from sympy.core import Rational, S, Add, Mul, I from sympy.simplify import simplify, trigsimp from sympy.core.function import (Derivative, Function, diff) from sympy.core.numbers import pi from sympy.core.symbol import symbols from sympy.functions.elementary.miscellaneous import sqrt from sympy.functions.elementary.trigonometric import (cos, sin) from sympy.integrals.integrals import Integral from sympy.matrices.immutable import ImmutableDenseMatrix as Matrix from sympy.vector.vector import Vector, BaseVector, VectorAdd, \ VectorMul, VectorZero from sympy.vector.coordsysrect import CoordSys3D from sympy.vector.vector import Cross, Dot, cross from sympy.testing.pytest import raises from sympy.vector.kind import VectorKind from sympy.core.kind import NumberKind from sympy.testing.pytest import XFAIL C = CoordSys3D('C') i, j, k = C.base_vectors() a, b, c = symbols('a b c') def test_cross(): v1 = C.x * i + C.z * C.z * j v2 = C.x * i + C.y * j + C.z * k assert Cross(v1, v2) == Cross(C.x*C.i + C.z**2*C.j, C.x*C.i + C.y*C.j + C.z*C.k) assert Cross(v1, v2).doit() == C.z**3*C.i + (-C.x*C.z)*C.j + (C.x*C.y - C.x*C.z**2)*C.k assert cross(v1, v2) == C.z**3*C.i + (-C.x*C.z)*C.j + (C.x*C.y - C.x*C.z**2)*C.k assert Cross(v1, v2) == -Cross(v2, v1) # XXX: Cannot use Cross here. See XFAIL test below: assert cross(v1, v2) + cross(v2, v1) == Vector.zero @XFAIL def test_cross_xfail(): v1 = C.x * i + C.z * C.z * j v2 = C.x * i + C.y * j + C.z * k assert Cross(v1, v2) + Cross(v2, v1) == Vector.zero def test_dot(): v1 = C.x * i + C.z * C.z * j v2 = C.x * i + C.y * j + C.z * k assert Dot(v1, v2) == Dot(C.x*C.i + C.z**2*C.j, C.x*C.i + C.y*C.j + C.z*C.k) assert Dot(v1, v2).doit() == C.x**2 + C.y*C.z**2 assert Dot(v2, v1).doit() == C.x**2 + C.y*C.z**2 assert Dot(v1, v2) == Dot(v2, v1) def test_vector_sympy(): """ Test whether the Vector framework confirms to the hashing and equality testing properties of SymPy. """ v1 = 3*j assert v1 == j*3 assert v1.components == {j: 3} v2 = 3*i + 4*j + 5*k v3 = 2*i + 4*j + i + 4*k + k assert v3 == v2 assert v3.__hash__() == v2.__hash__() def test_kind(): assert C.i.kind is VectorKind(NumberKind) assert C.j.kind is VectorKind(NumberKind) assert C.k.kind is VectorKind(NumberKind) assert C.x.kind is NumberKind assert C.y.kind is NumberKind assert C.z.kind is NumberKind assert Mul._kind_dispatcher(NumberKind, VectorKind(NumberKind)) is VectorKind(NumberKind) assert Mul(2, C.i).kind is VectorKind(NumberKind) v1 = C.x * i + C.z * C.z * j v2 = C.x * i + C.y * j + C.z * k assert v1.kind is VectorKind(NumberKind) assert v2.kind is VectorKind(NumberKind) assert (v1 + v2).kind is VectorKind(NumberKind) assert Add(v1, v2).kind is VectorKind(NumberKind) assert Cross(v1, v2).doit().kind is VectorKind(NumberKind) assert VectorAdd(v1, v2).kind is VectorKind(NumberKind) assert VectorMul(2, v1).kind is VectorKind(NumberKind) assert VectorZero().kind is VectorKind(NumberKind) assert v1.projection(v2).kind is VectorKind(NumberKind) assert v2.projection(v1).kind is VectorKind(NumberKind) def test_vectoradd(): assert