system = SurfaceGuidedMassSystem(
surface=sphere,
s0=np.array([np.pi/2, 1.0, np.pi/2, 0.0]),
m=m,
forces=[
Gravity(m=m, g=g),
SpringForce(stiffness=k, clip=clip),
# ViscousFriction(mu=0.2),
]
)
# simulate
time = np.linspace(0, 20, 5000)
states = system.solve(time)
# build (todo opti)
mesh = sphere.build_surface(*sphere.mesh(50, 50))
physics = system.solutions(states, time)
trajectory = physics[:, Pi]
speed = physics[:, Vi]
abs_speed = physics[:, nVi]
Ec = 0.5 * m * abs_speed**2
Epk = np.zeros_like(Ec)
for i in range(len(trajectory)):
Epk[i] = 0.5*k*np.linalg.norm(trajectory[i] - clip, 2)**2
from gsurface import Plan, SurfaceGuidedMassSystem, build_s0
from gsurface.forces import CenterDirectedViscousFriction, ConstantDirectedViscousFriction
from gsurface.forces import SpringDampingForce
from gsurface.plotter import mayavi_plot_surfaces, SurfacePlot, Tyi
# simulate a 2D spring damping system, we notice that the radial speed tends to 0 where rotational speed still constant
plan = Plan(a=0.0, c=1.0)
surface = plan.build_surface(*plan.mesh(50, 50))
model = SurfaceGuidedMassSystem(surface=plan,
s0=build_s0(u0=0.5, du0=0.0, dv0=5),
m=1.0,
forces=[
ConstantDirectedViscousFriction(
1.0, np.array([1.0, 0.0, 0.0])),
CenterDirectedViscousFriction(1.0),
SpringDampingForce(100.0, 1.0, None, 1.0)
])
time = np.linspace(0, 10, 3000)
data = model.solve(time)
solutions = model.solutions(data, time)
mayavi_plot_surfaces([SurfacePlot(surface, trajectory=solutions[Tyi])])
from gsurface.serialize import save_attached
model_parsed = save_attached(model, __file__)
import numpy as np
from gsurface import SurfaceGuidedMassSystem, build_s0
from gsurface.forces import Gravity, SpringForce, ViscousFriction
from gsurface.plotter import mayavi_plot_surfaces, SurfacePlot, Tyi
from gsurface.surface import Cylinder
mass = 1.0 # kg
system = SurfaceGuidedMassSystem(
surface=Cylinder(R=1.0).setlims(v_ll=-1, v_ul=1),
solid=mass,
forces=Gravity(mass, g=np.array([0.0, 0.0, -1.0])) +
SpringForce(stiffness=1.0, clip=np.array([-0.5, 0.0, 0.0])) +
ViscousFriction(0.1),
s0=build_s0(0, 0.5, 0, 0),
)
time = np.linspace(0, 50.0, 1000)
data = system.solve(time)
solutions = system.solutions(data, time)
smesh = system.surface.build_surface(*system.surface.mesh(40, 40))
mayavi_plot_surfaces(
[SurfacePlot(smesh, showSurface=True, trajectory=solutions[Tyi])])