assert e.encloses_point(e.center)
    assert e.encloses_point(e.center + Point(0, e.vradius - Rational(1, 10)))
    assert e.encloses_point(e.center + Point(e.hradius - Rational(1, 10), 0))
    assert e.encloses_point(e.center + Point(e.hradius, 0)) is False
    assert e.encloses_point(e.center +
                            Point(e.hradius + Rational(1, 10), 0)) is False
    e = Ellipse((0, 0), 2, 1)
    assert e.encloses_point(e.center)
    assert e.encloses_point(e.center + Point(0, e.vradius - Rational(1, 10)))
    assert e.encloses_point(e.center + Point(e.hradius - Rational(1, 10), 0))
    assert e.encloses_point(e.center + Point(e.hradius, 0)) is False
    assert e.encloses_point(e.center +
                            Point(e.hradius + Rational(1, 10), 0)) is False
    assert c1.encloses_point(Point(1, 0)) is False
    assert c1.encloses_point(Point(0.3, 0.4)) is True

    assert e.scale(2, 3) == Ellipse((0, 0), 4, 3)
    assert e.scale(3, 6) == Ellipse((0, 0), 6, 6)
    assert e.rotate(pi) == e
    assert e.rotate(pi, (1, 2)) == Ellipse(Point(2, 4), 2, 1)
    raises(NotImplementedError, lambda: e.rotate(pi / 3))

    # Circle rotation tests (Issue #11743)
    # Link - https://github.com/sympy/sympy/issues/11743
    cir = Circle(Point(1, 0), 1)
    assert cir.rotate(pi / 2) == Circle(Point(0, 1), 1)
    assert cir.rotate(pi / 3) == Circle(Point(S.Half, sqrt(3) / 2), 1)
    assert cir.rotate(pi / 3, Point(1, 0)) == Circle(Point(1, 0), 1)
    assert cir.rotate(pi / 3, Point(0, 1)) == Circle(
        Point(S.Half + sqrt(3) / 2, S.Half + sqrt(3) / 2), 1)
Example #22
0
def test_svg():
    e1 = Ellipse(Point(1, 0), 3, 2)
    assert e1._svg(
        2, "#FFAAFF"
    ) == '<ellipse fill="#FFAAFF" stroke="#555555" stroke-width="4.0" opacity="0.6" cx="1.00000000000000" cy="0" rx="3.00000000000000" ry="2.00000000000000"/>'
Example #23
0
def test_is_tangent():
    e1 = Ellipse(Point(0, 0), 3, 5)
    c1 = Circle(Point(2, -2), 7)
    assert e1.is_tangent(Point(0, 0)) is False
    assert e1.is_tangent(Point(3, 0)) is False
    assert e1.is_tangent(e1) is True
    assert e1.is_tangent(Ellipse((0, 0), 1, 2)) is False
    assert e1.is_tangent(Ellipse((0, 0), 3, 2)) is True
    assert c1.is_tangent(Ellipse((2, -2), 7, 1)) is True
    assert c1.is_tangent(Circle((11, -2), 2)) is True
    assert c1.is_tangent(Circle((7, -2), 2)) is True
    assert c1.is_tangent(Ray((-5, -2), (-15, -20))) is False
    assert c1.is_tangent(Ray((-3, -2), (-15, -20))) is False
    assert c1.is_tangent(Ray((-3, -22), (15, 20))) is False
    assert c1.is_tangent(Ray((9, 20), (9, -20))) is True
    assert e1.is_tangent(Segment((2, 2), (-7, 7))) is False
    assert e1.is_tangent(Segment((0, 0), (1, 2))) is False
    assert c1.is_tangent(Segment((0, 0), (-5, -2))) is False
    assert e1.is_tangent(Segment((3, 0), (12, 12))) is False
    assert e1.is_tangent(Segment((12, 12), (3, 0))) is False
    assert e1.is_tangent(Segment((-3, 0), (3, 0))) is False
    assert e1.is_tangent(Segment((-3, 5), (3, 5))) is True
    assert e1.is_tangent(Line((0, 0), (1, 1))) is False
    assert e1.is_tangent(Line((-3, 0), (-2.99, -0.001))) is False
    assert e1.is_tangent(Line((-3, 0), (-3, 1))) is True
    assert e1.is_tangent(Polygon((0, 0), (5, 5), (5, -5))) is False
    assert e1.is_tangent(Polygon((-100, -50), (-40, -334), (-70, -52))) is False
    assert e1.is_tangent(Polygon((-3, 0), (3, 0), (0, 1))) is False
    assert e1.is_tangent(Polygon((-3, 0), (3, 0), (0, 5))) is False
    assert e1.is_tangent(Polygon((-3, 0), (0, -5), (3, 0), (0, 5))) is False
    assert e1.is_tangent(Polygon((-3, -5), (-3, 5), (3, 5), (3, -5))) is True
    assert c1.is_tangent(Polygon((-3, -5), (-3, 5), (3, 5), (3, -5))) is False
    assert e1.is_tangent(Polygon((0, 0), (3, 0), (7, 7), (0, 5))) is False
    assert e1.is_tangent(Polygon((3, 12), (3, -12), (6, 5))) is True
    assert e1.is_tangent(Polygon((3, 12), (3, -12), (0, -5), (0, 5))) is False
    assert e1.is_tangent(Polygon((3, 0), (5, 7), (6, -5))) is False
    raises(TypeError, lambda: e1.is_tangent(Point(0, 0, 0)))
    raises(TypeError, lambda: e1.is_tangent(Rational(5)))
Example #24
0
def test_ellipse():
    p1 = Point(0, 0)
    p2 = Point(1, 1)
    p4 = Point(0, 1)

    e1 = Ellipse(p1, 1, 1)
    e2 = Ellipse(p2, half, 1)
    e3 = Ellipse(p1, y1, y1)
    c1 = Circle(p1, 1)
    c2 = Circle(p2, 1)
    c3 = Circle(Point(sqrt(2), sqrt(2)), 1)

    # Test creation with three points
    cen, rad = Point(3 * half, 2), 5 * half
    assert Circle(Point(0, 0), Point(3, 0), Point(0, 4)) == Circle(cen, rad)
    raises(GeometryError,
           lambda: Circle(Point(0, 0), Point(1, 1), Point(2, 2)))

    raises(ValueError, lambda: Ellipse(None, None, None, 1))
    raises(GeometryError, lambda: Circle(Point(0, 0)))

    # Basic Stuff
    assert Ellipse(None, 1, 1).center == Point(0, 0)
    assert e1 == c1
    assert e1 != e2
    assert p4 in e1
    assert p2 not in e2
    assert e1.area == pi
    assert e2.area == pi / 2
    assert e3.area == pi * (y1**2)
    assert c1.area == e1.area
    assert c1.circumference == e1.circumference
    assert e3.circumference == 2 * pi * y1
    assert e1.plot_interval() == e2.plot_interval() == [t, -pi, pi]
    assert e1.plot_interval(x) == e2.plot_interval(x) == [x, -pi, pi]
    assert Ellipse(None, 1, None, 1).circumference == 2 * pi
    assert c1.minor == 1
    assert c1.major == 1
    assert c1.hradius == 1
    assert c1.vradius == 1

    # Private Functions
    assert hash(c1) == hash(Circle(Point(1, 0), Point(0, 1), Point(0, -1)))
    assert c1 in e1
    assert (Line(p1, p2) in e1) == False
    assert e1.__cmp__(e1) == 0
    assert e1.__cmp__(Point(0, 0)) > 0

    # Encloses
    assert e1.encloses(Segment(Point(-0.5, -0.5), Point(0.5, 0.5))) == True
    assert e1.encloses(Line(p1, p2)) == False
    assert e1.encloses(Ray(p1, p2)) == False
    assert e1.encloses(e1) == False
    assert e1.encloses(
        Polygon(Point(-0.5, -0.5), Point(-0.5, 0.5), Point(0.5, 0.5))) == True
    assert e1.encloses(RegularPolygon(p1, 0.5, 3)) == True
    assert e1.encloses(RegularPolygon(p1, 5, 3)) == False
    assert e1.encloses(RegularPolygon(p2, 5, 3)) == False

