def test_locatenew_point():
"""
Tests Point class, and locate_new method in CoordSysCartesian.
"""
A = CoordSysCartesian('A')
assert isinstance(A.origin, Point)
v = a * A.i + b * A.j + c * A.k
C = A.locate_new('C', v)
assert C.origin.position_wrt(A) == \
C.position_wrt(A) == \
C.origin.position_wrt(A.origin) == v
assert A.origin.position_wrt(C) == \
A.position_wrt(C) == \
A.origin.position_wrt(C.origin) == -v
assert A.origin.express_coordinates(C) == (-a, -b, -c)
p = A.origin.locate_new('p', -v)
assert p.express_coordinates(A) == (-a, -b, -c)
assert p.position_wrt(C.origin) == p.position_wrt(C) == \
-2 * v
p1 = p.locate_new('p1', 2 * v)
assert p1.position_wrt(C.origin) == Vector.zero
assert p1.express_coordinates(C) == (0, 0, 0)
p2 = p.locate_new('p2', A.i)
assert p1.position_wrt(p2) == 2 * v - A.i
assert p2.express_coordinates(C) == (-2 * a + 1, -2 * b, -2 * c)
def test_locatenew_point():
"""
Tests Point class, and locate_new method in CoordSysCartesian.
"""
A = CoordSysCartesian('A')
assert isinstance(A.origin, Point)
v = a*A.i + b*A.j + c*A.k
C = A.locate_new('C', v)
assert C.origin.position_wrt(A) == \
C.position_wrt(A) == \
C.origin.position_wrt(A.origin) == v
assert A.origin.position_wrt(C) == \
A.position_wrt(C) == \
A.origin.position_wrt(C.origin) == -v
assert A.origin.express_coordinates(C) == (-a, -b, -c)
p = A.origin.locate_new('p', -v)
assert p.express_coordinates(A) == (-a, -b, -c)
assert p.position_wrt(C.origin) == p.position_wrt(C) == \
-2 * v
p1 = p.locate_new('p1', 2*v)
assert p1.position_wrt(C.origin) == Vector.zero
assert p1.express_coordinates(C) == (0, 0, 0)
p2 = p.locate_new('p2', A.i)
assert p1.position_wrt(p2) == 2*v - A.i
assert p2.express_coordinates(C) == (-2*a + 1, -2*b, -2*c)
def test_vector():
"""
Tests the effects of orientation of coordinate systems on
basic vector operations.
"""
N = CoordSysCartesian("N")
A = N.orient_new_axis("A", q1, N.k)
B = A.orient_new_axis("B", q2, A.i)
C = B.orient_new_axis("C", q3, B.j)
# Test to_matrix
v1 = a * N.i + b * N.j + c * N.k
assert v1.to_matrix(A) == Matrix([[a * cos(q1) + b * sin(q1)], [-a * sin(q1) + b * cos(q1)], [c]])
# Test dot
assert N.i.dot(A.i) == cos(q1)
assert N.i.dot(A.j) == -sin(q1)
assert N.i.dot(A.k) == 0
assert N.j.dot(A.i) == sin(q1)
assert N.j.dot(A.j) == cos(q1)
assert N.j.dot(A.k) == 0
assert N.k.dot(A.i) == 0
assert N.k.dot(A.j) == 0
assert N.k.dot(A.k) == 1
assert N.i.dot(A.i + A.j) == -sin(q1) + cos(q1) == (A.i + A.j).dot(N.i)
assert A.i.dot(C.i) == cos(q3)
assert A.i.dot(C.j) == 0
assert A.i.dot(C.k) == sin(q3)
assert A.j.dot(C.i) == sin(q2) * sin(q3)
assert A.j.dot(C.j) == cos(q2)
assert A.j.dot(C.k) == -sin(q2) * cos(q3)
assert A.k.dot(C.i) == -cos(q2) * sin(q3)
assert A.k.dot(C.j) == sin(q2)
assert A.k.dot(C.k) == cos(q2) * cos(q3)
# Test cross
assert N.i.cross(A.i) == sin(q1) * A.k
assert N.i.cross(A.j) == cos(q1) * A.k
assert N.i.cross(A.k) == -sin(q1) * A.i - cos(q1) * A.j
assert N.j.cross(A.i) == -cos(q1) * A.k
assert N.j.cross(A.j) == sin(q1) * A.k
assert N.j.cross(A.k) == cos(q1) * A.i - sin(q1) * A.j
assert N.k.cross(A.i) == A.j
assert N.k.cross(A.j) == -A.i
assert N.k.cross(A.k) == Vector.zero
assert N.i.cross(A.i) == sin(q1) * A.k
assert N.i.cross(A.j) == cos(q1) * A.k
assert N.i.cross(A.i + A.j) == sin(q1) * A.k + cos(q1) * A.k
assert (A.i + A.j).cross(N.i) == (-sin(q1) - cos(q1)) * N.k
assert A.i.cross(C.i) == sin(q3) * C.j
assert A.i.cross(C.j) == -sin(q3) * C.i + cos(q3) * C.k
assert A.i.cross(C.k) == -cos(q3) * C.j
assert C.i.cross(A.i) == (-sin(q3) * cos(q2)) * A.j + (-sin(q2) * sin(q3)) * A.k
assert C.j.cross(A.i) == (sin(q2)) * A.j + (-cos(q2)) * A.k
assert express(C.k.cross(A.i), C).trigsimp() == cos(q3) * C.j
def test_coordsyscartesian_equivalence():
A1 = CoordSysCartesian('A')
assert A1 == A
B = CoordSysCartesian('B')
assert A != B
assert A.locate_new('C1', A.i) == A.locate_new('C2', A.i)
assert A.orient_new_axis('C1', a, A.i) == \
A.orient_new_axis('C2', a, A.i)
def test_coordsyscartesian_equivalence():
A = CoordSysCartesian("A")
A1 = CoordSysCartesian("A")
assert A1 == A
B = CoordSysCartesian("B")
assert A != B
assert A.locate_new("C1", A.i) == A.locate_new("C2", A.i)
assert A.orient_new_axis("C1", a, A.i) == A.orient_new_axis("C2", a, A.i)
def test_coordsyscartesian_equivalence():
A = CoordSysCartesian('A')
A1 = CoordSysCartesian('A')
assert A1 == A
B = CoordSysCartesian('B')
assert A != B
assert A.locate_new('C1', A.i) == A.locate_new('C2', A.i)
assert A.orient_new_axis('C1', a, A.i) == \
A.orient_new_axis('C2', a, A.i)
def test_orient_new_methods():
N = CoordSysCartesian('N')
D = N.orient_new('D', 'Axis', [q4, N.j])
E = N.orient_new('E', 'Space', [q1, q2, q3], '123')
F = N.orient_new('F', 'Quaternion', [q1, q2, q3, q4])
G = N.orient_new('G', 'Body', [q1, q2, q3], '123')
assert D == N.orient_new_axis('D', q4, N.j)
assert E == N.orient_new_space('E', q1, q2, q3, '123')
assert F == N.orient_new_quaternion('F', q1, q2, q3, q4)
assert G == N.orient_new_body('G', q1, q2, q3, '123')
def test_differential_operators_curvilinear_system():
A = CoordSysCartesian('A')
A._set_lame_coefficient_mapping('spherical')
B = CoordSysCartesian('B')
B._set_lame_coefficient_mapping('cylindrical')
# Test for spherical coordinate system and gradient
assert gradient(3 * A.x + 4 * A.y) == 3 * A.i + 4 / A.x * A.j
assert gradient(
3 * A.x * A.z +
4 * A.y) == 3 * A.z * A.i + 4 / A.x * A.j + (3 / sin(A.y)) * A.k
assert gradient(0 * A.x + 0 * A.y + 0 * A.z) == Vector.zero
assert gradient(
A.x * A.y *
A.z) == A.y * A.z * A.i + A.z * A.j + (A.y / sin(A.y)) * A.k
# Test for spherical coordinate system and divergence
assert divergence(A.x * A.i + A.y * A.j + A.z * A.k) == \
(sin(A.y)*A.x + cos(A.y)*A.x*A.y)/(sin(A.y)*A.x**2) + 3 + 1/(sin(A.y)*A.x)
assert divergence(3*A.x*A.z*A.i + A.y*A.j + A.x*A.y*A.z*A.k) == \
