107 lines
5.0 KiB
Python
107 lines
5.0 KiB
Python
from sympy.core.numbers import pi
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from sympy.core.singleton import S
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from sympy.functions.elementary.miscellaneous import sqrt
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from sympy.functions.elementary.trigonometric import (cos, sin)
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from sympy.testing.pytest import raises
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from sympy.vector.coordsysrect import CoordSys3D
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from sympy.vector.integrals import ParametricIntegral, vector_integrate
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from sympy.vector.parametricregion import ParametricRegion
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from sympy.vector.implicitregion import ImplicitRegion
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from sympy.abc import x, y, z, u, v, r, t, theta, phi
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from sympy.geometry import Point, Segment, Curve, Circle, Polygon, Plane
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C = CoordSys3D('C')
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def test_parametric_lineintegrals():
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halfcircle = ParametricRegion((4*cos(theta), 4*sin(theta)), (theta, -pi/2, pi/2))
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assert ParametricIntegral(C.x*C.y**4, halfcircle) == S(8192)/5
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curve = ParametricRegion((t, t**2, t**3), (t, 0, 1))
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field1 = 8*C.x**2*C.y*C.z*C.i + 5*C.z*C.j - 4*C.x*C.y*C.k
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assert ParametricIntegral(field1, curve) == 1
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line = ParametricRegion((4*t - 1, 2 - 2*t, t), (t, 0, 1))
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assert ParametricIntegral(C.x*C.z*C.i - C.y*C.z*C.k, line) == 3
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assert ParametricIntegral(4*C.x**3, ParametricRegion((1, t), (t, 0, 2))) == 8
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helix = ParametricRegion((cos(t), sin(t), 3*t), (t, 0, 4*pi))
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assert ParametricIntegral(C.x*C.y*C.z, helix) == -3*sqrt(10)*pi
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field2 = C.y*C.i + C.z*C.j + C.z*C.k
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assert ParametricIntegral(field2, ParametricRegion((cos(t), sin(t), t**2), (t, 0, pi))) == -5*pi/2 + pi**4/2
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def test_parametric_surfaceintegrals():
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semisphere = ParametricRegion((2*sin(phi)*cos(theta), 2*sin(phi)*sin(theta), 2*cos(phi)),\
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(theta, 0, 2*pi), (phi, 0, pi/2))
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assert ParametricIntegral(C.z, semisphere) == 8*pi
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cylinder = ParametricRegion((sqrt(3)*cos(theta), sqrt(3)*sin(theta), z), (z, 0, 6), (theta, 0, 2*pi))
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assert ParametricIntegral(C.y, cylinder) == 0
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cone = ParametricRegion((v*cos(u), v*sin(u), v), (u, 0, 2*pi), (v, 0, 1))
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assert ParametricIntegral(C.x*C.i + C.y*C.j + C.z**4*C.k, cone) == pi/3
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triangle1 = ParametricRegion((x, y), (x, 0, 2), (y, 0, 10 - 5*x))
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triangle2 = ParametricRegion((x, y), (y, 0, 10 - 5*x), (x, 0, 2))
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assert ParametricIntegral(-15.6*C.y*C.k, triangle1) == ParametricIntegral(-15.6*C.y*C.k, triangle2)
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assert ParametricIntegral(C.z, triangle1) == 10*C.z
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def test_parametric_volumeintegrals():
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cube = ParametricRegion((x, y, z), (x, 0, 1), (y, 0, 1), (z, 0, 1))
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assert ParametricIntegral(1, cube) == 1
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solidsphere1 = ParametricRegion((r*sin(phi)*cos(theta), r*sin(phi)*sin(theta), r*cos(phi)),\
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(r, 0, 2), (theta, 0, 2*pi), (phi, 0, pi))
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solidsphere2 = ParametricRegion((r*sin(phi)*cos(theta), r*sin(phi)*sin(theta), r*cos(phi)),\
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(r, 0, 2), (phi, 0, pi), (theta, 0, 2*pi))
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assert ParametricIntegral(C.x**2 + C.y**2, solidsphere1) == -256*pi/15
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assert ParametricIntegral(C.x**2 + C.y**2, solidsphere2) == 256*pi/15
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region_under_plane1 = ParametricRegion((x, y, z), (x, 0, 3), (y, 0, -2*x/3 + 2),\
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(z, 0, 6 - 2*x - 3*y))
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region_under_plane2 = ParametricRegion((x, y, z), (x, 0, 3), (z, 0, 6 - 2*x - 3*y),\
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(y, 0, -2*x/3 + 2))
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assert ParametricIntegral(C.x*C.i + C.j - 100*C.k, region_under_plane1) == \
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ParametricIntegral(C.x*C.i + C.j - 100*C.k, region_under_plane2)
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assert ParametricIntegral(2*C.x, region_under_plane2) == -9
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def test_vector_integrate():
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halfdisc = ParametricRegion((r*cos(theta), r* sin(theta)), (r, -2, 2), (theta, 0, pi))
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assert vector_integrate(C.x**2, halfdisc) == 4*pi
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assert vector_integrate(C.x, ParametricRegion((t, t**2), (t, 2, 3))) == -17*sqrt(17)/12 + 37*sqrt(37)/12
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assert vector_integrate(C.y**3*C.z, (C.x, 0, 3), (C.y, -1, 4)) == 765*C.z/4
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s1 = Segment(Point(0, 0), Point(0, 1))
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assert vector_integrate(-15*C.y, s1) == S(-15)/2
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s2 = Segment(Point(4, 3, 9), Point(1, 1, 7))
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assert vector_integrate(C.y*C.i, s2) == -6
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curve = Curve((sin(t), cos(t)), (t, 0, 2))
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assert vector_integrate(5*C.z, curve) == 10*C.z
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c1 = Circle(Point(2, 3), 6)
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assert vector_integrate(C.x*C.y, c1) == 72*pi
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c2 = Circle(Point(0, 0), Point(1, 1), Point(1, 0))
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assert vector_integrate(1, c2) == c2.circumference
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triangle = Polygon((0, 0), (1, 0), (1, 1))
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assert vector_integrate(C.x*C.i - 14*C.y*C.j, triangle) == 0
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p1, p2, p3, p4 = [(0, 0), (1, 0), (5, 1), (0, 1)]
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poly = Polygon(p1, p2, p3, p4)
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assert vector_integrate(-23*C.z, poly) == -161*C.z - 23*sqrt(17)*C.z
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point = Point(2, 3)
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assert vector_integrate(C.i*C.y - C.z, point) == ParametricIntegral(C.y*C.i, ParametricRegion((2, 3)))
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c3 = ImplicitRegion((x, y), x**2 + y**2 - 4)
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assert vector_integrate(45, c3) == 180*pi
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c4 = ImplicitRegion((x, y), (x - 3)**2 + (y - 4)**2 - 9)
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assert vector_integrate(1, c4) == 6*pi
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pl = Plane(Point(1, 1, 1), Point(2, 3, 4), Point(2, 2, 2))
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raises(ValueError, lambda: vector_integrate(C.x*C.z*C.i + C.k, pl))
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