    # with generic symbols, the hradius is assumed to contain the major radius
    M = Symbol('M')
    m = Symbol('m')
    c = Ellipse(p1, M, m).circumference
    _x = c.atoms(Dummy).pop()
    assert c == \
        4*M*C.Integral(sqrt((1 - _x**2*(M**2 - m**2)/M**2)/(1 - _x**2)), (_x, 0, 1))

    assert e2.arbitrary_point() in e2

    # Foci
    f1, f2 = Point(sqrt(12), 0), Point(-sqrt(12), 0)
    ef = Ellipse(Point(0, 0), 4, 2)
    assert ef.foci in [(f1, f2), (f2, f1)]

    # Tangents
    v = sqrt(2) / 2
    p1_1 = Point(v, v)
    p1_2 = p2 + Point(half, 0)
    p1_3 = p2 + Point(0, 1)
    assert e1.tangent_lines(p4) == c1.tangent_lines(p4)
    assert e2.tangent_lines(p1_2) == [Line(p1_2, p2 + Point(half, 1))]
    assert e2.tangent_lines(p1_3) == [Line(p1_3, p2 + Point(half, 1))]
    assert c1.tangent_lines(p1_1) == [Line(p1_1, Point(0, sqrt(2)))]
    assert c1.tangent_lines(p1) == []
    assert e2.is_tangent(Line(p1_2, p2 + Point(half, 1)))
    assert e2.is_tangent(Line(p1_3, p2 + Point(half, 1)))
    assert c1.is_tangent(Line(p1_1, Point(0, sqrt(2))))
    assert e1.is_tangent(Line(Point(0, 0), Point(1, 1))) == False
    assert c1.is_tangent(e1) == False
    assert c1.is_tangent(Ellipse(Point(2, 0), 1, 1)) == True
    assert c1.is_tangent(Polygon(Point(1, 1), Point(1, -1), Point(2,
                                                                  0))) == True
    assert c1.is_tangent(Polygon(Point(1, 1), Point(1, 0), Point(2,
                                                                 0))) == False


    assert Ellipse(Point(5, 5), 2, 1).tangent_lines(Point(0, 0)) == \
    [Line(Point(0, 0), Point(S(77)/25, S(132)/25)),
     Line(Point(0, 0), Point(S(33)/5, S(22)/5))]
    assert Ellipse(Point(5, 5), 2, 1).tangent_lines(Point(3, 4)) == \
    [Line(Point(3, 4), Point(4, 4)), Line(Point(3, 4), Point(3, 5))]
    assert Circle(Point(5, 5), 2).tangent_lines(Point(3, 3)) == \
    [Line(Point(3, 3), Point(4, 3)), Line(Point(3, 3), Point(3, 4))]
    assert Circle(Point(5, 5), 2).tangent_lines(Point(5 - 2*sqrt(2), 5)) == \
    [Line(Point(5 - 2*sqrt(2), 5), Point(5 - sqrt(2), 5 - sqrt(2))),
     Line(Point(5 - 2*sqrt(2), 5), Point(5 - sqrt(2), 5 + sqrt(2))),]

    # Properties
    major = 3
    minor = 1
    e4 = Ellipse(p2, minor, major)
    assert e4.focus_distance == sqrt(major**2 - minor**2)
    ecc = e4.focus_distance / major
    assert e4.eccentricity == ecc
    assert e4.periapsis == major * (1 - ecc)
    assert e4.apoapsis == major * (1 + ecc)
    # independent of orientation
    e4 = Ellipse(p2, major, minor)
    assert e4.focus_distance == sqrt(major**2 - minor**2)
    ecc = e4.focus_distance / major
    assert e4.eccentricity == ecc
    assert e4.periapsis == major * (1 - ecc)
    assert e4.apoapsis == major * (1 + ecc)

    # Intersection
    l1 = Line(Point(1, -5), Point(1, 5))
    l2 = Line(Point(-5, -1), Point(5, -1))
    l3 = Line(Point(-1, -1), Point(1, 1))
    l4 = Line(Point(-10, 0), Point(0, 10))
    pts_c1_l3 = [
        Point(sqrt(2) / 2,
              sqrt(2) / 2),
        Point(-sqrt(2) / 2, -sqrt(2) / 2)
    ]

    assert intersection(e2, l4) == []
    assert intersection(c1, Point(1, 0)) == [Point(1, 0)]
    assert intersection(c1, l1) == [Point(1, 0)]
    assert intersection(c1, l2) == [Point(0, -1)]
    assert intersection(c1, l3) in [pts_c1_l3, [pts_c1_l3[1], pts_c1_l3[0]]]
    assert intersection(c1, c2) == [Point(0, 1), Point(1, 0)]
    assert intersection(c1, c3) == [Point(sqrt(2) / 2, sqrt(2) / 2)]
    assert e1.intersection(l1) == [Point(1, 0)]
    assert e2.intersection(l4) == []
    assert e1.intersection(Circle(Point(0, 2), 1)) == [Point(0, 1)]
    assert e1.intersection(Circle(Point(5, 0), 1)) == []
    assert e1.intersection(Ellipse(Point(2, 0), 1, 1)) == [Point(1, 0)]
    assert e1.intersection(Ellipse(
        Point(5, 0),
        1,
        1,
    )) == []
    assert e1.intersection(Point(2, 0)) == []
    assert e1.intersection(e1) == e1

    # some special case intersections
    csmall = Circle(p1, 3)
    cbig = Circle(p1, 5)
    cout = Circle(Point(5, 5), 1)
    # one circle inside of another
    assert csmall.intersection(cbig) == []
    # separate circles
    assert csmall.intersection(cout) == []
    # coincident circles
    assert csmall.intersection(csmall) == csmall

    v = sqrt(2)
    t1 = Triangle(Point(0, v), Point(0, -v), Point(v, 0))
    points = intersection(t1, c1)
    assert len(points) == 4
    assert Point(0, 1) in points
    assert Point(0, -1) in points
    assert Point(v / 2, v / 2) in points
    assert Point(v / 2, -v / 2) in points

    circ = Circle(Point(0, 0), 5)
    elip = Ellipse(Point(0, 0), 5, 20)
    assert intersection(circ, elip) in \
        [[Point(5, 0), Point(-5, 0)], [Point(-5, 0), Point(5, 0)]]
    assert elip.tangent_lines(Point(0, 0)) == []
    elip = Ellipse(Point(0, 0), 3, 2)
    assert elip.tangent_lines(Point(3,
                                    0)) == [Line(Point(3, 0), Point(3, -12))]

    e1 = Ellipse(Point(0, 0), 5, 10)
    e2 = Ellipse(Point(2, 1), 4, 8)
    a = S(53) / 17
    c = 2 * sqrt(3991) / 17
    ans = [Point(a - c / 8, a / 2 + c), Point(a + c / 8, a / 2 - c)]
    assert e1.intersection(e2) == ans
    e2 = Ellipse(Point(x, y), 4, 8)
    assert [p.subs({x: 2, y: 1}) for p in e1.intersection(e2)] == ans

    # Combinations of above
    assert e3.is_tangent(e3.tangent_lines(p1 + Point(y1, 0))[0])

    e = Ellipse((1, 2), 3, 2)
    assert e.tangent_lines(Point(10, 0)) == \
       [Line(Point(10, 0), Point(1, 0)),
        Line(Point(10, 0), Point(S(14)/5, S(18)/5))]