(sin(A.y)*A.x + cos(A.y)*A.x*A.y)/(sin(A.y)*A.x**2) + 9*A.z + A.y/sin(A.y)
assert divergence(Vector.zero) == 0
assert divergence(0 * A.i + 0 * A.j + 0 * A.k) == 0
# Test for cylindrical coordinate system and divergence
assert divergence(B.x * B.i + B.y * B.j + B.z * B.k) == 2 + 1 / B.y
assert divergence(B.x * B.j + B.z * B.k) == 1
# Test for spherical coordinate system and divergence
assert curl(A.x*A.i + A.y*A.j + A.z*A.k) == \
(cos(A.y)*A.z/(sin(A.y)*A.x))*A.i + (-A.z/A.x)*A.j + A.y/A.x*A.k
assert curl(A.x * A.j + A.z *
A.k) == (cos(A.y) * A.z /
(sin(A.y) * A.x)) * A.i + (-A.z / A.x) * A.j + 2 * A.k
def test_orienters():
A = CoordSysCartesian('A')
axis_orienter = AxisOrienter(a, A.k)
body_orienter = BodyOrienter(a, b, c, '123')
space_orienter = SpaceOrienter(a, b, c, '123')
q_orienter = QuaternionOrienter(q1, q2, q3, q4)
assert axis_orienter.rotation_matrix(A) == Matrix([
[ cos(a), sin(a), 0],
[-sin(a), cos(a), 0],
[ 0, 0, 1]])
assert body_orienter.rotation_matrix() == Matrix([
[ cos(b)*cos(c), sin(a)*sin(b)*cos(c) + sin(c)*cos(a),
sin(a)*sin(c) - sin(b)*cos(a)*cos(c)],
[-sin(c)*cos(b), -sin(a)*sin(b)*sin(c) + cos(a)*cos(c),
sin(a)*cos(c) + sin(b)*sin(c)*cos(a)],
[ sin(b), -sin(a)*cos(b),
cos(a)*cos(b)]])
assert space_orienter.rotation_matrix() == Matrix([
[cos(b)*cos(c), sin(c)*cos(b), -sin(b)],
[sin(a)*sin(b)*cos(c) - sin(c)*cos(a),
sin(a)*sin(b)*sin(c) + cos(a)*cos(c), sin(a)*cos(b)],
[sin(a)*sin(c) + sin(b)*cos(a)*cos(c), -sin(a)*cos(c) +
sin(b)*sin(c)*cos(a), cos(a)*cos(b)]])
assert q_orienter.rotation_matrix() == Matrix([
[q1**2 + q2**2 - q3**2 - q4**2, 2*q1*q4 + 2*q2*q3,
-2*q1*q3 + 2*q2*q4],
[-2*q1*q4 + 2*q2*q3, q1**2 - q2**2 + q3**2 - q4**2,
2*q1*q2 + 2*q3*q4],
[2*q1*q3 + 2*q2*q4,
-2*q1*q2 + 2*q3*q4, q1**2 - q2**2 - q3**2 + q4**2]])
def test_orthogonalize():
C = CoordSysCartesian('C')
a, b = symbols('a b', integer=True)
i, j, k = C.base_vectors()
v1 = i + 2*j
v2 = 2*i + 3*j
v3 = 3*i + 5*j
v4 = 3*i + j
v5 = 2*i + 2*j
v6 = a*i + b*j
v7 = 4*a*i + 4*b*j
assert orthogonalize(v1, v2) == [C.i + 2*C.j, 2*C.i/5 + -C.j/5]
# from wikipedia
assert orthogonalize(v4, v5, orthonormal=True) == \
[(3*sqrt(10))*C.i/10 + (sqrt(10))*C.j/10, (-sqrt(10))*C.i/10 + (3*sqrt(10))*C.j/10]
raises(ValueError, lambda: orthogonalize(v1, v2, v3))
raises(ValueError, lambda: orthogonalize(v6, v7))
def test_orthogonalize():
C = CoordSysCartesian('C')
a, b = symbols('a b', integer=True);
i, j, k = C.base_vectors()
v1 = i + 2*j
v2 = 2*i + 3*j
v3 = 3*i + 5*j
v4 = 3*i + j
v5 = 2*i + 2*j
v6 = a*i + b*j
v7 = 4*a*i + 4*b*j
assert orthogonalize(v1, v2) == [C.i + 2*C.j, 2*C.i/5 + -C.j/5]
# from wikipedia
assert orthogonalize(v4, v5, orthonormal=True) == \
[(3*sqrt(10))*C.i/10 + (sqrt(10))*C.j/10, (-sqrt(10))*C.i/10 + (3*sqrt(10))*C.j/10]
raises(ValueError, lambda: orthogonalize(v1, v2, v3))
raises(ValueError, lambda: orthogonalize(v6, v7))
def test_func_args():
A = CoordSysCartesian('A')
assert A.x.func(*A.x.args) == A.x
expr = 3 * A.x + 4 * A.y
assert expr.func(*expr.args) == expr
assert A.i.func(*A.i.args) == A.i
v = A.x * A.i + A.y * A.j + A.z * A.k
assert v.func(*v.args) == v
assert A.origin.func(*A.origin.args) == A.origin
def test_orient_new_methods():
N = CoordSysCartesian('N')
orienter1 = AxisOrienter(q4, N.j)
orienter2 = SpaceOrienter(q1, q2, q3, '123')
orienter3 = QuaternionOrienter(q1, q2, q3, q4)
orienter4 = BodyOrienter(q1, q2, q3, '123')
D = N.orient_new('D', (orienter1, ))
E = N.orient_new('E', (orienter2, ))
F = N.orient_new('F', (orienter3, ))
G = N.orient_new('G', (orienter4, ))
assert D == N.orient_new_axis('D', q4, N.j)
assert E == N.orient_new_space('E', q1, q2, q3, '123')
assert F == N.orient_new_quaternion('F', q1, q2, q3, q4)
assert G == N.orient_new_body('G', q1, q2, q3, '123')
def test_rotation_matrix():
N = CoordSysCartesian('N')
A = N.orient_new_axis('A', q1, N.k)
B = A.orient_new_axis('B', q2, A.i)
C = B.orient_new_axis('C', q3, B.j)
D = N.orient_new_axis('D', q4, N.j)
E = N.orient_new_space('E', q1, q2, q3, '123')
F = N.orient_new_quaternion('F', q1, q2, q3, q4)
G = N.orient_new_body('G', q1, q2, q3, '123')
assert N.rotation_matrix(C) == Matrix([
[- sin(q1) * sin(q2) * sin(q3) + cos(q1) * cos(q3), - sin(q1) *
cos(q2), sin(q1) * sin(q2) * cos(q3) + sin(q3) * cos(q1)], \
[sin(q1) * cos(q3) + sin(q2) * sin(q3) * cos(q1), \
cos(q1) * cos(q2), sin(q1) * sin(q3) - sin(q2) * cos(q1) * \
cos(q3)], [- sin(q3) * cos(q2), sin(q2), cos(q2) * cos(q3)]])
test_mat = D.rotation_matrix(C) - Matrix(
[[cos(q1) * cos(q3) * cos(q4) - sin(q3) * (- sin(q4) * cos(q2) +
sin(q1) * sin(q2) * cos(q4)), - sin(q2) * sin(q4) - sin(q1) *
cos(q2) * cos(q4), sin(q3) * cos(q1) * cos(q4) + cos(q3) * \
(- sin(q4) * cos(q2) + sin(q1) * sin(q2) * cos(q4))], \
[sin(q1) * cos(q3) + sin(q2) * sin(q3) * cos(q1), cos(q1) * \
cos(q2), sin(q1) * sin(q3) - sin(q2) * cos(q1) * cos(q3)], \
[sin(q4) * cos(q1) * cos(q3) - sin(q3) * (cos(q2) * cos(q4) + \
sin(q1) * sin(q2) * \
sin(q4)), sin(q2) *
cos(q4) - sin(q1) * sin(q4) * cos(q2), sin(q3) * \
sin(q4) * cos(q1) + cos(q3) * (cos(q2) * cos(q4) + \
sin(q1) * sin(q2) * sin(q4))]])
assert test_mat.expand() == zeros(3, 3)
assert E.rotation_matrix(N) == Matrix(
[[cos(q2)*cos(q3), sin(q3)*cos(q2), -sin(q2)],
[sin(q1)*sin(q2)*cos(q3) - sin(q3)*cos(q1), \
sin(q1)*sin(q2)*sin(q3) + cos(q1)*cos(q3), sin(q1)*cos(q2)], \
[sin(q1)*sin(q3) + sin(q2)*cos(q1)*cos(q3), - \
sin(q1)*cos(q3) + sin(q2)*sin(q3)*cos(q1), cos(q1)*cos(q2)]])
assert F.rotation_matrix(N) == Matrix([[
q1**2 + q2**2 - q3**2 - q4**2,
2*q1*q4 + 2*q2*q3, -2*q1*q3 + 2*q2*q4],[ -2*q1*q4 + 2*q2*q3,
q1**2 - q2**2 + q3**2 - q4**2, 2*q1*q2 + 2*q3*q4],
[2*q1*q3 + 2*q2*q4,
-2*q1*q2 + 2*q3*q4,
q1**2 - q2**2 - q3**2 + q4**2]])
assert G.rotation_matrix(N) == Matrix([[
cos(q2)*cos(q3), sin(q1)*sin(q2)*cos(q3) + sin(q3)*cos(q1),
sin(q1)*sin(q3) - sin(q2)*cos(q1)*cos(q3)], [
-sin(q3)*cos(q2), -sin(q1)*sin(q2)*sin(q3) + cos(q1)*cos(q3),
