相关疑难解决方法(0)

我正在使用随附的代码来集成Fitzhugh-Nagumo模型的一个版本：

from scipy.integrate import odeint
import numpy as np
import time

P = {'epsilon':0.1,
     'a1':1.0,
     'a2':1.0,
     'b':2.0,
     'c':0.2}

def fhn_rhs(V,t,P):
    u,v = V[0],V[1]
    u_t = u - u**3 - v
    v_t = P['epsilon']*(u - P['b']*v - P['c'])
    return np.stack((u_t,v_t))

def integrate(func,V0,t,args,step='RK4'):
    start = time.clock()
    P = args[0]
    result=[V0]
    for i,tmp in enumerate(t[1:]):
        result.append(RK4step(func,result[i],tmp,P,(t[i+1]-t[i])))
    print "Integration took ",time.clock() - start, " s"
    return np.array(result)


def RK4step(rhs,V,t,P,dt):
    k_1 = dt*rhs(V,t,P)
    k_2 = dt*rhs((V+(1.0/2.0)*k_1),t,P)
    k_3 = dt*rhs((V+(1.0/2.0)*k_2),t,P)
    k_4 = dt*rhs((V+k_3),t,P)
    return …