    # encloses_point
    e = Ellipse((0, 0), 1, 2)
    assert e.encloses_point(e.center)
    assert e.encloses_point(e.center + Point(0, e.vradius - Rational(1, 10)))
    assert e.encloses_point(e.center + Point(e.hradius - Rational(1, 10), 0))
    assert e.encloses_point(e.center + Point(e.hradius, 0)) is False
    assert e.encloses_point(e.center +
                            Point(e.hradius + Rational(1, 10), 0)) is False
    e = Ellipse((0, 0), 2, 1)
    assert e.encloses_point(e.center)
    assert e.encloses_point(e.center + Point(0, e.vradius - Rational(1, 10)))
    assert e.encloses_point(e.center + Point(e.hradius - Rational(1, 10), 0))
    assert e.encloses_point(e.center + Point(e.hradius, 0)) is False
    assert e.encloses_point(e.center +
                            Point(e.hradius + Rational(1, 10), 0)) is False
    assert c1.encloses_point(Point(1, 0)) is False
    assert c1.encloses_point(Point(0.3, 0.4)) is True

    assert e.scale(2, 3) == Ellipse((0, 0), 4, 3)
    assert e.scale(3, 6) == Ellipse((0, 0), 6, 6)
    assert e.rotate(pi / 3) == e
    assert e.rotate(pi/3, (1, 2)) == \
        Ellipse(Point(S(1)/2 + sqrt(3), -sqrt(3)/2 + 1), 2, 1)
Example #25
0
def test_parameter_value():
    t = Symbol('t')
    e = Ellipse(Point(0, 0), 3, 5)
    assert e.parameter_value((3, 0), t) == {t: 0}
    raises(ValueError, lambda: e.parameter_value((4, 0), t))
Example #26
0
def test_ellipse():
    p1 = Point(0, 0)
    p2 = Point(1, 1)
    p3 = Point(x1, x2)
    p4 = Point(0, 1)
    p5 = Point(-1, 0)

    e1 = Ellipse(p1, 1, 1)
    e2 = Ellipse(p2, half, 1)
    e3 = Ellipse(p1, y1, y1)
    c1 = Circle(p1, 1)
    c2 = Circle(p2,1)
    c3 = Circle(Point(sqrt(2),sqrt(2)),1)

    # Test creation with three points
    cen,rad = Point(3*half, 2), 5*half
    assert Circle(Point(0,0), Point(3,0), Point(0,4)) == Circle(cen, rad)
    raises(GeometryError, "Circle(Point(0,0), Point(1,1), Point(2,2))")

    # Basic Stuff
    assert e1 == c1
    assert e1 != e2
    assert p4 in e1
    assert p2 not in e2
    assert e1.area == pi
    assert e2.area == pi/2
    assert e3.area == pi*(y1**2)
    assert c1.area == e1.area
    assert c1.circumference == e1.circumference
    assert e3.circumference == 2*pi*y1

    a = Symbol('a')
    b = Symbol('b')
    e5 = Ellipse(p1, a, b)
    assert e5.circumference == 4*a*C.Integral(((1 - x**2*Abs(b**2 - a**2)/a**2)/(1 - x**2))**(S(1)/2),\
                                            (x, 0, 1))

    assert e2.arbitrary_point() in e2

    # Foci
    f1,f2 = Point(sqrt(12), 0), Point(-sqrt(12), 0)
    ef = Ellipse(Point(0, 0), 4, 2)
    assert ef.foci in [(f1, f2), (f2, f1)]

    # Tangents
    v = sqrt(2) / 2
    p1_1 = Point(v, v)
    p1_2 = p2 + Point(half, 0)
    p1_3 = p2 + Point(0, 1)
    assert e1.tangent_line(p4) == c1.tangent_line(p4)
    assert e2.tangent_line(p1_2) == Line(p1_2, p2 + Point(half, 1))
    assert e2.tangent_line(p1_3) == Line(p1_3, p2 + Point(half, 1))
    assert c1.tangent_line(p1_1) == Line(p1_1, Point(0, sqrt(2)))
    assert e2.is_tangent(Line(p1_2, p2 + Point(half, 1)))
    assert e2.is_tangent(Line(p1_3, p2 + Point(half, 1)))
    assert c1.is_tangent(Line(p1_1, Point(0, sqrt(2))))
    assert e1.is_tangent(Line(Point(0, 0), Point(1, 1))) == False

    # Intersection
    l1 = Line(Point(1, -5), Point(1, 5))
    l2 = Line(Point(-5, -1), Point(5, -1))
    l3 = Line(Point(-1, -1), Point(1, 1))
    l4 = Line(Point(-10, 0), Point(0, 10))
    pts_c1_l3 = [Point(sqrt(2)/2, sqrt(2)/2), Point(-sqrt(2)/2, -sqrt(2)/2)]

    assert intersection(e2, l4) == []
    assert intersection(c1, Point(1, 0)) == [Point(1, 0)]
    assert intersection(c1, l1) == [Point(1, 0)]
    assert intersection(c1, l2) == [Point(0, -1)]
    assert intersection(c1, l3) in [pts_c1_l3, [pts_c1_l3[1], pts_c1_l3[0]]]
    assert intersection(c1, c2) in [[(1,0), (0,1)],[(0,1),(1,0)]]
    assert intersection(c1, c3) == [(sqrt(2)/2, sqrt(2)/2)]

    # some special case intersections
    csmall = Circle(p1, 3)
    cbig = Circle(p1, 5)
    cout = Circle(Point(5, 5), 1)
    # one circle inside of another
    assert csmall.intersection(cbig) == []
    # separate circles
    assert csmall.intersection(cout) == []
    # coincident circles
    assert csmall.intersection(csmall) == csmall

    v = sqrt(2)
    t1 = Triangle(Point(0, v), Point(0, -v), Point(v, 0))
    points = intersection(t1, c1)
    assert len(points) == 4
    assert Point(0, 1) in points
    assert Point(0, -1) in points
    assert Point(v/2, v/2) in points
    assert Point(v/2, -v/2) in points

    e1 = Circle(Point(0, 0), 5)
    e2 = Ellipse(Point(0, 0), 5, 20)
    assert intersection(e1, e2) in \
        [[Point(5, 0), Point(-5, 0)], [Point(-5, 0), Point(5, 0)]]

    # FAILING ELLIPSE INTERSECTION GOES HERE

    # Combinations of above
    assert e3.is_tangent(e3.tangent_line(p1 + Point(y1, 0)))

    major = 3
    minor = 1
    e4 = Ellipse(p2, major, minor)
    assert e4.focus_distance == sqrt(abs(major**2 - minor**2))
    ecc = e4.focus_distance / major
    assert e4.eccentricity == ecc
    assert e4.periapsis == major*(1 - ecc)
    assert e4.apoapsis == major*(1 + ecc)
Example #27
0
def test_ellipse():
    p1 = Point(0, 0)
    p2 = Point(1, 1)
    p4 = Point(0, 1)

    e1 = Ellipse(p1, 1, 1)
    e2 = Ellipse(p2, half, 1)
    e3 = Ellipse(p1, y1, y1)
    c1 = Circle(p1, 1)
    c2 = Circle(p2, 1)
    c3 = Circle(Point(sqrt(2), sqrt(2)), 1)

    # Test creation with three points
    cen, rad = Point(3 * half, 2), 5 * half
    assert Circle(Point(0, 0), Point(3, 0), Point(0, 4)) == Circle(cen, rad)
    raises(GeometryError, lambda: Circle(Point(0, 0), Point(1, 1), Point(2, 2)))

    raises(ValueError, lambda: Ellipse(None, None, None, 1))
    raises(GeometryError, lambda: Circle(Point(0, 0)))

    # Basic Stuff
    assert Ellipse(None, 1, 1).center == Point(0, 0)
    assert e1 == c1
    assert e1 != e2
    assert p4 in e1
    assert p2 not in e2
    assert e1.area == pi
    assert e2.area == pi / 2
    assert e3.area == pi * (y1 ** 2)
    assert c1.area == e1.area
    assert c1.circumference == e1.circumference
    assert e3.circumference == 2 * pi * y1
    assert e1.plot_interval() == e2.plot_interval() == [t, -pi, pi]
    assert e1.plot_interval(x) == e2.plot_interval(x) == [x, -pi, pi]
    assert Ellipse(None, 1, None, 1).circumference == 2 * pi
    assert c1.minor == 1
    assert c1.major == 1
    assert c1.hradius == 1
    assert c1.vradius == 1