sin(q1)*cos(q3) + sin(q2)*sin(q3)*cos(q1)],[
sin(q2), -sin(q1)*cos(q2), cos(q1)*cos(q2)]])
def test_orient_new_methods():
N = CoordSysCartesian('N')
orienter1 = AxisOrienter(q4, N.j)
orienter2 = SpaceOrienter(q1, q2, q3, '123')
orienter3 = QuaternionOrienter(q1, q2, q3, q4)
orienter4 = BodyOrienter(q1, q2, q3, '123')
D = N.orient_new('D', (orienter1, ))
E = N.orient_new('E', (orienter2, ))
F = N.orient_new('F', (orienter3, ))
G = N.orient_new('G', (orienter4, ))
assert D == N.orient_new_axis('D', q4, N.j)
assert E == N.orient_new_space('E', q1, q2, q3, '123')
assert F == N.orient_new_quaternion('F', q1, q2, q3, q4)
assert G == N.orient_new_body('G', q1, q2, q3, '123')
def test_orient_new_methods():
N = CoordSysCartesian("N")
orienter1 = AxisOrienter(q4, N.j)
orienter2 = SpaceOrienter(q1, q2, q3, "123")
orienter3 = QuaternionOrienter(q1, q2, q3, q4)
orienter4 = BodyOrienter(q1, q2, q3, "123")
D = N.orient_new("D", (orienter1,))
E = N.orient_new("E", (orienter2,))
F = N.orient_new("F", (orienter3,))
G = N.orient_new("G", (orienter4,))
assert D == N.orient_new_axis("D", q4, N.j)
assert E == N.orient_new_space("E", q1, q2, q3, "123")
assert F == N.orient_new_quaternion("F", q1, q2, q3, q4)
assert G == N.orient_new_body("G", q1, q2, q3, "123")
def test_rotation_matrix():
N = CoordSysCartesian('N')
A = N.orient_new_axis('A', q1, N.k)
B = A.orient_new_axis('B', q2, A.i)
C = B.orient_new_axis('C', q3, B.j)
D = N.orient_new_axis('D', q4, N.j)
E = N.orient_new_space('E', q1, q2, q3, '123')
F = N.orient_new_quaternion('F', q1, q2, q3, q4)
G = N.orient_new_body('G', q1, q2, q3, '123')
assert N.rotation_matrix(C) == Matrix([
[- sin(q1) * sin(q2) * sin(q3) + cos(q1) * cos(q3), - sin(q1) *
cos(q2), sin(q1) * sin(q2) * cos(q3) + sin(q3) * cos(q1)], \
[sin(q1) * cos(q3) + sin(q2) * sin(q3) * cos(q1), \
cos(q1) * cos(q2), sin(q1) * sin(q3) - sin(q2) * cos(q1) * \
cos(q3)], [- sin(q3) * cos(q2), sin(q2), cos(q2) * cos(q3)]])
test_mat = D.rotation_matrix(C) - Matrix(
[[cos(q1) * cos(q3) * cos(q4) - sin(q3) * (- sin(q4) * cos(q2) +
sin(q1) * sin(q2) * cos(q4)), - sin(q2) * sin(q4) - sin(q1) *
cos(q2) * cos(q4), sin(q3) * cos(q1) * cos(q4) + cos(q3) * \
(- sin(q4) * cos(q2) + sin(q1) * sin(q2) * cos(q4))], \
[sin(q1) * cos(q3) + sin(q2) * sin(q3) * cos(q1), cos(q1) * \
cos(q2), sin(q1) * sin(q3) - sin(q2) * cos(q1) * cos(q3)], \
[sin(q4) * cos(q1) * cos(q3) - sin(q3) * (cos(q2) * cos(q4) + \
sin(q1) * sin(q2) * \
sin(q4)), sin(q2) *
cos(q4) - sin(q1) * sin(q4) * cos(q2), sin(q3) * \
sin(q4) * cos(q1) + cos(q3) * (cos(q2) * cos(q4) + \
sin(q1) * sin(q2) * sin(q4))]])
assert test_mat.expand() == zeros(3, 3)
assert E.rotation_matrix(N) == Matrix(
[[cos(q2)*cos(q3), sin(q3)*cos(q2), -sin(q2)],
[sin(q1)*sin(q2)*cos(q3) - sin(q3)*cos(q1), \
sin(q1)*sin(q2)*sin(q3) + cos(q1)*cos(q3), sin(q1)*cos(q2)], \
[sin(q1)*sin(q3) + sin(q2)*cos(q1)*cos(q3), - \
sin(q1)*cos(q3) + sin(q2)*sin(q3)*cos(q1), cos(q1)*cos(q2)]])
assert F.rotation_matrix(N) == Matrix([[
q1**2 + q2**2 - q3**2 - q4**2,
2*q1*q4 + 2*q2*q3, -2*q1*q3 + 2*q2*q4],[ -2*q1*q4 + 2*q2*q3,
q1**2 - q2**2 + q3**2 - q4**2, 2*q1*q2 + 2*q3*q4],
[2*q1*q3 + 2*q2*q4,
-2*q1*q2 + 2*q3*q4,
q1**2 - q2**2 - q3**2 + q4**2]])
assert G.rotation_matrix(N) == Matrix([[
cos(q2)*cos(q3), sin(q1)*sin(q2)*cos(q3) + sin(q3)*cos(q1),
sin(q1)*sin(q3) - sin(q2)*cos(q1)*cos(q3)], [
-sin(q3)*cos(q2), -sin(q1)*sin(q2)*sin(q3) + cos(q1)*cos(q3),
sin(q1)*cos(q3) + sin(q2)*sin(q3)*cos(q1)],[
sin(q2), -sin(q1)*cos(q2), cos(q1)*cos(q2)]])
from sympy.vector.vector import Vector
from sympy.vector.coordsysrect import CoordSysCartesian
from sympy.vector.functions import express, matrix_to_vector
from sympy import symbols, S, sin, cos, ImmutableMatrix as Matrix
N = CoordSysCartesian('N')
q1, q2, q3, q4, q5 = symbols('q1 q2 q3 q4 q5')
A = N.orient_new_axis('A', q1, N.k)
B = A.orient_new_axis('B', q2, A.i)
C = B.orient_new_axis('C', q3, B.j)
def test_express():
assert express(Vector.zero, N) == Vector.zero
assert express(S(0), N) == S(0)
assert express(A.i, C) == cos(q3) * C.i + sin(q3) * C.k
assert express(A.j, C) == sin(q2)*sin(q3)*C.i + cos(q2)*C.j - \
sin(q2)*cos(q3)*C.k
assert express(A.k, C) == -sin(q3)*cos(q2)*C.i + sin(q2)*C.j + \
cos(q2)*cos(q3)*C.k
assert express(A.i, N) == cos(q1) * N.i + sin(q1) * N.j
assert express(A.j, N) == -sin(q1) * N.i + cos(q1) * N.j
assert express(A.k, N) == N.k
assert express(A.i, A) == A.i
assert express(A.j, A) == A.j
assert express(A.k, A) == A.k
assert express(A.i, B) == B.i
assert express(A.j, B) == cos(q2) * B.j - sin(q2) * B.k
assert express(A.k, B) == sin(q2) * B.j + cos(q2) * B.k
assert express(A.i, C) == cos(q3) * C.i + sin(q3) * C.k
assert express(A.j, C) == sin(q2)*sin(q3)*C.i + cos(q2)*C.j - \
from sympy.core.function import Derivative
from sympy.vector.vector import Vector
from sympy.vector.coordsysrect import CoordSysCartesian
from sympy.simplify import simplify
from sympy.core.symbol import symbols
from sympy.core import S
from sympy import sin, cos
from sympy.vector.functions import (curl, divergence, gradient,
is_conservative, is_solenoidal,
scalar_potential,
scalar_potential_difference)
from sympy.utilities.pytest import raises
C = CoordSysCartesian('C')
i, j, k = C.base_vectors()
x, y, z = C.base_scalars()
delop = C.delop
a, b, c, q = symbols('a b c q')
def test_del_operator():
#Tests for curl
assert (delop
^ Vector.zero == (Derivative(0, C.y) - Derivative(0, C.z)) * C.i +
(-Derivative(0, C.x) + Derivative(0, C.z)) * C.j +
(Derivative(0, C.x) - Derivative(0, C.y)) * C.k)
assert ((delop ^ Vector.zero).doit() == Vector.zero == curl(
Vector.zero, C))
assert delop.cross(Vector.zero) == delop ^ Vector.zero
assert (delop ^ i).doit() == Vector.zero
def test_coordinate_vars():
"""
Tests the coordinate variables functionality with respect to
reorientation of coordinate systems.