isinstance(Add(C.i, C.j), VectorAdd) v1 = C.x * i + C.z * C.z * j v2 = C.x * i + C.y * j + C.z * k assert isinstance(Add(v1, v2), VectorAdd) # https://github.com/sympy/sympy/issues/26121 E = Matrix([C.i, C.j, C.k]).T a = Matrix([1, 2, 3]) av = E*a assert av[0].kind == VectorKind() assert isinstance(av[0], VectorAdd) def test_vector(): assert isinstance(i, BaseVector) assert i != j assert j != k assert k != i assert i - i == Vector.zero assert i + Vector.zero == i assert i - Vector.zero == i assert Vector.zero != 0 assert -Vector.zero == Vector.zero v1 = a*i + b*j + c*k v2 = a**2*i + b**2*j + c**2*k v3 = v1 + v2 v4 = 2 * v1 v5 = a * i assert isinstance(v1, VectorAdd) assert v1 - v1 == Vector.zero assert v1 + Vector.zero == v1 assert v1.dot(i) == a assert v1.dot(j) == b assert v1.dot(k) == c assert i.dot(v2) == a**2 assert j.dot(v2) == b**2 assert k.dot(v2) == c**2 assert v3.dot(i) == a**2 + a assert v3.dot(j) == b**2 + b assert v3.dot(k) == c**2 + c assert v1 + v2 == v2 + v1 assert v1 - v2 == -1 * (v2 - v1) assert a * v1 == v1 * a assert isinstance(v5, VectorMul) assert v5.base_vector == i assert v5.measure_number == a assert isinstance(v4, Vector) assert isinstance(v4, VectorAdd) assert isinstance(v4, Vector) assert isinstance(Vector.zero, VectorZero) assert isinstance(Vector.zero, Vector) assert isinstance(v1 * 0, VectorZero) assert v1.to_matrix(C) == Matrix([[a], [b], [c]]) assert i.components == {i: 1} assert v5.components == {i: a} assert v1.components == {i: a, j: b, k: c} assert VectorAdd(v1, Vector.zero) == v1 assert VectorMul(a, v1) == v1*a assert VectorMul(1, i) == i assert VectorAdd(v1, Vector.zero) == v1 assert VectorMul(0, Vector.zero) == Vector.zero raises(TypeError, lambda: v1.outer(1)) raises(TypeError, lambda: v1.dot(1)) def test_vector_magnitude_normalize(): assert Vector.zero.magnitude() == 0 assert Vector.zero.normalize() == Vector.zero assert i.magnitude() == 1 assert j.magnitude() == 1 assert k.magnitude() == 1 assert i.normalize() == i assert j.normalize() == j assert k.normalize() == k v1 = a * i assert v1.normalize() == (a/sqrt(a**2))*i assert v1.magnitude() == sqrt(a**2) v2 = a*i + b*j + c*k assert v2.magnitude() == sqrt(a**2 + b**2 + c**2) assert v2.normalize() == v2 / v2.magnitude() v3 = i + j assert v3.normalize() == (sqrt(2)/2)*C.i + (sqrt(2)/2)*C.j def test_vector_simplify(): A, s, k, m = symbols('A, s, k, m') test1 = (1 / a + 1 / b) * i assert (test1 & i) != (a + b) / (a * b) test1 = simplify(test1) assert (test1 & i) == (a + b) / (a * b) assert test1.simplify() == simplify(test1) test2 = (A**2 * s**4 / (4 * pi * k * m**3)) * i test2 = simplify(test2) assert (test2 & i) == (A**2 * s**4 / (4 * pi * k * m**3)) test3 = ((4 + 4 * a - 2 * (2 + 2 * a)) / (2 + 2 * a)) * i test3 = simplify(test3) assert (test3 & i) == 0 test4 = ((-4 * a * b**2 - 2 * b**3 - 2 * a**2 * b) / (a + b)**2) * i test4 = simplify(test4) assert (test4 & i) == -2 * b v = (sin(a)+cos(a))**2*i - j assert trigsimp(v) == (2*sin(a + pi/4)**2)*i + (-1)*j assert trigsimp(v) == v.trigsimp() assert