    # Private Functions
    assert hash(c1) == hash(Circle(Point(1, 0), Point(0, 1), Point(0, -1)))
    assert c1 in e1
    assert (Line(p1, p2) in e1) == False
    assert e1.__cmp__(e1) == 0
    assert e1.__cmp__(Point(0, 0)) > 0

    # Encloses
    assert e1.encloses(Segment(Point(-0.5, -0.5), Point(0.5, 0.5))) == True
    assert e1.encloses(Line(p1, p2)) == False
    assert e1.encloses(Ray(p1, p2)) == False
    assert e1.encloses(e1) == False
    assert e1.encloses(Polygon(Point(-0.5, -0.5), Point(-0.5, 0.5), Point(0.5, 0.5))) == True
    assert e1.encloses(RegularPolygon(p1, 0.5, 3)) == True
    assert e1.encloses(RegularPolygon(p1, 5, 3)) == False
    assert e1.encloses(RegularPolygon(p2, 5, 3)) == False

    # with generic symbols, the hradius is assumed to contain the major radius
    M = Symbol("M")
    m = Symbol("m")
    c = Ellipse(p1, M, m).circumference
    _x = c.atoms(Dummy).pop()
    assert c == 4 * M * C.Integral(sqrt((1 - _x ** 2 * (M ** 2 - m ** 2) / M ** 2) / (1 - _x ** 2)), (_x, 0, 1))

    assert e2.arbitrary_point() in e2

    # Foci
    f1, f2 = Point(sqrt(12), 0), Point(-sqrt(12), 0)
    ef = Ellipse(Point(0, 0), 4, 2)
    assert ef.foci in [(f1, f2), (f2, f1)]

    # Tangents
    v = sqrt(2) / 2
    p1_1 = Point(v, v)
    p1_2 = p2 + Point(half, 0)
    p1_3 = p2 + Point(0, 1)
    assert e1.tangent_lines(p4) == c1.tangent_lines(p4)
    assert e2.tangent_lines(p1_2) == [Line(p1_2, p2 + Point(half, 1))]
    assert e2.tangent_lines(p1_3) == [Line(p1_3, p2 + Point(half, 1))]
    assert c1.tangent_lines(p1_1) == [Line(p1_1, Point(0, sqrt(2)))]
    assert c1.tangent_lines(p1) == []
    assert e2.is_tangent(Line(p1_2, p2 + Point(half, 1)))
    assert e2.is_tangent(Line(p1_3, p2 + Point(half, 1)))
    assert c1.is_tangent(Line(p1_1, Point(0, sqrt(2))))
    assert e1.is_tangent(Line(Point(0, 0), Point(1, 1))) == False
    assert c1.is_tangent(e1) == False
    assert c1.is_tangent(Ellipse(Point(2, 0), 1, 1)) == True
    assert c1.is_tangent(Polygon(Point(1, 1), Point(1, -1), Point(2, 0))) == True
    assert c1.is_tangent(Polygon(Point(1, 1), Point(1, 0), Point(2, 0))) == False

    assert Ellipse(Point(5, 5), 2, 1).tangent_lines(Point(0, 0)) == [
        Line(Point(0, 0), Point(S(77) / 25, S(132) / 25)),
        Line(Point(0, 0), Point(S(33) / 5, S(22) / 5)),
    ]
    assert Ellipse(Point(5, 5), 2, 1).tangent_lines(Point(3, 4)) == [
        Line(Point(3, 4), Point(4, 4)),
        Line(Point(3, 4), Point(3, 5)),
    ]
    assert Circle(Point(5, 5), 2).tangent_lines(Point(3, 3)) == [
        Line(Point(3, 3), Point(4, 3)),
        Line(Point(3, 3), Point(3, 4)),
    ]
    assert Circle(Point(5, 5), 2).tangent_lines(Point(5 - 2 * sqrt(2), 5)) == [
        Line(Point(5 - 2 * sqrt(2), 5), Point(5 - sqrt(2), 5 - sqrt(2))),
        Line(Point(5 - 2 * sqrt(2), 5), Point(5 - sqrt(2), 5 + sqrt(2))),
    ]

    # Properties
    major = 3
    minor = 1
    e4 = Ellipse(p2, minor, major)
    assert e4.focus_distance == sqrt(major ** 2 - minor ** 2)
    ecc = e4.focus_distance / major
    assert e4.eccentricity == ecc
    assert e4.periapsis == major * (1 - ecc)
    assert e4.apoapsis == major * (1 + ecc)
    # independent of orientation
    e4 = Ellipse(p2, major, minor)
    assert e4.focus_distance == sqrt(major ** 2 - minor ** 2)
    ecc = e4.focus_distance / major
    assert e4.eccentricity == ecc
    assert e4.periapsis == major * (1 - ecc)
    assert e4.apoapsis == major * (1 + ecc)

    # Intersection
    l1 = Line(Point(1, -5), Point(1, 5))
    l2 = Line(Point(-5, -1), Point(5, -1))
    l3 = Line(Point(-1, -1), Point(1, 1))
    l4 = Line(Point(-10, 0), Point(0, 10))
    pts_c1_l3 = [Point(sqrt(2) / 2, sqrt(2) / 2), Point(-sqrt(2) / 2, -sqrt(2) / 2)]

    assert intersection(e2, l4) == []
    assert intersection(c1, Point(1, 0)) == [Point(1, 0)]
    assert intersection(c1, l1) == [Point(1, 0)]
    assert intersection(c1, l2) == [Point(0, -1)]
    assert intersection(c1, l3) in [pts_c1_l3, [pts_c1_l3[1], pts_c1_l3[0]]]
    assert intersection(c1, c2) == [Point(0, 1), Point(1, 0)]
    assert intersection(c1, c3) == [Point(sqrt(2) / 2, sqrt(2) / 2)]
    assert e1.intersection(l1) == [Point(1, 0)]
    assert e2.intersection(l4) == []
    assert e1.intersection(Circle(Point(0, 2), 1)) == [Point(0, 1)]
    assert e1.intersection(Circle(Point(5, 0), 1)) == []
    assert e1.intersection(Ellipse(Point(2, 0), 1, 1)) == [Point(1, 0)]
    assert e1.intersection(Ellipse(Point(5, 0), 1, 1)) == []
    assert e1.intersection(Point(2, 0)) == []
    assert e1.intersection(e1) == e1

    # some special case intersections
    csmall = Circle(p1, 3)
    cbig = Circle(p1, 5)
    cout = Circle(Point(5, 5), 1)
    # one circle inside of another
    assert csmall.intersection(cbig) == []
    # separate circles
    assert csmall.intersection(cout) == []
    # coincident circles
    assert csmall.intersection(csmall) == csmall

    v = sqrt(2)
    t1 = Triangle(Point(0, v), Point(0, -v), Point(v, 0))
    points = intersection(t1, c1)
    assert len(points) == 4
    assert Point(0, 1) in points
    assert Point(0, -1) in points
    assert Point(v / 2, v / 2) in points
    assert Point(v / 2, -v / 2) in points

    circ = Circle(Point(0, 0), 5)
    elip = Ellipse(Point(0, 0), 5, 20)
    assert intersection(circ, elip) in [[Point(5, 0), Point(-5, 0)], [Point(-5, 0), Point(5, 0)]]
    assert elip.tangent_lines(Point(0, 0)) == []
    elip = Ellipse(Point(0, 0), 3, 2)
    assert elip.tangent_lines(Point(3, 0)) == [Line(Point(3, 0), Point(3, -12))]

    e1 = Ellipse(Point(0, 0), 5, 10)
    e2 = Ellipse(Point(2, 1), 4, 8)
    a = S(53) / 17
    c = 2 * sqrt(3991) / 17
    ans = [Point(a - c / 8, a / 2 + c), Point(a + c / 8, a / 2 - c)]
    assert e1.intersection(e2) == ans
    e2 = Ellipse(Point(x, y), 4, 8)
    assert [p.subs({x: 2, y: 1}) for p in e1.intersection(e2)] == ans

