I am trying to solve an ODE with solve_ivp, but I am getting strange errors. Documentation: https://docs.scipy.org/doc/scipy/reference/generated/scipy.integrate.solve_ivp.html
from scipy.integrate import solve_ivp as solve import numpy as np import matplotlib.pyplot as plt def fun(t, y, beta, eps): u = 1/eps * (-1/3 * y**3 + y + y) v = beta - y y= u y= v return y eps = 0.05 beta = 1.1 y0 = np.array([2, 2]) t = np.linspace(0, 1000, num=10000) Y = solve(fun=lambda t, y: fun(t, y, beta, eps), t_span=(t,t[-1]), y0=y0 , method='RK45', t_eval=[1,2,3,4]).y
ValueError: need at least one array to concatenate
Note that I already had to deviate from the documentation, as args argument does not work either. Instead, I had to redefine my function which gets 2 additional arguments using the lambda method. I found this here: https://stackoverflow.com/questions/48245765/pass-args-for-solve-ivp-new-scipy-ode-api
Am I doing something wrong or is this method extremely buggy?