simplify(Vector.zero) == Vector.zero def test_vector_equals(): assert (2*i).equals(j) is False assert i.equals(i) is True # https://github.com/sympy/sympy/issues/25915 A = (sqrt(2) + sqrt(6)) / sqrt(sqrt(3) + 2) assert (A*i).equals(2*i) is True assert (A*i).equals(3*i) is False # Test comparing vectors in different coordinate systems D = C.orient_new_axis('D', pi/2, C.k) assert (D.i).equals(C.j) is True assert (D.i).equals(C.i) is False def test_vector_conjugate(): # https://github.com/sympy/sympy/issues/27094 assert (I*i + (1 + I)*j + 2*k).conjugate() == -I*i + (1 - I)*j + 2*k def test_vector_dot(): assert i.dot(Vector.zero) == 0 assert Vector.zero.dot(i) == 0 assert i & Vector.zero == 0 assert i.dot(i) == 1 assert i.dot(j) == 0 assert i.dot(k) == 0 assert i & i == 1 assert i & j == 0 assert i & k == 0 assert j.dot(i) == 0 assert j.dot(j) == 1 assert j.dot(k) == 0 assert j & i == 0 assert j & j == 1 assert j & k == 0 assert k.dot(i) == 0 assert k.dot(j) == 0 assert k.dot(k) == 1 assert k & i == 0 assert k & j == 0 assert k & k == 1 raises(TypeError, lambda: k.dot(1)) def test_vector_cross(): assert i.cross(Vector.zero) == Vector.zero assert Vector.zero.cross(i) == Vector.zero assert i.cross(i) == Vector.zero assert i.cross(j) == k assert i.cross(k) == -j assert i ^ i == Vector.zero assert i ^ j == k assert i ^ k == -j assert j.cross(i) == -k assert j.cross(j) == Vector.zero assert j.cross(k) == i assert j ^ i == -k assert j ^ j == Vector.zero assert j ^ k == i assert k.cross(i) == j assert k.cross(j) == -i assert k.cross(k) == Vector.zero assert k ^ i == j assert k ^ j == -i assert k ^ k == Vector.zero assert k.cross(1) == Cross(k, 1) def test_projection(): v1 = i + j + k v2 = 3*i + 4*j v3 = 0*i + 0*j assert v1.projection(v1) == i + j + k assert v1.projection(v2) == Rational(7, 3)*C.i + Rational(7, 3)*C.j + Rational(7, 3)*C.k assert v1.projection(v1, scalar=True) == S.One assert v1.projection(v2, scalar=True) == Rational(7, 3) assert v3.projection(v1) == Vector.zero assert v3.projection(v1, scalar=True) == S.Zero def test_vector_diff_integrate(): f = Function('f') v = f(a)*C.i + a**2*C.j - C.k assert Derivative(v, a) == Derivative((f(a))*C.i + a**2*C.j + (-1)*C.k, a) assert (diff(v, a) == v.diff(a) == Derivative(v, a).doit() == (Derivative(f(a), a))*C.i + 2*a*C.j) assert (Integral(v, a) == (Integral(f(a), a))*C.i + (Integral(a**2, a))*C.j + (Integral(-1, a))*C.k) def test_vector_args(): raises(ValueError, lambda: BaseVector(3, C)) raises(TypeError, lambda: BaseVector(0, Vector.zero)) def test_srepr(): from sympy.printing.repr import srepr res = "CoordSys3D(Str('C'), Tuple(ImmutableDenseMatrix([[Integer(1), "\ "Integer(0), Integer(0)], [Integer(0), Integer(1), Integer(0)], "\ "[Integer(0), Integer(0), Integer(1)]]), VectorZero())).i" assert srepr(C.i) == res def test_scalar(): from sympy.vector import CoordSys3D C = CoordSys3D('C') v1 = 3*C.i + 4*C.j + 5*C.k v2 = 3*C.i - 4*C.j + 5*C.k assert v1.is_Vector is True assert v1.is_scalar is False assert (v1.dot(v2)).is_scalar is True assert (v1.cross(v2)).is_scalar is False