    # Combinations of above
    assert e3.is_tangent(e3.tangent_lines(p1 + Point(y1, 0))[0])

    e = Ellipse((1, 2), 3, 2)
    assert e.tangent_lines(Point(10, 0)) == [
        Line(Point(10, 0), Point(1, 0)),
        Line(Point(10, 0), Point(S(14) / 5, S(18) / 5)),
    ]

    # encloses_point
    e = Ellipse((0, 0), 1, 2)
    assert e.encloses_point(e.center)
    assert e.encloses_point(e.center + Point(0, e.vradius - Rational(1, 10)))
    assert e.encloses_point(e.center + Point(e.hradius - Rational(1, 10), 0))
    assert e.encloses_point(e.center + Point(e.hradius, 0)) is False
    assert e.encloses_point(e.center + Point(e.hradius + Rational(1, 10), 0)) is False
    e = Ellipse((0, 0), 2, 1)
    assert e.encloses_point(e.center)
    assert e.encloses_point(e.center + Point(0, e.vradius - Rational(1, 10)))
    assert e.encloses_point(e.center + Point(e.hradius - Rational(1, 10), 0))
    assert e.encloses_point(e.center + Point(e.hradius, 0)) is False
    assert e.encloses_point(e.center + Point(e.hradius + Rational(1, 10), 0)) is False
    assert c1.encloses_point(Point(1, 0)) is False
    assert c1.encloses_point(Point(0.3, 0.4)) is True

    assert e.scale(2, 3) == Ellipse((0, 0), 4, 3)
    assert e.scale(3, 6) == Ellipse((0, 0), 6, 6)
    assert e.rotate(pi / 3) == e
    assert e.rotate(pi / 3, (1, 2)) == Ellipse(Point(S(1) / 2 + sqrt(3), -sqrt(3) / 2 + 1), 2, 1)
Example #28
0
def test_is_tangent():
    e1 = Ellipse(Point(0, 0), 3, 5)
    c1 = Circle(Point(2, -2), 7)
    assert e1.is_tangent(Point(0, 0)) is False
    assert e1.is_tangent(Point(3, 0)) is False
    assert e1.is_tangent(e1) is True
    assert e1.is_tangent(Ellipse((0, 0), 1, 2)) is False
    assert e1.is_tangent(Ellipse((0, 0), 3, 2)) is True
    assert c1.is_tangent(Ellipse((2, -2), 7, 1)) is True
    assert c1.is_tangent(Circle((11, -2), 2)) is True
    assert c1.is_tangent(Circle((7, -2), 2)) is True
    assert c1.is_tangent(Ray((-5, -2), (-15, -20))) is False
    assert c1.is_tangent(Ray((-3, -2), (-15, -20))) is False
    assert c1.is_tangent(Ray((-3, -22), (15, 20))) is False
    assert c1.is_tangent(Ray((9, 20), (9, -20))) is True
    assert e1.is_tangent(Segment((2, 2), (-7, 7))) is False
    assert e1.is_tangent(Segment((0, 0), (1, 2))) is False
    assert c1.is_tangent(Segment((0, 0), (-5, -2))) is False
    assert e1.is_tangent(Segment((3, 0), (12, 12))) is False
    assert e1.is_tangent(Segment((12, 12), (3, 0))) is False
    assert e1.is_tangent(Segment((-3, 0), (3, 0))) is False
    assert e1.is_tangent(Segment((-3, 5), (3, 5))) is True
    assert e1.is_tangent(Line((10, 0), (10, 10))) is False
    assert e1.is_tangent(Line((0, 0), (1, 1))) is False
    assert e1.is_tangent(Line((-3, 0), (-2.99, -0.001))) is False
    assert e1.is_tangent(Line((-3, 0), (-3, 1))) is True
    assert e1.is_tangent(Polygon((0, 0), (5, 5), (5, -5))) is False
    assert e1.is_tangent(Polygon((-100, -50), (-40, -334),
                                 (-70, -52))) is False
    assert e1.is_tangent(Polygon((-3, 0), (3, 0), (0, 1))) is False
    assert e1.is_tangent(Polygon((-3, 0), (3, 0), (0, 5))) is False
    assert e1.is_tangent(Polygon((-3, 0), (0, -5), (3, 0), (0, 5))) is False
    assert e1.is_tangent(Polygon((-3, -5), (-3, 5), (3, 5), (3, -5))) is True
    assert c1.is_tangent(Polygon((-3, -5), (-3, 5), (3, 5), (3, -5))) is False
    assert e1.is_tangent(Polygon((0, 0), (3, 0), (7, 7), (0, 5))) is False
    assert e1.is_tangent(Polygon((3, 12), (3, -12), (6, 5))) is True
    assert e1.is_tangent(Polygon((3, 12), (3, -12), (0, -5), (0, 5))) is False
    assert e1.is_tangent(Polygon((3, 0), (5, 7), (6, -5))) is False
    raises(TypeError, lambda: e1.is_tangent(Point(0, 0, 0)))
    raises(TypeError, lambda: e1.is_tangent(Rational(5)))
Example #29
0
def test_ellipse():
    p1 = Point(0, 0)
    p2 = Point(1, 1)
    p3 = Point(x1, x2)
    p4 = Point(0, 1)
    p5 = Point(-1, 0)

    e1 = Ellipse(p1, 1, 1)
    e2 = Ellipse(p2, half, 1)
    e3 = Ellipse(p1, y1, y1)
    c1 = Circle(p1, 1)
    c2 = Circle(p2,1)
    c3 = Circle(Point(sqrt(2),sqrt(2)),1)

    # Test creation with three points
    cen,rad = Point(3*half, 2), 5*half
    assert Circle(Point(0,0), Point(3,0), Point(0,4)) == Circle(cen, rad)
    raises(GeometryError, "Circle(Point(0,0), Point(1,1), Point(2,2))")

    # Basic Stuff
    assert e1 == c1
    assert e1 != e2
    assert p4 in e1
    assert p2 not in e2
    assert e1.area == pi
    assert e2.area == pi/2
    assert e3.area == pi*(y1**2)
    assert c1.area == e1.area
    assert c1.circumference == e1.circumference
    assert e3.circumference == 2*pi*y1

    a = Symbol('a')
    b = Symbol('b')
    e5 = Ellipse(p1, a, b)
    assert e5.circumference == 4*a*C.Integral(((1 - x**2*Abs(b**2 - a**2)/a**2)/(1 - x**2))**(S(1)/2),\
                                            (x, 0, 1))

    assert e2.arbitrary_point() in e2
    for ind in xrange(0, 5):
        assert e3.random_point() in e3

    # Foci
    f1,f2 = Point(sqrt(12), 0), Point(-sqrt(12), 0)
    ef = Ellipse(Point(0, 0), 4, 2)
    assert ef.foci in [(f1, f2), (f2, f1)]

    # Tangents
    v = sqrt(2) / 2
    p1_1 = Point(v, v)
    p1_2 = p2 + Point(half, 0)
    p1_3 = p2 + Point(0, 1)
    assert e1.tangent_line(p4) == c1.tangent_line(p4)
    assert e2.tangent_line(p1_2) == Line(p1_2, p2 + Point(half, 1))
    assert e2.tangent_line(p1_3) == Line(p1_3, p2 + Point(half, 1))
    assert c1.tangent_line(p1_1) == Line(p1_1, Point(0, sqrt(2)))
    assert e2.is_tangent(Line(p1_2, p2 + Point(half, 1)))
    assert e2.is_tangent(Line(p1_3, p2 + Point(half, 1)))
    assert c1.is_tangent(Line(p1_1, Point(0, sqrt(2))))
    assert e1.is_tangent(Line(Point(0, 0), Point(1, 1))) == False

