from sympy.core.numbers import (Rational, oo) from sympy.core.singleton import S from sympy.core.symbol import symbols from sympy.functions.elementary.complexes import sign from sympy.functions.elementary.miscellaneous import sqrt from sympy.geometry.ellipse import (Circle, Ellipse) from sympy.geometry.line import (Line, Ray2D, Segment2D) from sympy.geometry.parabola import Parabola from sympy.geometry.point import (Point, Point2D) from sympy.testing.pytest import raises from sympy.abc import x, y def test_parabola_geom(): a, b = symbols('a b') p1 = Point(0, 0) p2 = Point(3, 7) p3 = Point(0, 4) p4 = Point(6, 0) p5 = Point(a, a) d1 = Line(Point(4, 0), Point(4, 9)) d2 = Line(Point(7, 6), Point(3, 6)) d3 = Line(Point(4, 0), slope=oo) d4 = Line(Point(7, 6), slope=0) d5 = Line(Point(b, a), slope=oo) d6 = Line(Point(a, b), slope=0) half = S.Half pa1 = Parabola(None, d2) pa2 = Parabola(directrix=d1) pa3 = Parabola(p1, d1) pa4 = Parabola(p2, d2) pa5 = Parabola(p2, d4) pa6 = Parabola(p3, d2) pa7 = Parabola(p2, d1) pa8 = Parabola(p4, d1) pa9 = Parabola(p4, d3) pa10 = Parabola(p5, d5) pa11 = Parabola(p5, d6) d = Line(Point(3, 7), Point(2, 9)) pa12 = Parabola(Point(7, 8), d) pa12r = Parabola(Point(7, 8).reflect(d), d) raises(ValueError, lambda: Parabola(Point(7, 8, 9), Line(Point(6, 7), Point(7, 7)))) raises(ValueError, lambda: Parabola(Point(0, 2), Line(Point(7, 2), Point(6, 2)))) raises(ValueError, lambda: Parabola(Point(7, 8), Point(3, 8))) # Basic Stuff assert pa1.focus == Point(0, 0) assert pa1.ambient_dimension == S(2) assert pa2 == pa3 assert pa4 != pa7 assert pa6 != pa7 assert pa6.focus == Point2D(0, 4) assert pa6.focal_length == 1 assert pa6.p_parameter == -1 assert pa6.vertex == Point2D(0, 5) assert pa6.eccentricity == 1 assert pa7.focus == Point2D(3, 7) assert pa7.focal_length == half assert pa7.p_parameter == -half assert pa7.vertex == Point2D(7*half, 7) assert pa4.focal_length == half assert pa4.p_parameter == half assert pa4.vertex == Point2D(3, 13*half) assert pa8.focal_length == 1 assert pa8.p_parameter == 1 assert pa8.vertex == Point2D(5, 0) assert pa4.focal_length == pa5.focal_length assert pa4.p_parameter == pa5.p_parameter assert pa4.vertex == pa5.vertex assert pa4.equation() == pa5.equation() assert pa8.focal_length == pa9.focal_length assert pa8.p_parameter == pa9.p_parameter assert pa8.vertex == pa9.vertex assert pa8.equation() == pa9.equation() assert pa10.focal_length == pa11.focal_length == sqrt((a - b) ** 2) / 2 # if a, b real == abs(a - b)/2 assert pa11.vertex == Point(*pa10.vertex[::-1]) == Point(a, a - sqrt((a - b)**2)*sign(a - b)/2) # change axis x->y, y->x on pa10 aos = pa12.axis_of_symmetry assert aos == Line(Point(7, 8), Point(5, 7)) assert pa12.directrix == Line(Point(3, 7), Point(2, 9)) assert pa12.directrix.angle_between(aos) == S.Pi/2 assert pa12.eccentricity == 1 assert pa12.equation(x, y) == (x - 7)**2 + (y - 8)**2 - (-2*x - y + 13)**2/5 assert pa12.focal_length == 9*sqrt(5)/10 assert pa12.focus == Point(7, 8) assert pa12.p_parameter == 9*sqrt(5)/10 assert pa12.vertex == Point2D(S(26)/5, S(71)/10) assert pa12r.focal_length == 9*sqrt(5)/10 assert pa12r.focus == Point(-S(1)/5, S(22)/5) assert pa12r.p_parameter == -9*sqrt(5)/10 assert pa12r.vertex == Point(S(8)/5, S(53)/10) def test_parabola_intersection(): l1 = Line(Point(1, -2), Point(-1,-2)) l2 = Line(Point(1, 2), Point(-1,2)) l3 = Line(Point(1, 0), Point(-1,0)) p1 = Point(0,0) p2 = Point(0, -2) p3 = Point(120, -12) parabola1 = Parabola(p1, l1) # parabola with parabola assert parabola1.intersection(parabola1) == [parabola1] assert parabola1.intersection(Parabola(p1, l2)) == [Point2D(-2, 0), Point2D(2, 0)] assert parabola1.intersection(Parabola(p2, l3)) == [Point2D(0, -1)] assert parabola1.intersection(Parabola(Point(16, 0), l1)) == [Point2D(8, 15)] assert parabola1.intersection(Parabola(Point(0, 16), l1)) == [Point2D(-6, 8), Point2D(6, 8)] assert parabola1.intersection(Parabola(p3, l3)) == [] # parabola with point assert parabola1.intersection(p1) == [] assert parabola1.intersection(Point2D(0, -1)) == [Point2D(0, -1)] assert parabola1.intersection(Point2D(4, 3)) == [Point2D(4, 3)] # parabola with line assert parabola1.intersection(Line(Point2D(-7, 3), Point(12, 3))) == [Point2D(-4, 3), Point2D(4, 3)] assert parabola1.intersection(Line(Point(-4, -1), Point(4, -1))) == [Point(0, -1)] assert parabola1.intersection(Line(Point(2, 0), Point(0, -2))) == [Point2D(2, 0)] raises(TypeError, lambda: parabola1.intersection(Line(Point(0, 0, 0), Point(1, 1, 1)))) # parabola with segment assert parabola1.intersection(Segment2D((-4, -5), (4, 3))) == [Point2D(0, -1), Point2D(4, 3)] assert parabola1.intersection(Segment2D((0, -5), (0, 6))) == [Point2D(0, -1)] assert parabola1.intersection(Segment2D((-12, -65), (14, -68))) == [] # parabola with ray assert parabola1.intersection(Ray2D((-4, -5), (4, 3))) == [Point2D(0, -1), Point2D(4, 3)] assert parabola1.intersection(Ray2D((0, 7), (1, 14))) == [Point2D(14 + 2*sqrt(57), 105 + 14*sqrt(57))] assert parabola1.intersection(Ray2D((0, 7), (0, 14))) == [] # parabola with ellipse/circle assert parabola1.intersection(Circle(p1, 2)) == [Point2D(-2, 0), Point2D(2, 0)] assert parabola1.intersection(Circle(p2, 1)) == [Point2D(0, -1)] assert parabola1.intersection(Ellipse(p2, 2, 1)) == [Point2D(0, -1)] assert parabola1.intersection(Ellipse(Point(0, 19), 5, 7)) == [] assert parabola1.intersection(Ellipse((0, 3), 12, 4)) == [ Point2D(0, -1), Point2D(-4*sqrt(17)/3, Rational(59, 9)), Point2D(4*sqrt(17)/3, Rational(59, 9))] # parabola with unsupported type raises(TypeError, lambda: parabola1.intersection(2))