"""
A = CoordSysCartesian("A")
assert BaseScalar("Ax", 0, A, " ", " ") == A.x
assert BaseScalar("Ay", 1, A, " ", " ") == A.y
assert BaseScalar("Az", 2, A, " ", " ") == A.z
assert BaseScalar("Ax", 0, A, " ", " ").__hash__() == A.x.__hash__()
assert isinstance(A.x, BaseScalar) and isinstance(A.y, BaseScalar) and isinstance(A.z, BaseScalar)
assert A.scalar_map(A) == {A.x: A.x, A.y: A.y, A.z: A.z}
assert A.x.system == A
B = A.orient_new_axis("B", q, A.k)
assert B.scalar_map(A) == {B.z: A.z, B.y: -A.x * sin(q) + A.y * cos(q), B.x: A.x * cos(q) + A.y * sin(q)}
assert A.scalar_map(B) == {A.x: B.x * cos(q) - B.y * sin(q), A.y: B.x * sin(q) + B.y * cos(q), A.z: B.z}
assert express(B.x, A, variables=True) == A.x * cos(q) + A.y * sin(q)
assert express(B.y, A, variables=True) == -A.x * sin(q) + A.y * cos(q)
assert express(B.z, A, variables=True) == A.z
assert express(B.x * B.y * B.z, A, variables=True) == A.z * (-A.x * sin(q) + A.y * cos(q)) * (
A.x * cos(q) + A.y * sin(q)
)
assert (
express(B.x * B.i + B.y * B.j + B.z * B.k, A)
== (B.x * cos(q) - B.y * sin(q)) * A.i + (B.x * sin(q) + B.y * cos(q)) * A.j + B.z * A.k
)
assert simplify(express(B.x * B.i + B.y * B.j + B.z * B.k, A, variables=True)) == A.x * A.i + A.y * A.j + A.z * A.k
assert (
express(A.x * A.i + A.y * A.j + A.z * A.k, B)
== (A.x * cos(q) + A.y * sin(q)) * B.i + (-A.x * sin(q) + A.y * cos(q)) * B.j + A.z * B.k
)
assert simplify(express(A.x * A.i + A.y * A.j + A.z * A.k, B, variables=True)) == B.x * B.i + B.y * B.j + B.z * B.k
N = B.orient_new_axis("N", -q, B.k)
assert N.scalar_map(A) == {N.x: A.x, N.z: A.z, N.y: A.y}
C = A.orient_new_axis("C", q, A.i + A.j + A.k)
mapping = A.scalar_map(C)
assert (
mapping[A.x]
== 2 * C.x * cos(q) / 3
+ C.x / 3
- 2 * C.y * sin(q + pi / 6) / 3
+ C.y / 3
- 2 * C.z * cos(q + pi / 3) / 3
+ C.z / 3
)
assert (
mapping[A.y]
== -2 * C.x * cos(q + pi / 3) / 3
+ C.x / 3
+ 2 * C.y * cos(q) / 3
+ C.y / 3
- 2 * C.z * sin(q + pi / 6) / 3
+ C.z / 3
)
assert (
mapping[A.z]
== -2 * C.x * sin(q + pi / 6) / 3
+ C.x / 3
- 2 * C.y * cos(q + pi / 3) / 3
+ C.y / 3
+ 2 * C.z * cos(q) / 3
+ C.z / 3
)
D = A.locate_new("D", a * A.i + b * A.j + c * A.k)
assert D.scalar_map(A) == {D.z: A.z - c, D.x: A.x - a, D.y: A.y - b}
E = A.orient_new_axis("E", a, A.k, a * A.i + b * A.j + c * A.k)
assert A.scalar_map(E) == {A.z: E.z + c, A.x: E.x * cos(a) - E.y * sin(a) + a, A.y: E.x * sin(a) + E.y * cos(a) + b}
assert E.scalar_map(A) == {
E.x: (A.x - a) * cos(a) + (A.y - b) * sin(a),
E.y: (-A.x + a) * sin(a) + (A.y - b) * cos(a),
E.z: A.z - c,
}
F = A.locate_new("F", Vector.zero)
assert A.scalar_map(F) == {A.z: F.z, A.x: F.x, A.y: F.y}
def test_transformation_equations():
from sympy import symbols
x, y, z = symbols('x y z')
a = CoordSysCartesian('a')
# Str
a._connect_to_standard_cartesian('spherical')
assert a._transformation_equations() == (a.x * sin(a.y) * cos(a.z),
a.x * sin(a.y) * sin(a.z),
a.x * cos(a.y))
assert a.lame_coefficients() == (1, a.x, a.x * sin(a.y))
a._connect_to_standard_cartesian('cylindrical')
assert a._transformation_equations() == (a.x * cos(a.y), a.x * sin(a.y),
a.z)
assert a.lame_coefficients() == (1, a.y, 1)
a._connect_to_standard_cartesian('cartesian')
assert a._transformation_equations() == (a.x, a.y, a.z)
assert a.lame_coefficients() == (1, 1, 1)
# Variables and expressions
a._connect_to_standard_cartesian(((x, y, z), (x, y, z)))
assert a._transformation_equations() == (a.x, a.y, a.z)
assert a.lame_coefficients() == (1, 1, 1)
a._connect_to_standard_cartesian(
((x, y, z), ((x * cos(y), x * sin(y), z))))
assert a._transformation_equations() == (a.x * cos(a.y), a.x * sin(a.y),
a.z)
assert simplify(a.lame_coefficients()) == (1, sqrt(a.x**2), 1)
a._connect_to_standard_cartesian(
((x, y, z), (x * sin(y) * cos(z), x * sin(y) * sin(z), x * cos(y))))
assert a._transformation_equations() == (a.x * sin(a.y) * cos(a.z),
a.x * sin(a.y) * sin(a.z),
a.x * cos(a.y))
assert simplify(a.lame_coefficients()) == (1, sqrt(a.x**2),
sqrt(sin(a.y)**2 * a.x**2))
# Equations
a._connect_to_standard_cartesian(
(a.x * sin(a.y) * cos(a.z), a.x * sin(a.y) * sin(a.z), a.x * cos(a.y)))
assert a._transformation_equations() == (a.x * sin(a.y) * cos(a.z),
a.x * sin(a.y) * sin(a.z),
a.x * cos(a.y))
assert simplify(a.lame_coefficients()) == (1, sqrt(a.x**2),
sqrt(sin(a.y)**2 * a.x**2))
a._connect_to_standard_cartesian((a.x, a.y, a.z))
assert a._transformation_equations() == (a.x, a.y, a.z)
assert simplify(a.lame_coefficients()) == (1, 1, 1)
a._connect_to_standard_cartesian((a.x * cos(a.y), a.x * sin(a.y), a.z))
assert a._transformation_equations() == (a.x * cos(a.y), a.x * sin(a.y),
a.z)
assert simplify(a.lame_coefficients()) == (1, sqrt(a.x**2), 1)
from sympy.vector.vector import Vector
from sympy.vector.coordsysrect import CoordSysCartesian
from sympy.vector.functions import express, matrix_to_vector
from sympy import symbols, S, sin, cos, ImmutableMatrix as Matrix
N = CoordSysCartesian('N')
q1, q2, q3, q4, q5 = symbols('q1 q2 q3 q4 q5')
A = N.orient_new('A', 'Axis', [q1, N.k])
B = A.orient_new('B', 'Axis', [q2, A.i])
C = B.orient_new('C', 'Axis', [q3, B.j])
def test_express():
assert express(Vector.zero, N) == Vector.zero
assert express(S(0), N) == S(0)
assert express(A.i, C) == cos(q3) * C.i + sin(q3) * C.k
assert express(A.j, C) == sin(q2)*sin(q3)*C.i + cos(q2)*C.j - \
sin(q2)*cos(q3)*C.k
assert express(A.k, C) == -sin(q3)*cos(q2)*C.i + sin(q2)*C.j + \
cos(q2)*cos(q3)*C.k
assert express(A.i, N) == cos(q1) * N.i + sin(q1) * N.j
assert express(A.j, N) == -sin(q1) * N.i + cos(q1) * N.j
assert express(A.k, N) == N.k
assert express(A.i, A) == A.i
assert express(A.j, A) == A.j
assert express(A.k, A) == A.k
assert express(A.i, B) == B.i
assert express(A.j, B) == cos(q2) * B.j - sin(q2) * B.k
assert express(A.k, B) == sin(q2) * B.j + cos(q2) * B.k
assert express(A.i, C) == cos(q3) * C.i + sin(q3) * C.k
assert express(A.j, C) == sin(q2)*sin(q3)*C.i + cos(q2)*C.j - \
def test_coordinate_vars():
"""
Tests the coordinate variables functionality with respect to
reorientation of coordinate systems.