    # Intersection
    l1 = Line(Point(1, -5), Point(1, 5))
    l2 = Line(Point(-5, -1), Point(5, -1))
    l3 = Line(Point(-1, -1), Point(1, 1))
    l4 = Line(Point(-10, 0), Point(0, 10))
    pts_c1_l3 = [Point(sqrt(2)/2, sqrt(2)/2), Point(-sqrt(2)/2, -sqrt(2)/2)]

    assert intersection(e2, l4) == []
    assert intersection(c1, Point(1, 0)) == [Point(1, 0)]
    assert intersection(c1, l1) == [Point(1, 0)]
    assert intersection(c1, l2) == [Point(0, -1)]
    assert intersection(c1, l3) in [pts_c1_l3, [pts_c1_l3[1], pts_c1_l3[0]]]
    assert intersection(c1, c2) in [[(1,0), (0,1)],[(0,1),(1,0)]]
    assert intersection(c1, c3) == [(sqrt(2)/2, sqrt(2)/2)]

    # some special case intersections
    csmall = Circle(p1, 3)
    cbig = Circle(p1, 5)
    cout = Circle(Point(5, 5), 1)
    # one circle inside of another
    assert csmall.intersection(cbig) == []
    # separate circles
    assert csmall.intersection(cout) == []
    # coincident circles
    assert csmall.intersection(csmall) == csmall

    v = sqrt(2)
    t1 = Triangle(Point(0, v), Point(0, -v), Point(v, 0))
    points = intersection(t1, c1)
    assert len(points) == 4
    assert Point(0, 1) in points
    assert Point(0, -1) in points
    assert Point(v/2, v/2) in points
    assert Point(v/2, -v/2) in points

    e1 = Circle(Point(0, 0), 5)
    e2 = Ellipse(Point(0, 0), 5, 20)
    assert intersection(e1, e2) in \
        [[Point(5, 0), Point(-5, 0)], [Point(-5, 0), Point(5, 0)]]

    # FAILING ELLIPSE INTERSECTION GOES HERE

    # Combinations of above
    assert e3.is_tangent(e3.tangent_line(p1 + Point(y1, 0)))

    major = 3
    minor = 1
    e4 = Ellipse(p2, major, minor)
    assert e4.focus_distance == sqrt(abs(major**2 - minor**2))
    ecc = e4.focus_distance / major
    assert e4.eccentricity == ecc
    assert e4.periapsis == major*(1 - ecc)
    assert e4.apoapsis == major*(1 + ecc)
Example #30
0
def test_ellipse_intersection_fail():
    # these need the upgrade to the solver; when this works, move
    # these lines to the FAILING ELLIPSE INTERSECTION GOES HERE line in test_ellipse above.
    e1 = Ellipse(Point(0, 0), 5, 10)
    e2 = Ellipse(Point(2, 1), 4, 8)
    assert e1.intersection(e2) # when this no longer fails, supply the answer
Example #31
0
def test_ellipse():
    p1 = Point(0, 0)
    p2 = Point(1, 1)
    p3 = Point(x1, x2)
    p4 = Point(0, 1)
    p5 = Point(-1, 0)

    e1 = Ellipse(p1, 1, 1)
    e2 = Ellipse(p2, half, 1)
    e3 = Ellipse(p1, y1, y1)
    c1 = Circle(p1, 1)
    c2 = Circle(p2,1)
    c3 = Circle(Point(sqrt(2),sqrt(2)),1)

    # Test creation with three points
    cen, rad = Point(3*half, 2), 5*half
    assert Circle(Point(0,0), Point(3,0), Point(0,4)) == Circle(cen, rad)
    raises(GeometryError, "Circle(Point(0,0), Point(1,1), Point(2,2))")

    # Basic Stuff
    assert e1 == c1
    assert e1 != e2
    assert p4 in e1
    assert p2 not in e2
    assert e1.area == pi
    assert e2.area == pi/2
    assert e3.area == pi*(y1**2)
    assert c1.area == e1.area
    assert c1.circumference == e1.circumference
    assert e3.circumference == 2*pi*y1

    # with generic symbols, the hradius is assumed to contain the major radius
    M = Symbol('M')
    m = Symbol('m')
    c = Ellipse(p1, M, m).circumference
    _x = c.atoms(Dummy).pop()
    assert c == \
        4*M*C.Integral(sqrt((1 - _x**2*(M**2 - m**2)/M**2)/(1 - _x**2)), (_x, 0, 1))

    assert e2.arbitrary_point() in e2

    # Foci
    f1, f2 = Point(sqrt(12), 0), Point(-sqrt(12), 0)
    ef = Ellipse(Point(0, 0), 4, 2)
    assert ef.foci in [(f1, f2), (f2, f1)]

    # Tangents
    v = sqrt(2) / 2
    p1_1 = Point(v, v)
    p1_2 = p2 + Point(half, 0)
    p1_3 = p2 + Point(0, 1)
    assert e1.tangent_lines(p4) == c1.tangent_lines(p4)
    assert e2.tangent_lines(p1_2) == [Line(p1_2, p2 + Point(half, 1))]
    assert e2.tangent_lines(p1_3) == [Line(p1_3, p2 + Point(half, 1))]
    assert c1.tangent_lines(p1_1) == [Line(p1_1, Point(0, sqrt(2)))]
    assert e2.is_tangent(Line(p1_2, p2 + Point(half, 1)))
    assert e2.is_tangent(Line(p1_3, p2 + Point(half, 1)))
    assert c1.is_tangent(Line(p1_1, Point(0, sqrt(2))))
    assert e1.is_tangent(Line(Point(0, 0), Point(1, 1))) == False

    assert Ellipse(Point(5, 5), 2, 1).tangent_lines(Point(0, 0)) == \
    [Line(Point(0, 0), Point(S(77)/25, S(132)/25)),
     Line(Point(0, 0), Point(S(33)/5, S(22)/5))]
    assert Ellipse(Point(5, 5), 2, 1).tangent_lines(Point(3, 4)) == \
    [Line(Point(3, 4), Point(3, 5)), Line(Point(3, 4), Point(5, 4))]
    assert Circle(Point(5, 5), 2).tangent_lines(Point(3, 3)) == \
    [Line(Point(3, 3), Point(3, 5)), Line(Point(3, 3), Point(5, 3))]
    assert Circle(Point(5, 5), 2).tangent_lines(Point(5 - 2*sqrt(2), 5)) == \
    [Line(Point(5 - 2*sqrt(2), 5), Point(5 - sqrt(2), 5 - sqrt(2))),
     Line(Point(5 - 2*sqrt(2), 5), Point(5 - sqrt(2), 5 + sqrt(2))),]

    # Properties
    major = 3
    minor = 1
    e4 = Ellipse(p2, minor, major)
    assert e4.focus_distance == sqrt(major**2 - minor**2)
    ecc = e4.focus_distance / major
    assert e4.eccentricity == ecc
    assert e4.periapsis == major*(1 - ecc)
    assert e4.apoapsis == major*(1 + ecc)
    # independent of orientation
    e4 = Ellipse(p2, major, minor)
    assert e4.focus_distance == sqrt(major**2 - minor**2)
    ecc = e4.focus_distance / major
    assert e4.eccentricity == ecc
    assert e4.periapsis == major*(1 - ecc)
    assert e4.apoapsis == major*(1 + ecc)

    # Intersection
    l1 = Line(Point(1, -5), Point(1, 5))
    l2 = Line(Point(-5, -1), Point(5, -1))
    l3 = Line(Point(-1, -1), Point(1, 1))
    l4 = Line(Point(-10, 0), Point(0, 10))
    pts_c1_l3 = [Point(sqrt(2)/2, sqrt(2)/2), Point(-sqrt(2)/2, -sqrt(2)/2)]

    assert intersection(e2, l4) == []
    assert intersection(c1, Point(1, 0)) == [Point(1, 0)]
    assert intersection(c1, l1) == [Point(1, 0)]
    assert intersection(c1, l2) == [Point(0, -1)]
    assert intersection(c1, l3) in [pts_c1_l3, [pts_c1_l3[1], pts_c1_l3[0]]]
    assert intersection(c1, c2) in [[(1,0), (0,1)],[(0,1),(1,0)]]
    assert intersection(c1, c3) == [(sqrt(2)/2, sqrt(2)/2)]

