from sympy.core.containers import Tuple from sympy.core.numbers import (Rational, pi) from sympy.core.singleton import S from sympy.core.symbol import (Symbol, symbols) from sympy.functions.elementary.hyperbolic import asinh from sympy.functions.elementary.miscellaneous import sqrt from sympy.geometry import Curve, Line, Point, Ellipse, Ray, Segment, Circle, Polygon, RegularPolygon from sympy.testing.pytest import raises, slow def test_curve(): x = Symbol('x', real=True) s = Symbol('s') z = Symbol('z') # this curve is independent of the indicated parameter c = Curve([2*s, s**2], (z, 0, 2)) assert c.parameter == z assert c.functions == (2*s, s**2) assert c.arbitrary_point() == Point(2*s, s**2) assert c.arbitrary_point(z) == Point(2*s, s**2) # this is how it is normally used c = Curve([2*s, s**2], (s, 0, 2)) assert c.parameter == s assert c.functions == (2*s, s**2) t = Symbol('t') # the t returned as assumptions assert c.arbitrary_point() != Point(2*t, t**2) t = Symbol('t', real=True) # now t has the same assumptions so the test passes assert c.arbitrary_point() == Point(2*t, t**2) assert c.arbitrary_point(z) == Point(2*z, z**2) assert c.arbitrary_point(c.parameter) == Point(2*s, s**2) assert c.arbitrary_point(None) == Point(2*s, s**2) assert c.plot_interval() == [t, 0, 2] assert c.plot_interval(z) == [z, 0, 2] assert Curve([x, x], (x, 0, 1)).rotate(pi/2) == Curve([-x, x], (x, 0, 1)) assert Curve([x, x], (x, 0, 1)).rotate(pi/2, (1, 2)).scale(2, 3).translate( 1, 3).arbitrary_point(s) == \ Line((0, 0), (1, 1)).rotate(pi/2, (1, 2)).scale(2, 3).translate( 1, 3).arbitrary_point(s) == \ Point(-2*s + 7, 3*s + 6) raises(ValueError, lambda: Curve((s), (s, 1, 2))) raises(ValueError, lambda: Curve((x, x * 2), (1, x))) raises(ValueError, lambda: Curve((s, s + t), (s, 1, 2)).arbitrary_point()) raises(ValueError, lambda: Curve((s, s + t), (t, 1, 2)).arbitrary_point(s)) @slow def test_free_symbols(): a, b, c, d, e, f, s = symbols('a:f,s') assert Point(a, b).free_symbols == {a, b} assert Line((a, b), (c, d)).free_symbols == {a, b, c, d} assert Ray((a, b), (c, d)).free_symbols == {a, b, c, d} assert Ray((a, b), angle=c).free_symbols == {a, b, c} assert Segment((a, b), (c, d)).free_symbols == {a, b, c, d} assert Line((a, b), slope=c).free_symbols == {a, b, c} assert Curve((a*s, b*s), (s, c, d)).free_symbols == {a, b, c, d} assert Ellipse((a, b), c, d).free_symbols == {a, b, c, d} assert Ellipse((a, b), c, eccentricity=d).free_symbols == \ {a, b, c, d} assert Ellipse((a, b), vradius=c, eccentricity=d).free_symbols == \ {a, b, c, d} assert Circle((a, b), c).free_symbols == {a, b, c} assert Circle((a, b), (c, d), (e, f)).free_symbols == \ {e, d, c, b, f, a} assert Polygon((a, b), (c, d), (e, f)).free_symbols == \ {e, b, d, f, a, c} assert RegularPolygon((a, b), c, d, e).free_symbols == {e, a, b, c, d} def test_transform(): x = Symbol('x', real=True) y = Symbol('y', real=True) c = Curve((x, x**2), (x, 0, 1)) cout = Curve((2*x - 4, 3*x**2 - 10), (x, 0, 1)) pts = [Point(0, 0), Point(S.Half, Rational(1, 4)), Point(1, 1)] pts_out = [Point(-4, -10), Point(-3, Rational(-37, 4)), Point(-2, -7)] assert c.scale(2, 3, (4, 5)) == cout assert [c.subs(x, xi/2) for xi in Tuple(0, 1, 2)] == pts assert [cout.subs(x, xi/2) for xi in Tuple(0, 1, 2)] == pts_out assert Curve((x + y, 3*x), (x, 0, 1)).subs(y, S.Half) == \ Curve((x + S.Half, 3*x), (x, 0, 1)) assert Curve((x, 3*x), (x, 0, 1)).translate(4, 5) == \ Curve((x + 4, 3*x + 5), (x, 0, 1)) def test_length(): t = Symbol('t', real=True) c1 = Curve((t, 0), (t, 0, 1)) assert c1.length == 1 c2 = Curve((t, t), (t, 0, 1)) assert c2.length == sqrt(2) c3 = Curve((t ** 2, t), (t, 2, 5)) assert c3.length == -sqrt(17) - asinh(4) / 4 + asinh(10) / 4 + 5 * sqrt(101) / 2 def test_parameter_value(): t = Symbol('t') C = Curve([2*t, t**2], (t, 0, 2)) assert C.parameter_value((2, 1), t) == {t: 1} raises(ValueError, lambda: C.parameter_value((2, 0), t)) def test_issue_17997(): t, s = symbols('t s') c = Curve((t, t**2), (t, 0, 10)) p = Curve([2*s, s**2], (s, 0, 2)) assert c(2) == Point(2, 4) assert p(1) == Point(2, 1)