"""
A = CoordSysCartesian('A')
assert BaseScalar('Ax', 0, A, ' ', ' ') == A.x
assert BaseScalar('Ay', 1, A, ' ', ' ') == A.y
assert BaseScalar('Az', 2, A, ' ', ' ') == A.z
assert BaseScalar('Ax', 0, A, ' ', ' ').__hash__() == A.x.__hash__()
assert isinstance(A.x, BaseScalar) and \
isinstance(A.y, BaseScalar) and \
isinstance(A.z, BaseScalar)
assert A.scalar_map(A) == {A.x: A.x, A.y: A.y, A.z: A.z}
assert A.x.system == A
B = A.orient_new_axis('B', q, A.k)
assert B.scalar_map(A) == {
B.z: A.z,
B.y: -A.x * sin(q) + A.y * cos(q),
B.x: A.x * cos(q) + A.y * sin(q)
}
assert A.scalar_map(B) == {
A.x: B.x * cos(q) - B.y * sin(q),
A.y: B.x * sin(q) + B.y * cos(q),
A.z: B.z
}
assert express(B.x, A, variables=True) == A.x * cos(q) + A.y * sin(q)
assert express(B.y, A, variables=True) == -A.x * sin(q) + A.y * cos(q)
assert express(B.z, A, variables=True) == A.z
assert express(B.x*B.y*B.z, A, variables=True) == \
A.z*(-A.x*sin(q) + A.y*cos(q))*(A.x*cos(q) + A.y*sin(q))
assert express(B.x*B.i + B.y*B.j + B.z*B.k, A) == \
(B.x*cos(q) - B.y*sin(q))*A.i + (B.x*sin(q) + \
B.y*cos(q))*A.j + B.z*A.k
assert simplify(express(B.x*B.i + B.y*B.j + B.z*B.k, A, \
variables=True)) == \
A.x*A.i + A.y*A.j + A.z*A.k
assert express(A.x*A.i + A.y*A.j + A.z*A.k, B) == \
(A.x*cos(q) + A.y*sin(q))*B.i + \
(-A.x*sin(q) + A.y*cos(q))*B.j + A.z*B.k
assert simplify(express(A.x*A.i + A.y*A.j + A.z*A.k, B, \
variables=True)) == \
B.x*B.i + B.y*B.j + B.z*B.k
N = B.orient_new_axis('N', -q, B.k)
assert N.scalar_map(A) == \
{N.x: A.x, N.z: A.z, N.y: A.y}
C = A.orient_new_axis('C', q, A.i + A.j + A.k)
mapping = A.scalar_map(C)
assert mapping[A.x] == 2*C.x*cos(q)/3 + C.x/3 - \
2*C.y*sin(q + pi/6)/3 + C.y/3 - 2*C.z*cos(q + pi/3)/3 + C.z/3
assert mapping[A.y] == -2*C.x*cos(q + pi/3)/3 + \
C.x/3 + 2*C.y*cos(q)/3 + C.y/3 - 2*C.z*sin(q + pi/6)/3 + C.z/3
assert mapping[A.z] == -2*C.x*sin(q + pi/6)/3 + C.x/3 - \
2*C.y*cos(q + pi/3)/3 + C.y/3 + 2*C.z*cos(q)/3 + C.z/3
D = A.locate_new('D', a * A.i + b * A.j + c * A.k)
assert D.scalar_map(A) == {D.z: A.z - c, D.x: A.x - a, D.y: A.y - b}
E = A.orient_new_axis('E', a, A.k, a * A.i + b * A.j + c * A.k)
assert A.scalar_map(E) == {
A.z: E.z + c,
A.x: E.x * cos(a) - E.y * sin(a) + a,
A.y: E.x * sin(a) + E.y * cos(a) + b
}
assert E.scalar_map(A) == {
E.x: (A.x - a) * cos(a) + (A.y - b) * sin(a),
E.y: (-A.x + a) * sin(a) + (A.y - b) * cos(a),
E.z: A.z - c
}
F = A.locate_new('F', Vector.zero)
assert A.scalar_map(F) == {A.z: F.z, A.x: F.x, A.y: F.y}
from sympy.vector.coordsysrect import CoordSysCartesian
from sympy.vector.scalar import BaseScalar
from sympy import Symbol, sin, cos, pi, ImmutableMatrix as Matrix, \
symbols, simplify, sqrt, zeros
from sympy.vector.functions import express
from sympy.vector.point import Point
from sympy.vector.vector import Vector
from sympy.vector.orienters import (AxisOrienter, BodyOrienter, SpaceOrienter,
QuaternionOrienter)
A = CoordSysCartesian('A')
a, b, c, q = symbols('a b c q')
q1, q2, q3, q4 = symbols('q1 q2 q3 q4')
def test_coordsyscartesian_equivalence():
A1 = CoordSysCartesian('A')
assert A1 == A
B = CoordSysCartesian('B')
assert A != B
assert A.locate_new('C1', A.i) == A.locate_new('C2', A.i)
assert A.orient_new_axis('C1', a, A.i) == \
A.orient_new_axis('C2', a, A.i)
def test_orienters():
axis_orienter = AxisOrienter(a, A.k)
body_orienter = BodyOrienter(a, b, c, '123')
space_orienter = SpaceOrienter(a, b, c, '123')
q_orienter = QuaternionOrienter(q1, q2, q3, q4)
assert axis_orienter.rotation_matrix(A) == Matrix([[cos(a),
from sympy.vector.vector import Vector
from sympy.vector.coordsysrect import CoordSysCartesian
from sympy.simplify import simplify
from sympy.core.symbol import symbols
from sympy.core import S
from sympy import sin, cos
C = CoordSysCartesian('C')
i, j, k = C.base_vectors()
x, y, z = C.base_scalars()
delop = C.delop
a, b, c = symbols('a b c')
def test_del_operator():
#Tests for curl
assert delop ^ Vector.zero == Vector.zero
assert delop.cross(Vector.zero) == Vector.zero
assert delop ^ i == Vector.zero
assert delop.cross(2 * y**2 * j) == Vector.zero
v = x * y * z * (i + j + k)
assert delop ^ v == \
(-x*y + x*z)*i + (x*y - y*z)*j + (-x*z + y*z)*k
assert delop ^ v == delop.cross(v)
assert delop.cross(2 * x**2 * j) == 4 * x * k
#Tests for divergence
assert delop & Vector.zero == S(0)
assert delop.dot(Vector.zero) == S(0)
assert delop & i == S(0)
from sympy.vector.vector import Vector
from sympy.vector.coordsysrect import CoordSysCartesian
from sympy.vector.functions import express, matrix_to_vector, orthogonalize
from sympy import symbols, S, sqrt, sin, cos, ImmutableMatrix as Matrix
from sympy.utilities.pytest import raises
N = CoordSysCartesian('N')
q1, q2, q3, q4, q5 = symbols('q1 q2 q3 q4 q5')
A = N.orient_new_axis('A', q1, N.k)
B = A.orient_new_axis('B', q2, A.i)
C = B.orient_new_axis('C', q3, B.j)
def test_express():
assert express(Vector.zero, N) == Vector.zero
assert express(S(0), N) == S(0)
assert express(A.i, C) == cos(q3)*C.i + sin(q3)*C.k
assert express(A.j, C) == sin(q2)*sin(q3)*C.i + cos(q2)*C.j - \
sin(q2)*cos(q3)*C.k
assert express(A.k, C) == -sin(q3)*cos(q2)*C.i + sin(q2)*C.j + \
cos(q2)*cos(q3)*C.k
assert express(A.i, N) == cos(q1)*N.i + sin(q1)*N.j
assert express(A.j, N) == -sin(q1)*N.i + cos(q1)*N.j
assert express(A.k, N) == N.k
assert express(A.i, A) == A.i
assert express(A.j, A) == A.j
assert express(A.k, A) == A.k
assert express(A.i, B) == B.i
assert express(A.j, B) == cos(q2)*B.j - sin(q2)*B.k
assert express(A.k, B) == sin(q2)*B.j + cos(q2)*B.k
assert express(A.i, C) == cos(q3)*C.i + sin(q3)*C.k
def test_coordinate_vars():
"""
Tests the coordinate variables functionality with respect to
reorientation of coordinate systems.