    # some special case intersections
    csmall = Circle(p1, 3)
    cbig = Circle(p1, 5)
    cout = Circle(Point(5, 5), 1)
    # one circle inside of another
    assert csmall.intersection(cbig) == []
    # separate circles
    assert csmall.intersection(cout) == []
    # coincident circles
    assert csmall.intersection(csmall) == csmall

    v = sqrt(2)
    t1 = Triangle(Point(0, v), Point(0, -v), Point(v, 0))
    points = intersection(t1, c1)
    assert len(points) == 4
    assert Point(0, 1) in points
    assert Point(0, -1) in points
    assert Point(v/2, v/2) in points
    assert Point(v/2, -v/2) in points

    circ = Circle(Point(0, 0), 5)
    elip = Ellipse(Point(0, 0), 5, 20)
    assert intersection(circ, elip) in \
        [[Point(5, 0), Point(-5, 0)], [Point(-5, 0), Point(5, 0)]]
    assert elip.tangent_lines(Point(0, 0)) == []
    elip = Ellipse(Point(0, 0), 3, 2)
    assert elip.tangent_lines(Point(3, 0)) == [Line(Point(3, 0), Point(3, -12))]

    e1 = Ellipse(Point(0, 0), 5, 10)
    e2 = Ellipse(Point(2, 1), 4, 8)
    a = S(53)/17
    c = 2*sqrt(3991)/17
    assert e1.intersection(e2) == [Point(a - c/8, a/2 + c), Point(a + c/8, a/2 - c)]

    # Combinations of above
    assert e3.is_tangent(e3.tangent_lines(p1 + Point(y1, 0))[0])

    e = Ellipse((1, 2), 3, 2)
    assert e.tangent_lines(Point(10, 0)) == \
       [Line(Point(10, 0), Point(1, 0)),
        Line(Point(10, 0), Point(S(14)/5, S(18)/5))]

    # encloses_point
    e = Ellipse((0, 0), 1, 2)
    assert e.encloses_point(e.center)
    assert e.encloses_point(e.center + Point(0, e.vradius - Rational(1, 10)))
    assert e.encloses_point(e.center + Point(e.hradius - Rational(1, 10), 0))
    assert e.encloses_point(e.center + Point(e.hradius, 0)) is False
    assert e.encloses_point(e.center + Point(e.hradius + Rational(1, 10), 0)) is False
    e = Ellipse((0, 0), 2, 1)
    assert e.encloses_point(e.center)
    assert e.encloses_point(e.center + Point(0, e.vradius - Rational(1, 10)))
    assert e.encloses_point(e.center + Point(e.hradius - Rational(1, 10), 0))
    assert e.encloses_point(e.center + Point(e.hradius, 0)) is False
    assert e.encloses_point(e.center + Point(e.hradius + Rational(1, 10), 0)) is False
Example #32
0
def test_ellipse_geom():
    p1 = Point(0, 0)
    p2 = Point(1, 1)
    p4 = Point(0, 1)

    e1 = Ellipse(p1, 1, 1)
    e2 = Ellipse(p2, half, 1)
    e3 = Ellipse(p1, y1, y1)
    c1 = Circle(p1, 1)
    c2 = Circle(p2, 1)
    c3 = Circle(Point(sqrt(2), sqrt(2)), 1)

    # Test creation with three points
    cen, rad = Point(3*half, 2), 5*half
    assert Circle(Point(0, 0), Point(3, 0), Point(0, 4)) == Circle(cen, rad)
    raises(
        GeometryError, lambda: Circle(Point(0, 0), Point(1, 1), Point(2, 2)))

    raises(ValueError, lambda: Ellipse(None, None, None, 1))
    raises(GeometryError, lambda: Circle(Point(0, 0)))

    # Basic Stuff
    assert Ellipse(None, 1, 1).center == Point(0, 0)
    assert e1 == c1
    assert e1 != e2
    assert p4 in e1
    assert p2 not in e2
    assert e1.area == pi
    assert e2.area == pi/2
    assert e3.area == pi*y1*abs(y1)
    assert c1.area == e1.area
    assert c1.circumference == e1.circumference
    assert e3.circumference == 2*pi*y1
    assert e1.plot_interval() == e2.plot_interval() == [t, -pi, pi]
    assert e1.plot_interval(x) == e2.plot_interval(x) == [x, -pi, pi]
    assert Ellipse(None, 1, None, 1).circumference == 2*pi
    assert c1.minor == 1
    assert c1.major == 1
    assert c1.hradius == 1
    assert c1.vradius == 1

    # Private Functions
    assert hash(c1) == hash(Circle(Point(1, 0), Point(0, 1), Point(0, -1)))
    assert c1 in e1
    assert (Line(p1, p2) in e1) is False
    assert e1.__cmp__(e1) == 0
    assert e1.__cmp__(Point(0, 0)) > 0

    # Encloses
    assert e1.encloses(Segment(Point(-0.5, -0.5), Point(0.5, 0.5))) is True
    assert e1.encloses(Line(p1, p2)) is False
    assert e1.encloses(Ray(p1, p2)) is False
    assert e1.encloses(e1) is False
    assert e1.encloses(
        Polygon(Point(-0.5, -0.5), Point(-0.5, 0.5), Point(0.5, 0.5))) is True
    assert e1.encloses(RegularPolygon(p1, 0.5, 3)) is True
    assert e1.encloses(RegularPolygon(p1, 5, 3)) is False
    assert e1.encloses(RegularPolygon(p2, 5, 3)) is False

    # with generic symbols, the hradius is assumed to contain the major radius
    M = Symbol('M')
    m = Symbol('m')
    c = Ellipse(p1, M, m).circumference
    _x = c.atoms(Dummy).pop()
    assert c == 4*M*Integral(
        sqrt((1 - _x**2*(M**2 - m**2)/M**2)/(1 - _x**2)), (_x, 0, 1))

    assert e2.arbitrary_point() in e2

    # Foci
    f1, f2 = Point(sqrt(12), 0), Point(-sqrt(12), 0)
    ef = Ellipse(Point(0, 0), 4, 2)
    assert ef.foci in [(f1, f2), (f2, f1)]

    # Tangents
    v = sqrt(2) / 2
    p1_1 = Point(v, v)
    p1_2 = p2 + Point(half, 0)
    p1_3 = p2 + Point(0, 1)
    assert e1.tangent_lines(p4) == c1.tangent_lines(p4)
    assert e2.tangent_lines(p1_2) == [Line(Point(3/2, 1), Point(3/2, 1/2))]
    assert e2.tangent_lines(p1_3) == [Line(Point(1, 2), Point(5/4, 2))]
    assert c1.tangent_lines(p1_1) != [Line(p1_1, Point(0, sqrt(2)))]
    assert c1.tangent_lines(p1) == []
    assert e2.is_tangent(Line(p1_2, p2 + Point(half, 1)))
    assert e2.is_tangent(Line(p1_3, p2 + Point(half, 1)))
    assert c1.is_tangent(Line(p1_1, Point(0, sqrt(2))))
    assert e1.is_tangent(Line(Point(0, 0), Point(1, 1))) is False
    assert c1.is_tangent(e1) is False
    assert c1.is_tangent(Ellipse(Point(2, 0), 1, 1)) is True
    assert c1.is_tangent(
        Polygon(Point(1, 1), Point(1, -1), Point(2, 0))) is True
    assert c1.is_tangent(
        Polygon(Point(1, 1), Point(1, 0), Point(2, 0))) is False
    assert Circle(Point(5, 5), 3).is_tangent(Circle(Point(0, 5), 1)) is False

    assert Ellipse(Point(5, 5), 2, 1).tangent_lines(Point(0, 0)) == \
        [Line(Point(0, 0), Point(77/25, 132/25)),
     Line(Point(0, 0), Point(33/5, 22/5))]
    assert Ellipse(Point(5, 5), 2, 1).tangent_lines(Point(3, 4)) == \
        [Line(Point(3, 4), Point(4, 4)), Line(Point(3, 4), Point(3, 5))]
    assert Circle(Point(5, 5), 2).tangent_lines(Point(3, 3)) == \
        [Line(Point(3, 3), Point(4, 3)), Line(Point(3, 3), Point(3, 4))]
    assert Circle(Point(5, 5), 2).tangent_lines(Point(5 - 2*sqrt(2), 5)) == \
        [Line(Point(5 - 2*sqrt(2), 5), Point(5 - sqrt(2), 5 - sqrt(2))),
     Line(Point(5 - 2*sqrt(2), 5), Point(5 - sqrt(2), 5 + sqrt(2))), ]

