def __init__(self, pos, charge, mass, radius, color, vel, fixed,
negligible):
""" Creates a new particle with specified properties (in SI units)
pos: XYZ starting position of the particle, in meters
charge: charge of the particle, in Coulombs
mass: mass of the particle, in kg
radius: radius of the particle, in meters. No effect on simulation
color: color of the particle. If None, a default color will be chosen
vel: initial velocity vector, in m/s
fixed: if True, particle will remain fixed in place
negligible: assume charge is small wrt other charges to speed up calculation
"""
self.pos = vector(pos)
self.radius = radius
self.charge = charge
self.mass = mass
self.vel = vector(vel)
self.fixed = fixed
self.negligible = negligible
self.color = color
if vp:
self.vsphere = vp.add(Sphere(
pos, r=radius, c=color)) # Sphere representing the particle
# vp.addTrail(alpha=0.4, maxlength=1, n=50)
# Add a trail behind the particle
self.vsphere.addTrail(alpha=0.4, maxlength=1, n=50)
def __init__(self, songname=''):
self.KB = dict()
self.vp = None
self.rightHand = None
self.leftHand = None
self.vpRH = None
self.vpLH = None
self.playsounds = True
self.verbose = True
self.songname = songname
self.t0 = 0 # keep track of how many seconds to play
self.dt = 0.1
self.speedfactor = 1
self.engagedfingersR = [False] * 6 # element 0 is dummy
self.engagedfingersL = [False] * 6
self.engagedkeysR = []
self.engagedkeysL = []
self.tcoords = [
[-10., -15.], # texture
[11., -15.],
[-10., 16.],
[11., 16.],
[10., -15.],
[-11., -15.],
[10., 16.],
[-11., 16.],
[5., 10.],
[5., -11.],
[-6., 10.],
[-6., -11.],
[-5., 10.],
[-5., -11.],
[6., 10.],
[6., -11.],
[5., -15.],
[-6., -15.],
[5., 16.],
[-6., 16.],
[-5., -15.],
[6., -15.],
[-5., 16.],
[6., 16.]
]
self.tcoords = vector(self.tcoords) / 12 + 0.44
self.build_keyboard()
def simulate(self):
""" Runs the particle simulation. Simulates one time step, dt, of the particle motion.
Calculates the force between each pair of particles and updates particles' motion accordingly
"""
# Main simulation loop
for i in range(self.iterations):
for a in self.particles:
if a.fixed:
continue
ftot = vector(0, 0, 0) # total force acting on particle a
for b in self.particles:
if a.negligible and b.negligible or a == b:
continue
ab = a.pos - b.pos
ftot += ((K_COULOMB * a.charge * b.charge) /
mag2(ab)) * versor(ab)
a.vel += ftot / a.mass * self.dt # update velocity and position of a
a.pos += a.vel * self.dt
a.vsphere.pos(a.pos)
if vp:
vp.show(zoom=1.2)
vp.camera.Azimuth(0.1) # rotate camera
def simulate(self):
"""
Runs the particle simulation. Simulates one time step, dt, of the particle motion.
Calculates the force between each pair of particles and updates their motion accordingly
"""
# Main simulation loop
for i in range(self.iterations):
for a in self.particles:
if a.fixed:
continue
ftot = vector(0, 0, 0) # total force acting on particle a
for b in self.particles:
if a.negligible and b.negligible or a == b:
continue
ab = a.pos - b.pos
ftot += ((K_COULOMB * a.charge * b.charge) /
mag2(ab)) * versor(ab)
a.vel += ftot / a.mass * self.dt # update velocity and position of a
a.pos += a.vel * self.dt
a.vsphere.pos(a.pos)
if plt:
plt.show(resetcam=not i, azimuth=1)
if plt.escaped: break # if ESC is hit during the loop
x_dot[k] -= Dt * Ks * (bob_x_m[k] - bob_x_m[k + 1]) * factor
y_dot[k] -= Dt * Ks * (bob_y_m[k] - bob_y_m[k + 1]) * factor
# Check to see if they are colliding
for i in range(1, N):
for j in range(i + 1, N + 1):
dist2 = (bob_x[i] - bob_x[j])**2 + (bob_y[i] - bob_y[j])**2
if dist2 < DiaSq: # are colliding
Ddist = np.sqrt(dist2) - 2 * R
tau = versor([bob_x[j] - bob_x[i], bob_y[j] - bob_y[i], 0])
DR = Ddist / 2 * tau
bob_x[i] += DR[0] # DR.x
bob_y[i] += DR[1] # DR.y
bob_x[j] -= DR[0] # DR.x
bob_y[j] -= DR[1] # DR.y
Vji = vector(x_dot[j] - x_dot[i], y_dot[j] - y_dot[i])
DV = np.dot(Vji, tau) * tau
x_dot[i] += DV[0] # DV.x
y_dot[i] += DV[1] # DV.y
x_dot[j] -= DV[0] # DV.x
y_dot[j] -= DV[1] # DV.y
# Update the loations of the bobs and the stretching of the springs
for k in range(1, N + 1):
bob[k].pos([bob_x[k], bob_y[k], 0])
link[k - 1].stretch(bob[k - 1].pos(), bob[k].pos())
plt.show()
if plt.escaped: break # if ESC is hit during the loop
plt.close()