"""
A = CoordSysCartesian('A')
# Note that the name given on the lhs is different from A.x._name
assert BaseScalar('A.x', 0, A, 'A_x', r'\mathbf{{x}_{A}}') == A.x
assert BaseScalar('A.y', 1, A, 'A_y', r'\mathbf{{y}_{A}}') == A.y
assert BaseScalar('A.z', 2, A, 'A_z', r'\mathbf{{z}_{A}}') == A.z
assert BaseScalar('A.x', 0, A, 'A_x', r'\mathbf{{x}_{A}}').__hash__() == A.x.__hash__()
assert isinstance(A.x, BaseScalar) and \
isinstance(A.y, BaseScalar) and \
isinstance(A.z, BaseScalar)
assert A.x*A.y == A.y*A.x
assert A.scalar_map(A) == {A.x: A.x, A.y: A.y, A.z: A.z}
assert A.x.system == A
assert A.x.diff(A.x) == 1
B = A.orient_new_axis('B', q, A.k)
assert B.scalar_map(A) == {B.z: A.z, B.y: -A.x*sin(q) + A.y*cos(q),
B.x: A.x*cos(q) + A.y*sin(q)}
assert A.scalar_map(B) == {A.x: B.x*cos(q) - B.y*sin(q),
A.y: B.x*sin(q) + B.y*cos(q), A.z: B.z}
assert express(B.x, A, variables=True) == A.x*cos(q) + A.y*sin(q)
assert express(B.y, A, variables=True) == -A.x*sin(q) + A.y*cos(q)
assert express(B.z, A, variables=True) == A.z
assert expand(express(B.x*B.y*B.z, A, variables=True)) == \
expand(A.z*(-A.x*sin(q) + A.y*cos(q))*(A.x*cos(q) + A.y*sin(q)))
assert express(B.x*B.i + B.y*B.j + B.z*B.k, A) == \
(B.x*cos(q) - B.y*sin(q))*A.i + (B.x*sin(q) + \
B.y*cos(q))*A.j + B.z*A.k
assert simplify(express(B.x*B.i + B.y*B.j + B.z*B.k, A, \
variables=True)) == \
A.x*A.i + A.y*A.j + A.z*A.k
assert express(A.x*A.i + A.y*A.j + A.z*A.k, B) == \
(A.x*cos(q) + A.y*sin(q))*B.i + \
(-A.x*sin(q) + A.y*cos(q))*B.j + A.z*B.k
assert simplify(express(A.x*A.i + A.y*A.j + A.z*A.k, B, \
variables=True)) == \
B.x*B.i + B.y*B.j + B.z*B.k
N = B.orient_new_axis('N', -q, B.k)
assert N.scalar_map(A) == \
{N.x: A.x, N.z: A.z, N.y: A.y}
C = A.orient_new_axis('C', q, A.i + A.j + A.k)
mapping = A.scalar_map(C)
assert mapping[A.x] == (C.x*(2*cos(q) + 1)/3 +
C.y*(-2*sin(q + pi/6) + 1)/3 +
C.z*(-2*cos(q + pi/3) + 1)/3)
assert mapping[A.y] == (C.x*(-2*cos(q + pi/3) + 1)/3 +
C.y*(2*cos(q) + 1)/3 +
C.z*(-2*sin(q + pi/6) + 1)/3)
assert mapping[A.z] == (C.x*(-2*sin(q + pi/6) + 1)/3 +
C.y*(-2*cos(q + pi/3) + 1)/3 +
C.z*(2*cos(q) + 1)/3)
D = A.locate_new('D', a*A.i + b*A.j + c*A.k)
assert D.scalar_map(A) == {D.z: A.z - c, D.x: A.x - a, D.y: A.y - b}
E = A.orient_new_axis('E', a, A.k, a*A.i + b*A.j + c*A.k)
assert A.scalar_map(E) == {A.z: E.z + c,
A.x: E.x*cos(a) - E.y*sin(a) + a,
A.y: E.x*sin(a) + E.y*cos(a) + b}
assert E.scalar_map(A) == {E.x: (A.x - a)*cos(a) + (A.y - b)*sin(a),
E.y: (-A.x + a)*sin(a) + (A.y - b)*cos(a),
E.z: A.z - c}
F = A.locate_new('F', Vector.zero)
assert A.scalar_map(F) == {A.z: F.z, A.x: F.x, A.y: F.y}
def test_coordsyscartesian_equivalence():
A = CoordSysCartesian('A')
A1 = CoordSysCartesian('A')
assert A1 == A
B = CoordSysCartesian('B')
assert A != B
def test_vector():
"""
Tests the effects of orientation of coordinate systems on
basic vector operations.
"""
N = CoordSysCartesian('N')
A = N.orient_new_axis('A', q1, N.k)
B = A.orient_new_axis('B', q2, A.i)
C = B.orient_new_axis('C', q3, B.j)
#Test to_matrix
v1 = a * N.i + b * N.j + c * N.k
assert v1.to_matrix(A) == Matrix([[a * cos(q1) + b * sin(q1)],
[-a * sin(q1) + b * cos(q1)], [c]])
#Test dot
assert N.i.dot(A.i) == cos(q1)
assert N.i.dot(A.j) == -sin(q1)
assert N.i.dot(A.k) == 0
assert N.j.dot(A.i) == sin(q1)
assert N.j.dot(A.j) == cos(q1)
assert N.j.dot(A.k) == 0
assert N.k.dot(A.i) == 0
assert N.k.dot(A.j) == 0
assert N.k.dot(A.k) == 1
assert N.i.dot(A.i + A.j) == -sin(q1) + cos(q1) == \
(A.i + A.j).dot(N.i)
assert A.i.dot(C.i) == cos(q3)
assert A.i.dot(C.j) == 0
assert A.i.dot(C.k) == sin(q3)
assert A.j.dot(C.i) == sin(q2) * sin(q3)
assert A.j.dot(C.j) == cos(q2)
assert A.j.dot(C.k) == -sin(q2) * cos(q3)
assert A.k.dot(C.i) == -cos(q2) * sin(q3)
assert A.k.dot(C.j) == sin(q2)
assert A.k.dot(C.k) == cos(q2) * cos(q3)
#Test cross
assert N.i.cross(A.i) == sin(q1) * A.k
assert N.i.cross(A.j) == cos(q1) * A.k
assert N.i.cross(A.k) == -sin(q1) * A.i - cos(q1) * A.j
assert N.j.cross(A.i) == -cos(q1) * A.k
assert N.j.cross(A.j) == sin(q1) * A.k
assert N.j.cross(A.k) == cos(q1) * A.i - sin(q1) * A.j
assert N.k.cross(A.i) == A.j
assert N.k.cross(A.j) == -A.i
assert N.k.cross(A.k) == Vector.zero
assert N.i.cross(A.i) == sin(q1) * A.k
assert N.i.cross(A.j) == cos(q1) * A.k
assert N.i.cross(A.i + A.j) == sin(q1) * A.k + cos(q1) * A.k
assert (A.i + A.j).cross(N.i) == (-sin(q1) - cos(q1)) * N.k
assert A.i.cross(C.i) == sin(q3) * C.j
assert A.i.cross(C.j) == -sin(q3) * C.i + cos(q3) * C.k
assert A.i.cross(C.k) == -cos(q3) * C.j
assert C.i.cross(A.i) == (-sin(q3)*cos(q2))*A.j + \
(-sin(q2)*sin(q3))*A.k
assert C.j.cross(A.i) == (sin(q2)) * A.j + (-cos(q2)) * A.k
assert express(C.k.cross(A.i), C).trigsimp() == cos(q3) * C.j
def test_coordsys3d():
with warnings.catch_warnings():
warnings.filterwarnings("ignore", category=SymPyDeprecationWarning)
assert CoordSysCartesian("C") == CoordSys3D("C")
def test_coordinate_vars():
"""
Tests the coordinate variables functionality with respect to
reorientation of coordinate systems.