    e = Ellipse(Point(0, 0), 2, 1)
    assert e.normal_lines(Point(0, 0)) == \
        [Line(Point(0, 0), Point(0, 1)), Line(Point(0, 0), Point(1, 0))]
    assert e.normal_lines(Point(1, 0)) == \
        [Line(Point(0, 0), Point(1, 0))]
    assert e.normal_lines((0, 1)) == \
        [Line(Point(0, 0), Point(0, 1))]
    assert e.normal_lines(Point(1, 1), 2) == [
        Line(Point(-51/26, -1/5), Point(-25/26, 17/83)),
        Line(Point(28/29, -7/8), Point(57/29, -9/2))]
    # test the failure of Poly.intervals and checks a point on the boundary
    p = Point(sqrt(3), S.Half)
    assert p in e
    assert e.normal_lines(p, 2) == [
        Line(Point(-341/171, -1/13), Point(-170/171, 5/64)),
        Line(Point(26/15, -1/2), Point(41/15, -43/26))]
    # be sure to use the slope that isn't undefined on boundary
    e = Ellipse((0, 0), 2, 2*sqrt(3)/3)
    assert e.normal_lines((1, 1), 2) == [
        Line(Point(-64/33, -20/71), Point(-31/33, 2/13)),
        Line(Point(1, -1), Point(2, -4))]
    # general ellipse fails except under certain conditions
    e = Ellipse((0, 0), x, 1)
    assert e.normal_lines((x + 1, 0)) == [Line(Point(0, 0), Point(1, 0))]
    raises(NotImplementedError, lambda: e.normal_lines((x + 1, 1)))


    # Properties
    major = 3
    minor = 1
    e4 = Ellipse(p2, minor, major)
    assert e4.focus_distance == sqrt(major**2 - minor**2)
    ecc = e4.focus_distance / major
    assert e4.eccentricity == ecc
    assert e4.periapsis == major*(1 - ecc)
    assert e4.apoapsis == major*(1 + ecc)
    # independent of orientation
    e4 = Ellipse(p2, major, minor)
    assert e4.focus_distance == sqrt(major**2 - minor**2)
    ecc = e4.focus_distance / major
    assert e4.eccentricity == ecc
    assert e4.periapsis == major*(1 - ecc)
    assert e4.apoapsis == major*(1 + ecc)

    # Intersection
    l1 = Line(Point(1, -5), Point(1, 5))
    l2 = Line(Point(-5, -1), Point(5, -1))
    l3 = Line(Point(-1, -1), Point(1, 1))
    l4 = Line(Point(-10, 0), Point(0, 10))
    pts_c1_l3 = [Point(sqrt(2)/2, sqrt(2)/2), Point(-sqrt(2)/2, -sqrt(2)/2)]

    assert intersection(e2, l4) == []
    assert intersection(c1, Point(1, 0)) == [Point(1, 0)]
    assert intersection(c1, l1) == [Point(1, 0)]
    assert intersection(c1, l2) == [Point(0, -1)]
    assert intersection(c1, l3) in [pts_c1_l3, [pts_c1_l3[1], pts_c1_l3[0]]]
    assert intersection(c1, c2) == [Point(0, 1), Point(1, 0)]
    assert intersection(c1, c3) == [Point(sqrt(2)/2, sqrt(2)/2)]
    assert e1.intersection(l1) == [Point(1, 0)]
    assert e2.intersection(l4) == []
    assert e1.intersection(Circle(Point(0, 2), 1)) == [Point(0, 1)]
    assert e1.intersection(Circle(Point(5, 0), 1)) == []
    assert e1.intersection(Ellipse(Point(2, 0), 1, 1)) == [Point(1, 0)]
    assert e1.intersection(Ellipse(Point(5, 0), 1, 1,)) == []
    assert e1.intersection(Point(2, 0)) == []
    assert e1.intersection(e1) == e1

    # some special case intersections
    csmall = Circle(p1, 3)
    cbig = Circle(p1, 5)
    cout = Circle(Point(5, 5), 1)
    # one circle inside of another
    assert csmall.intersection(cbig) == []
    # separate circles
    assert csmall.intersection(cout) == []
    # coincident circles
    assert csmall.intersection(csmall) == csmall

    v = sqrt(2)
    t1 = Triangle(Point(0, v), Point(0, -v), Point(v, 0))
    points = intersection(t1, c1)
    assert len(points) == 4
    assert Point(0, 1) in points
    assert Point(0, -1) in points
    assert Point(v/2, v/2) in points
    assert Point(v/2, -v/2) in points

    circ = Circle(Point(0, 0), 5)
    elip = Ellipse(Point(0, 0), 5, 20)
    assert intersection(circ, elip) in \
        [[Point(5, 0), Point(-5, 0)], [Point(-5, 0), Point(5, 0)]]
    assert elip.tangent_lines(Point(0, 0)) == []
    elip = Ellipse(Point(0, 0), 3, 2)
    assert elip.tangent_lines(Point(3, 0)) == \
        [Line(Point(3, 0), Point(3, -12))]

    e1 = Ellipse(Point(0, 0), 5, 10)
    e2 = Ellipse(Point(2, 1), 4, 8)
    a = 53/17
    c = 2*sqrt(3991)/17
    ans = [Point(a - c/8, a/2 + c), Point(a + c/8, a/2 - c)]
    assert e1.intersection(e2) == ans
    e2 = Ellipse(Point(x, y), 4, 8)
    c = sqrt(3991)
    ans = [Point(-c/68 + a, 2*c/17 + a/2), Point(c/68 + a, -2*c/17 + a/2)]
    assert [p.subs({x: 2, y:1}) for p in e1.intersection(e2)] == ans

    # Combinations of above
    assert e3.is_tangent(e3.tangent_lines(p1 + Point(y1, 0))[0])

    e = Ellipse((1, 2), 3, 2)
    assert e.tangent_lines(Point(10, 0)) == \
        [Line(Point(10, 0), Point(1, 0)),
        Line(Point(10, 0), Point(14/5, 18/5))]

    # encloses_point
    e = Ellipse((0, 0), 1, 2)
    assert e.encloses_point(e.center)
    assert e.encloses_point(e.center + Point(0, e.vradius - Rational(1, 10)))
    assert e.encloses_point(e.center + Point(e.hradius - Rational(1, 10), 0))
    assert e.encloses_point(e.center + Point(e.hradius, 0)) is False
    assert e.encloses_point(
        e.center + Point(e.hradius + Rational(1, 10), 0)) is False
    e = Ellipse((0, 0), 2, 1)
    assert e.encloses_point(e.center)
    assert e.encloses_point(e.center + Point(0, e.vradius - Rational(1, 10)))
    assert e.encloses_point(e.center + Point(e.hradius - Rational(1, 10), 0))
    assert e.encloses_point(e.center + Point(e.hradius, 0)) is False
    assert e.encloses_point(
        e.center + Point(e.hradius + Rational(1, 10), 0)) is False
    assert c1.encloses_point(Point(1, 0)) is False
    assert c1.encloses_point(Point(0.3, 0.4)) is True

    assert e.scale(2, 3) == Ellipse((0, 0), 4, 3)
    assert e.scale(3, 6) == Ellipse((0, 0), 6, 6)
    assert e.rotate(pi) == e
    assert e.rotate(pi, (1, 2)) == Ellipse(Point(2, 4), 2, 1)
    raises(NotImplementedError, lambda: e.rotate(pi/3))

    # transformations
    c = Circle((1, 1), 2)
    assert c.scale(-1) == Circle((-1, 1), 2)
    assert c.scale(y=-1) == Circle((1, -1), 2)
    assert c.scale(2) == Ellipse((2, 1), 4, 2)