def antikink_v0_95(): dx = 0.025 xLim = [-60,0] M = int((xLim[1] - xLim[0])/dx) + 1 x = np.linspace(xLim[0],xLim[1],M) v0 = .95 x0 = -20 state = SG.kink(x,0,v0,x0,epsilon=-1) field = SG.SineGordon(timeStepFunc='eulerRobin', state=state) return field
xLim = [-40, 0] # x range
v0 = 0.875 # Antikink's initial velocity
x0 = -20 # Antikink's initial position
k = np.linspace(0, 0.2, 2001) # Values for the Robin boundary parameter
dk = k[1] - k[0]
print('dk', dk)
### Setup x grid
M = int((xLim[1] - xLim[0]) / dx) + 1
x = np.linspace(xLim[0], xLim[1], M)
### Run the time evolution for each value of k and save the resulting field
state = SG.kink(x, 0, v0, x0, -1)
field = SG.SineGordon(state)
for t in [1000]:
field.time_evolve('euler_robin',
t + abs(x0) / v0,
dt=dt,
k=k,
dirichletValue=2 * pi,
dynamicRange=True)
field.save(
f'v875Kinematics_k{len(k)}_t{t}_dx{str(dx)[2:]}_dt{str(dt)[2:]}_field.nc'
) # save field to disk
### Find the bound state eigenvalues associated with the solitons produced in the antikink/boundary collision
### Ignore any breathers with frequency > 0.999
fieldFileName = f'v875Kinematics_k{len(k)}_t1000_dx{str(dx)[2:]}_dt{str(dt)[2:]}_field.nc'
eigenFileName = f'v875Kinematics_k{len(k)}_t1000_dx{str(dx)[2:]}_dt{str(dt)[2:]}_eigenvalues.nc'
dt = 0.2
xLim = [-20, 0]
M = int((xLim[1] - xLim[0]) / dx) + 1
x = np.linspace(xLim[0], xLim[1], M)
v0 = np.array([0.4, 0.6, 0.8])
# v0 = 0.6
k = np.array([0, 0.2, 0.4, 0.6])
# k = 0.2
# v0, k = 0.6, 0.9
x0 = -10
state = SG.kink(x, 0, v0, x0, -1)
field = SG.SineGordon(timeStepFunc='eulerRobin', state=state)
### XXX: What if tFin could be a function of the paramters?
### so tFin = lambda v0, x0: x0/v0 + 200
field.time_evolve(tFin=150,
dt=dt,
k=k,
dirichletValue=2 * pi,
dynamicRange=True)
vRange = [-0.95, 0]
eigenvalues = field.boundStateEigenvalues(vRange,
selection={
'v': 1,
'k': 1
},
dt = 0.002
xLim = [-40, 0] # x range
v0 = 0.95 # Antikink's initial velocity
x0 = -20 # Antikink's initial position
k = np.linspace(0.06, 0.075, 7501) # Values for the Robin boundary parameter
print('dk', k[1] - k[0])
### Setup spatial grid
M = int((xLim[1] - xLim[0]) / dx) + 1
x = np.linspace(xLim[0], xLim[1], M)
### Run the time evolution and save the result ###
state = SG.kink(x, 0, v0, x0, -1)
field = SG.SineGordon(state)
tList = [
100
] # t=100 -> ~104 hours compute time! Hope to get this down in the future.
for t in tList:
field.time_evolve('euler_robin',
t + abs(x0) / v0,
dt=dt,
k=k,
dirichletValue=2 * pi,
asymptoticBoundary={'L': 2 * pi})
field.save(
f'v95Kinematics_k{len(k)}_t{t}_dx{str(dx)[2:]}_dt{str(dt)[2:]}_field.nc'
) # save field to disk
### Find the bound state eigenvalues associated with the solitons produced in the antikink/boundary collision
def tevolve(v, k):
state = SG.kink(x,0,v,x0,-1)
field = SG.SineGordon(state)
field.time_evolve('euler_robin', 100+abs(x0)/v, dt=dt, k=k, dirichletValue=2*pi, asymptoticBoundary={'L':2*pi},
progressBar=False)
return float(field.state['u'][{'x':-1}].data)