def test_ellipse_random_point():
e3 = Ellipse(Point(0, 0), y1, y1)
rx, ry = Symbol('rx'), Symbol('ry')
for _ in range(5):
r = e3.random_point()
# substitution should give zero*y1**2
assert e3.equation(rx, ry).subs(zip((rx, ry), r.args)).equals(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, 0.5, 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)
pytest.raises(ValueError, lambda: e3.arbitrary_point(y1))
pytest.raises(ValueError, lambda: e3.arbitrary_point(object()))
assert e1.ambient_dimension == 2
# Test creation with three points
cen, rad = Point(1.5, 2), Rational(5, 2)
assert Circle(Point(0, 0), Point(3, 0), Point(0, 4)) == Circle(cen, rad)
pytest.raises(GeometryError,
lambda: Circle(Point(0, 0), Point(1, 1), Point(2, 2)))
pytest.raises(ValueError, lambda: Ellipse(None, None, None, 1))
pytest.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 # issue sympy/sympy#12303
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
# 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(0.5, 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 not c1.tangent_lines(p1)
assert e2.is_tangent(Line(p1_2, p2 + Point(0.5, 1)))
assert e2.is_tangent(Line(p1_3, p2 + Point(0.5, 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), Rational(1, 2))
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))]
pytest.raises(NotImplementedError, lambda: e.normal_lines((x + 1, 1)))
assert (c1.normal_lines(Point(1, 1)) == [
Line(Point(-sqrt(2) / 2, -sqrt(2) / 2),
Point(-sqrt(2) / 2 + 1, -sqrt(2) / 2 + 1)),
Line(Point(sqrt(2) / 2, -sqrt(2) / 2),
Point(sqrt(2) / 2 + 1, -1 - sqrt(2) / 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
assert e2.intersection(e2) == e2
assert e2.intersection(Circle(Point(0, 0), 10)) == []
pytest.raises(NotImplementedError,
lambda: e2.intersection(Curve((t**2, t), (t, 0, 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 not 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)
pytest.raises(NotImplementedError, lambda: e.rotate(pi / 3))
# Circle rotation tests (issue sympy/sympy#11743)
cir = Circle(Point(1, 0), 1)
assert cir.rotate(pi / 2) == Circle(Point(0, 1), 1)
assert cir.rotate(pi / 3) == Circle(Point(Rational(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(Rational(1, 2) + sqrt(3) / 2,
Rational(1, 2) + sqrt(3) / 2), 1)
# 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)
e1 = Ellipse(Point(1, 0), 3, 2)
assert (e1.evolute() == root(4, 3) * y**Rational(2, 3) +
(3 * x - 3)**Rational(2, 3) - root(25, 3))
e1 = Ellipse(Point(0, 0), 3, 2)
p1 = e1.random_point(seed=0)
assert p1.evalf(2) == Point(2.0664, 1.4492)
assert Ellipse((1, 0), 2, 1).rotate(pi / 2) == Ellipse(Point(0, 1), 1, 2)