"""
A = CoordSysCartesian('A')
# Note that the name given on the lhs is different from A.x._name
assert BaseScalar('A.x', 0, A, 'A_x', r'\mathbf{{x}_{A}}') == A.x
assert BaseScalar('A.y', 1, A, 'A_y', r'\mathbf{{y}_{A}}') == A.y
assert BaseScalar('A.z', 2, A, 'A_z', r'\mathbf{{z}_{A}}') == A.z
assert BaseScalar('A.x', 0, A, 'A_x',
r'\mathbf{{x}_{A}}').__hash__() == A.x.__hash__()
assert isinstance(A.x, BaseScalar) and \
isinstance(A.y, BaseScalar) and \
isinstance(A.z, BaseScalar)
assert A.x * A.y == A.y * A.x
assert A.scalar_map(A) == {A.x: A.x, A.y: A.y, A.z: A.z}
assert A.x.system == A
assert A.x.diff(A.x) == 1
B = A.orient_new_axis('B', q, A.k)
assert B.scalar_map(A) == {
B.z: A.z,
B.y: -A.x * sin(q) + A.y * cos(q),
B.x: A.x * cos(q) + A.y * sin(q)
}
assert A.scalar_map(B) == {
A.x: B.x * cos(q) - B.y * sin(q),
A.y: B.x * sin(q) + B.y * cos(q),
A.z: B.z
}
assert express(B.x, A, variables=True) == A.x * cos(q) + A.y * sin(q)
assert express(B.y, A, variables=True) == -A.x * sin(q) + A.y * cos(q)
assert express(B.z, A, variables=True) == A.z
assert expand(express(B.x*B.y*B.z, A, variables=True)) == \
expand(A.z*(-A.x*sin(q) + A.y*cos(q))*(A.x*cos(q) + A.y*sin(q)))
assert express(B.x*B.i + B.y*B.j + B.z*B.k, A) == \
(B.x*cos(q) - B.y*sin(q))*A.i + (B.x*sin(q) + \
B.y*cos(q))*A.j + B.z*A.k
assert simplify(express(B.x*B.i + B.y*B.j + B.z*B.k, A, \
variables=True)) == \
A.x*A.i + A.y*A.j + A.z*A.k
assert express(A.x*A.i + A.y*A.j + A.z*A.k, B) == \
(A.x*cos(q) + A.y*sin(q))*B.i + \
(-A.x*sin(q) + A.y*cos(q))*B.j + A.z*B.k
assert simplify(express(A.x*A.i + A.y*A.j + A.z*A.k, B, \
variables=True)) == \
B.x*B.i + B.y*B.j + B.z*B.k
N = B.orient_new_axis('N', -q, B.k)
assert N.scalar_map(A) == \
{N.x: A.x, N.z: A.z, N.y: A.y}
C = A.orient_new_axis('C', q, A.i + A.j + A.k)
mapping = A.scalar_map(C)
assert mapping[A.x].equals(C.x * (2 * cos(q) + 1) / 3 + C.y *
(-2 * sin(q + pi / 6) + 1) / 3 + C.z *
(-2 * cos(q + pi / 3) + 1) / 3)
assert mapping[A.y].equals(C.x * (-2 * cos(q + pi / 3) + 1) / 3 + C.y *
(2 * cos(q) + 1) / 3 + C.z *
(-2 * sin(q + pi / 6) + 1) / 3)
assert mapping[A.z].equals(C.x * (-2 * sin(q + pi / 6) + 1) / 3 + C.y *
(-2 * cos(q + pi / 3) + 1) / 3 + C.z *
(2 * cos(q) + 1) / 3)
D = A.locate_new('D', a * A.i + b * A.j + c * A.k)
assert D.scalar_map(A) == {D.z: A.z - c, D.x: A.x - a, D.y: A.y - b}
E = A.orient_new_axis('E', a, A.k, a * A.i + b * A.j + c * A.k)
assert A.scalar_map(E) == {
A.z: E.z + c,
A.x: E.x * cos(a) - E.y * sin(a) + a,
A.y: E.x * sin(a) + E.y * cos(a) + b
}
assert E.scalar_map(A) == {
E.x: (A.x - a) * cos(a) + (A.y - b) * sin(a),
E.y: (-A.x + a) * sin(a) + (A.y - b) * cos(a),
E.z: A.z - c
}
F = A.locate_new('F', Vector.zero)
assert A.scalar_map(F) == {A.z: F.z, A.x: F.x, A.y: F.y}
from sympy.simplify import simplify, trigsimp
from sympy import pi, sqrt, symbols, ImmutableMatrix as Matrix, sin, cos
from sympy.vector.vector import Vector, BaseVector, VectorAdd, VectorMul, VectorZero
from sympy.vector.coordsysrect import CoordSysCartesian
C = CoordSysCartesian("C")
i, j, k = C.base_vectors()
a, b, c = symbols("a b c")
def test_vector_sympy():
"""
Test whether the Vector framework confirms to the hashing
and equality testing properties of SymPy.
"""
i1 = BaseVector("i1", 0, C)
assert i1 == i
assert i1.__hash__() == i.__hash__()
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_vector():
assert isinstance(i, BaseVector)
assert i != j
def test_evalf():
A = CoordSysCartesian('A')
v = 3 * A.i + 4 * A.j + a * A.k
assert v.n() == v.evalf()
assert v.evalf(subs={a: 1}) == v.subs(a, 1).evalf()
from sympy.vector.vector import Vector
from sympy.vector.coordsysrect import CoordSysCartesian
from sympy.simplify import simplify
from sympy.core.symbol import symbols
from sympy.core import S
from sympy import sin, cos
C = CoordSysCartesian('C')
i, j, k = C.base_vectors()
x, y, z = C.base_scalars()
delop = C.delop
a, b, c = symbols('a b c')
def test_del_operator():
#Tests for curl
assert delop ^ Vector.zero == Vector.zero
assert delop.cross(Vector.zero) == Vector.zero
assert delop ^ i == Vector.zero
assert delop.cross(2*y**2*j) == Vector.zero
v = x*y*z * (i + j + k)
assert delop ^ v == \
(-x*y + x*z)*i + (x*y - y*z)*j + (-x*z + y*z)*k
assert delop ^ v == delop.cross(v)
assert delop.cross(2*x**2*j) == 4*x*k
#Tests for divergence
assert delop & Vector.zero == S(0)
assert delop.dot(Vector.zero) == S(0)
assert delop & i == S(0)
assert delop & x**2*i == 2*x
from sympy.simplify import simplify, trigsimp
from sympy import pi, sqrt, symbols, ImmutableMatrix as Matrix, \
sin, cos, Function, Integral, Derivative, diff, integrate
from sympy.vector.vector import Vector, BaseVector, VectorAdd, \
VectorMul, VectorZero
from sympy.vector.coordsysrect import CoordSysCartesian
C = CoordSysCartesian('C')
i, j, k = C.base_vectors()
a, b, c = symbols('a b c')
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_vector():
assert isinstance(i, BaseVector)
assert i != j
assert j != k
def test_coordinate_vars():
"""
Tests the coordinate variables functionality with respect to
reorientation of coordinate systems.
