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- """Predefined R^n manifolds together with common coord. systems.
- Coordinate systems are predefined as well as the transformation laws between
- them.
- Coordinate functions can be accessed as attributes of the manifold (eg `R2.x`),
- as attributes of the coordinate systems (eg `R2_r.x` and `R2_p.theta`), or by
- using the usual `coord_sys.coord_function(index, name)` interface.
- """
- from typing import Any
- import warnings
- from sympy.core.symbol import (Dummy, symbols)
- from sympy.functions.elementary.miscellaneous import sqrt
- from sympy.functions.elementary.trigonometric import (acos, atan2, cos, sin)
- from .diffgeom import Manifold, Patch, CoordSystem
- __all__ = [
- 'R2', 'R2_origin', 'relations_2d', 'R2_r', 'R2_p',
- 'R3', 'R3_origin', 'relations_3d', 'R3_r', 'R3_c', 'R3_s'
- ]
- ###############################################################################
- # R2
- ###############################################################################
- R2 = Manifold('R^2', 2) # type: Any
- R2_origin = Patch('origin', R2) # type: Any
- x, y = symbols('x y', real=True)
- r, theta = symbols('rho theta', nonnegative=True)
- relations_2d = {
- ('rectangular', 'polar'): [(x, y), (sqrt(x**2 + y**2), atan2(y, x))],
- ('polar', 'rectangular'): [(r, theta), (r*cos(theta), r*sin(theta))],
- }
- R2_r = CoordSystem('rectangular', R2_origin, (x, y), relations_2d) # type: Any
- R2_p = CoordSystem('polar', R2_origin, (r, theta), relations_2d) # type: Any
- # support deprecated feature
- with warnings.catch_warnings():
- warnings.simplefilter("ignore")
- x, y, r, theta = symbols('x y r theta', cls=Dummy)
- R2_r.connect_to(R2_p, [x, y],
- [sqrt(x**2 + y**2), atan2(y, x)],
- inverse=False, fill_in_gaps=False)
- R2_p.connect_to(R2_r, [r, theta],
- [r*cos(theta), r*sin(theta)],
- inverse=False, fill_in_gaps=False)
- # Defining the basis coordinate functions and adding shortcuts for them to the
- # manifold and the patch.
- R2.x, R2.y = R2_origin.x, R2_origin.y = R2_r.x, R2_r.y = R2_r.coord_functions()
- R2.r, R2.theta = R2_origin.r, R2_origin.theta = R2_p.r, R2_p.theta = R2_p.coord_functions()
- # Defining the basis vector fields and adding shortcuts for them to the
- # manifold and the patch.
- R2.e_x, R2.e_y = R2_origin.e_x, R2_origin.e_y = R2_r.e_x, R2_r.e_y = R2_r.base_vectors()
- R2.e_r, R2.e_theta = R2_origin.e_r, R2_origin.e_theta = R2_p.e_r, R2_p.e_theta = R2_p.base_vectors()
- # Defining the basis oneform fields and adding shortcuts for them to the
- # manifold and the patch.
- R2.dx, R2.dy = R2_origin.dx, R2_origin.dy = R2_r.dx, R2_r.dy = R2_r.base_oneforms()
- R2.dr, R2.dtheta = R2_origin.dr, R2_origin.dtheta = R2_p.dr, R2_p.dtheta = R2_p.base_oneforms()
- ###############################################################################
- # R3
- ###############################################################################
- R3 = Manifold('R^3', 3) # type: Any
- R3_origin = Patch('origin', R3) # type: Any
- x, y, z = symbols('x y z', real=True)
- rho, psi, r, theta, phi = symbols('rho psi r theta phi', nonnegative=True)
- relations_3d = {
- ('rectangular', 'cylindrical'): [(x, y, z),
- (sqrt(x**2 + y**2), atan2(y, x), z)],
- ('cylindrical', 'rectangular'): [(rho, psi, z),
- (rho*cos(psi), rho*sin(psi), z)],
- ('rectangular', 'spherical'): [(x, y, z),
- (sqrt(x**2 + y**2 + z**2),
- acos(z/sqrt(x**2 + y**2 + z**2)),
- atan2(y, x))],
- ('spherical', 'rectangular'): [(r, theta, phi),
- (r*sin(theta)*cos(phi),
- r*sin(theta)*sin(phi),
- r*cos(theta))],
- ('cylindrical', 'spherical'): [(rho, psi, z),
- (sqrt(rho**2 + z**2),
- acos(z/sqrt(rho**2 + z**2)),
- psi)],
- ('spherical', 'cylindrical'): [(r, theta, phi),
- (r*sin(theta), phi, r*cos(theta))],
- }
- R3_r = CoordSystem('rectangular', R3_origin, (x, y, z), relations_3d) # type: Any
- R3_c = CoordSystem('cylindrical', R3_origin, (rho, psi, z), relations_3d) # type: Any
- R3_s = CoordSystem('spherical', R3_origin, (r, theta, phi), relations_3d) # type: Any
- # support deprecated feature
- with warnings.catch_warnings():
- warnings.simplefilter("ignore")
- x, y, z, rho, psi, r, theta, phi = symbols('x y z rho psi r theta phi', cls=Dummy)
- R3_r.connect_to(R3_c, [x, y, z],
- [sqrt(x**2 + y**2), atan2(y, x), z],
- inverse=False, fill_in_gaps=False)
- R3_c.connect_to(R3_r, [rho, psi, z],
- [rho*cos(psi), rho*sin(psi), z],
- inverse=False, fill_in_gaps=False)
- ## rectangular <-> spherical
- R3_r.connect_to(R3_s, [x, y, z],
- [sqrt(x**2 + y**2 + z**2), acos(z/
- sqrt(x**2 + y**2 + z**2)), atan2(y, x)],
- inverse=False, fill_in_gaps=False)
- R3_s.connect_to(R3_r, [r, theta, phi],
- [r*sin(theta)*cos(phi), r*sin(
- theta)*sin(phi), r*cos(theta)],
- inverse=False, fill_in_gaps=False)
- ## cylindrical <-> spherical
- R3_c.connect_to(R3_s, [rho, psi, z],
- [sqrt(rho**2 + z**2), acos(z/sqrt(rho**2 + z**2)), psi],
- inverse=False, fill_in_gaps=False)
- R3_s.connect_to(R3_c, [r, theta, phi],
- [r*sin(theta), phi, r*cos(theta)],
- inverse=False, fill_in_gaps=False)
- # Defining the basis coordinate functions.
- R3_r.x, R3_r.y, R3_r.z = R3_r.coord_functions()
- R3_c.rho, R3_c.psi, R3_c.z = R3_c.coord_functions()
- R3_s.r, R3_s.theta, R3_s.phi = R3_s.coord_functions()
- # Defining the basis vector fields.
- R3_r.e_x, R3_r.e_y, R3_r.e_z = R3_r.base_vectors()
- R3_c.e_rho, R3_c.e_psi, R3_c.e_z = R3_c.base_vectors()
- R3_s.e_r, R3_s.e_theta, R3_s.e_phi = R3_s.base_vectors()
- # Defining the basis oneform fields.
- R3_r.dx, R3_r.dy, R3_r.dz = R3_r.base_oneforms()
- R3_c.drho, R3_c.dpsi, R3_c.dz = R3_c.base_oneforms()
- R3_s.dr, R3_s.dtheta, R3_s.dphi = R3_s.base_oneforms()
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