def __init__(self,
size,
t_refractory=1.,
V_rest=0.,
V_reset=-5.,
V_th=20.,
R=1.,
tau=10.,
has_noise=True,
**kwargs):
# parameters
self.V_rest = V_rest
self.V_reset = V_reset
self.V_th = V_th
self.R = R
self.tau = tau
self.t_refractory = t_refractory
# variables
self.t_last_spike = bp.ops.ones(size) * -1e7
self.refractory = bp.ops.zeros(size)
self.input = bp.ops.zeros(size)
self.spike = bp.ops.zeros(size)
self.V = bp.ops.ones(size) * V_reset
if has_noise:
self.int_V = bp.sdeint(f=self.f_v, g=self.g_v)
else:
self.int_V = bp.odeint(f=self.f_v)
super(StochasticLIF, self).__init__(size=size, **kwargs)
def test_sde():
def lorenz_g(x, y, z, t, sigma=10, beta=8 / 3, rho=28, p=0.1):
return p * x, p * y, p * z
def lorenz_f(x, y, z, t, sigma=10, beta=8 / 3, rho=28, p=0.1):
dx = sigma * (y - x)
dy = x * (rho - z) - y
dz = x * y - beta * z
return dx, dy, dz
# for method in euler_and_milstein.__all__:
for method in ['euler', 'milstein']:
for sde_type in bp.SUPPORTED_SDE_TYPE:
if method == 'heun' and sde_type == bp.ITO_SDE:
continue
for var_type in bp.SUPPORTED_VAR_TYPE:
for wiener_type in bp.SUPPORTED_WIENER_TYPE:
print(
f'"{method}" method, "{sde_type}" sde type, '
f'"{var_type}" var type, "{wiener_type}" wiener type:')
bp.sdeint(f=lorenz_f,
g=lorenz_g,
show_code=True,
method=method,
var_type=var_type,
sde_type=sde_type,
wiener_type=wiener_type)
print()
for method in [
'exponential_euler', 'srk1w1_scalar', 'srk2w1_scalar',
'KlPl_scalar'
]:
for var_type in bp.SUPPORTED_VAR_TYPE:
for wiener_type in bp.SUPPORTED_WIENER_TYPE:
with pytest.raises(bp.errors.IntegratorError):
bp.sdeint(f=lorenz_f,
g=lorenz_g,
show_code=True,
method=method,
var_type=var_type,
sde_type=bp.STRA_SDE,
wiener_type=wiener_type)
def test_sde():
def lorenz_g(x, y, z, t, sigma=10, beta=8 / 3, rho=28, p=0.1):
return p * x, p * y, p * z
def lorenz_f(x, y, z, t, sigma=10, beta=8 / 3, rho=28, p=0.1):
dx = sigma * (y - x)
dy = x * (rho - z) - y
dz = x * y - beta * z
return dx, dy, dz
# for method in euler_and_milstein.__all__:
for method in ['milstein', ]:
for sde_type in [bp.ITO_SDE, bp.STRA_SDE]:
print(f'{sde_type} type, {method} method:')
bp.sdeint(f=lorenz_f, g=lorenz_g, show_code=True, method=method,
var_type=bp.SCALAR_VAR, sde_type=sde_type)
print()
for method in ['euler', 'exponential_euler']:
sde_type = bp.ITO_SDE
print(f'{sde_type} type, {method} method:')
bp.sdeint(f=lorenz_f, g=lorenz_g, show_code=True, method=method,
var_type=bp.SCALAR_VAR, sde_type=sde_type)
print()
for method in ['heun']:
sde_type = bp.STRA_SDE
print(f'{sde_type} type, {method} method:')
bp.sdeint(f=lorenz_f, g=lorenz_g, show_code=True, method=method,
var_type=bp.SCALAR_VAR, sde_type=sde_type)
print()
def __init__(cls, size, t_refractory=1., V_rest=0.,
V_reset=-5., V_th=20., R=1., tau=10., **kwargs):
# parameters
cls.V_rest = V_rest
cls.V_reset = V_reset
cls.V_th = V_th
cls.R = R
cls.tau = tau
cls.t_refractory = t_refractory
# variables
cls.t_last_spike = bp.ops.ones(size) * -1e7
cls.refractory = bp.ops.zeros(size)
cls.input = bp.ops.zeros(size)
cls.spike = bp.ops.zeros(size)
cls.V = bp.ops.ones(size) * V_reset
cls.int_V = bp.sdeint(f=cls.f_v, g=cls.g_v)
super(LIF, cls).__init__(size=size, **kwargs)