"""
A = CoordSysCartesian('A')
assert BaseScalar('Ax', 0, A, ' ', ' ') == A.x
assert BaseScalar('Ay', 1, A, ' ', ' ') == A.y
assert BaseScalar('Az', 2, A, ' ', ' ') == A.z
assert BaseScalar('Ax', 0, A, ' ', ' ').__hash__() == A.x.__hash__()
assert isinstance(A.x, BaseScalar) and \
isinstance(A.y, BaseScalar) and \
isinstance(A.z, BaseScalar)
assert A.scalar_map(A) == {A.x: A.x, A.y: A.y, A.z: A.z}
assert A.x.system == A
B = A.orient_new_axis('B', q, A.k)
assert B.scalar_map(A) == {B.z: A.z, B.y: -A.x*sin(q) + A.y*cos(q),
B.x: A.x*cos(q) + A.y*sin(q)}
assert A.scalar_map(B) == {A.x: B.x*cos(q) - B.y*sin(q),
A.y: B.x*sin(q) + B.y*cos(q), A.z: B.z}
assert express(B.x, A, variables=True) == A.x*cos(q) + A.y*sin(q)
assert express(B.y, A, variables=True) == -A.x*sin(q) + A.y*cos(q)
assert express(B.z, A, variables=True) == A.z
assert express(B.x*B.y*B.z, A, variables=True) == \
A.z*(-A.x*sin(q) + A.y*cos(q))*(A.x*cos(q) + A.y*sin(q))
assert express(B.x*B.i + B.y*B.j + B.z*B.k, A) == \
(B.x*cos(q) - B.y*sin(q))*A.i + (B.x*sin(q) + \
B.y*cos(q))*A.j + B.z*A.k
assert simplify(express(B.x*B.i + B.y*B.j + B.z*B.k, A, \
variables=True)) == \
A.x*A.i + A.y*A.j + A.z*A.k
assert express(A.x*A.i + A.y*A.j + A.z*A.k, B) == \
(A.x*cos(q) + A.y*sin(q))*B.i + \
(-A.x*sin(q) + A.y*cos(q))*B.j + A.z*B.k
assert simplify(express(A.x*A.i + A.y*A.j + A.z*A.k, B, \
variables=True)) == \
B.x*B.i + B.y*B.j + B.z*B.k
N = B.orient_new_axis('N', -q, B.k)
assert N.scalar_map(A) == \
{N.x: A.x, N.z: A.z, N.y: A.y}
C = A.orient_new_axis('C', q, A.i + A.j + A.k)
mapping = A.scalar_map(C)
assert mapping[A.x] == 2*C.x*cos(q)/3 + C.x/3 - \
2*C.y*sin(q + pi/6)/3 + C.y/3 - 2*C.z*cos(q + pi/3)/3 + C.z/3
assert mapping[A.y] == -2*C.x*cos(q + pi/3)/3 + \
C.x/3 + 2*C.y*cos(q)/3 + C.y/3 - 2*C.z*sin(q + pi/6)/3 + C.z/3
assert mapping[A.z] == -2*C.x*sin(q + pi/6)/3 + C.x/3 - \
2*C.y*cos(q + pi/3)/3 + C.y/3 + 2*C.z*cos(q)/3 + C.z/3
D = A.locate_new('D', a*A.i + b*A.j + c*A.k)
assert D.scalar_map(A) == {D.z: A.z - c, D.x: A.x - a, D.y: A.y - b}
E = A.orient_new_axis('E', a, A.k, a*A.i + b*A.j + c*A.k)
assert A.scalar_map(E) == {A.z: E.z + c,
A.x: E.x*cos(a) - E.y*sin(a) + a,
A.y: E.x*sin(a) + E.y*cos(a) + b}
assert E.scalar_map(A) == {E.x: (A.x - a)*cos(a) + (A.y - b)*sin(a),
E.y: (-A.x + a)*sin(a) + (A.y - b)*cos(a),
E.z: A.z - c}
F = A.locate_new('F', Vector.zero)
assert A.scalar_map(F) == {A.z: F.z, A.x: F.x, A.y: F.y}
from sympy.core.function import Derivative
from sympy.vector.vector import Vector
from sympy.vector.coordsysrect import CoordSysCartesian
from sympy.simplify import simplify
from sympy.core.symbol import symbols
from sympy.core import S
from sympy import sin, cos
from sympy.vector.functions import (curl, divergence, gradient,
is_conservative, is_solenoidal,
scalar_potential,
scalar_potential_difference)
from sympy.utilities.pytest import raises
C = CoordSysCartesian('C')
i, j, k = C.base_vectors()
x, y, z = C.base_scalars()
delop = C.delop
a, b, c, q = symbols('a b c q')
def test_del_operator():
#Tests for curl
assert (delop ^ Vector.zero ==
(Derivative(0, C.y) - Derivative(0, C.z))*C.i +
(-Derivative(0, C.x) + Derivative(0, C.z))*C.j +
(Derivative(0, C.x) - Derivative(0, C.y))*C.k)
assert ((delop ^ Vector.zero).doit() == Vector.zero ==
curl(Vector.zero, C))
assert delop.cross(Vector.zero) == delop ^ Vector.zero
assert (delop ^ i).doit() == Vector.zero
assert delop.cross(2*y**2*j, doit = True) == Vector.zero
def test_rotation_matrix():
N = CoordSysCartesian("N")
A = N.orient_new_axis("A", q1, N.k)
B = A.orient_new_axis("B", q2, A.i)
C = B.orient_new_axis("C", q3, B.j)
D = N.orient_new_axis("D", q4, N.j)
E = N.orient_new_space("E", q1, q2, q3, "123")
F = N.orient_new_quaternion("F", q1, q2, q3, q4)
G = N.orient_new_body("G", q1, q2, q3, "123")
assert N.rotation_matrix(C) == Matrix(
[
[
-sin(q1) * sin(q2) * sin(q3) + cos(q1) * cos(q3),
-sin(q1) * cos(q2),
sin(q1) * sin(q2) * cos(q3) + sin(q3) * cos(q1),
],
[
sin(q1) * cos(q3) + sin(q2) * sin(q3) * cos(q1),
cos(q1) * cos(q2),
sin(q1) * sin(q3) - sin(q2) * cos(q1) * cos(q3),
],
[-sin(q3) * cos(q2), sin(q2), cos(q2) * cos(q3)],
]
)
test_mat = D.rotation_matrix(C) - Matrix(
[
[
cos(q1) * cos(q3) * cos(q4) - sin(q3) * (-sin(q4) * cos(q2) + sin(q1) * sin(q2) * cos(q4)),
-sin(q2) * sin(q4) - sin(q1) * cos(q2) * cos(q4),
sin(q3) * cos(q1) * cos(q4) + cos(q3) * (-sin(q4) * cos(q2) + sin(q1) * sin(q2) * cos(q4)),
],
[
sin(q1) * cos(q3) + sin(q2) * sin(q3) * cos(q1),
cos(q1) * cos(q2),
sin(q1) * sin(q3) - sin(q2) * cos(q1) * cos(q3),
],
[
sin(q4) * cos(q1) * cos(q3) - sin(q3) * (cos(q2) * cos(q4) + sin(q1) * sin(q2) * sin(q4)),
sin(q2) * cos(q4) - sin(q1) * sin(q4) * cos(q2),
sin(q3) * sin(q4) * cos(q1) + cos(q3) * (cos(q2) * cos(q4) + sin(q1) * sin(q2) * sin(q4)),
],
]
)
assert test_mat.expand() == zeros(3, 3)
assert E.rotation_matrix(N) == Matrix(
[
[cos(q2) * cos(q3), sin(q3) * cos(q2), -sin(q2)],
[
sin(q1) * sin(q2) * cos(q3) - sin(q3) * cos(q1),
sin(q1) * sin(q2) * sin(q3) + cos(q1) * cos(q3),
sin(q1) * cos(q2),
],
[
sin(q1) * sin(q3) + sin(q2) * cos(q1) * cos(q3),
-sin(q1) * cos(q3) + sin(q2) * sin(q3) * cos(q1),
cos(q1) * cos(q2),
],
]
)
assert F.rotation_matrix(N) == Matrix(
[
[q1 ** 2 + q2 ** 2 - q3 ** 2 - q4 ** 2, 2 * q1 * q4 + 2 * q2 * q3, -2 * q1 * q3 + 2 * q2 * q4],
[-2 * q1 * q4 + 2 * q2 * q3, q1 ** 2 - q2 ** 2 + q3 ** 2 - q4 ** 2, 2 * q1 * q2 + 2 * q3 * q4],
[2 * q1 * q3 + 2 * q2 * q4, -2 * q1 * q2 + 2 * q3 * q4, q1 ** 2 - q2 ** 2 - q3 ** 2 + q4 ** 2],
]
)
assert G.rotation_matrix(N) == Matrix(
[
[
cos(q2) * cos(q3),
sin(q1) * sin(q2) * cos(q3) + sin(q3) * cos(q1),
sin(q1) * sin(q3) - sin(q2) * cos(q1) * cos(q3),
],
[
-sin(q3) * cos(q2),
-sin(q1) * sin(q2) * sin(q3) + cos(q1) * cos(q3),
sin(q1) * cos(q3) + sin(q2) * sin(q3) * cos(q1),
],
[sin(q2), -sin(q1) * cos(q2), cos(q1) * cos(q2)],
]
)
def test_coordsys3d():
with warns_deprecated_sympy():
assert CoordSysCartesian("C") == CoordSys3D("C")
def test_lame_coefficients():
a = CoordSysCartesian('a')
a._set_lame_coefficient_mapping('spherical')
assert a.lame_coefficients() == (1, a.x, sin(a.y) * a.x)
a = CoordSysCartesian('a')
assert a.lame_coefficients() == (1, 1, 1)
a = CoordSysCartesian('a')
a._set_lame_coefficient_mapping('cartesian')
assert a.lame_coefficients() == (1, 1, 1)
a = CoordSysCartesian('a')
a._set_lame_coefficient_mapping('cylindrical')
assert a.lame_coefficients() == (1, a.y, 1)
