无法合并输出中的列表

问题描述

我有以下程序，看来末尾的放大器和周期会打印出一个列表清单（见下文）。而且我无法绘制它们（我想绘制相对于放大器的周期）

我已经尝试过How to make a flat list out of list of lists?中的方法来组合amp和period的输出，以便它们可以绘制图表，但是没有用。

import numpy as np
import matplotlib.pyplot as plt
from scipy.integrate import solve_ivp

def derivatives(t,y,q,F):
    return [y[1],-np.sin(y[0])-q*y[1]+F*np.sin((2/3)*t)]

t = np.linspace(0.0,100,10000)

#initial conditions
theta0 = np.linspace(0.0,np.pi,100)
q = 0.0       #alpha / (mass*g),resistive term
F = 0.0       #G*np.sin(2*t/3)

for i in range (0,100):
    sol = solve_ivp(derivatives,(0.0,100.0),(theta0[i],0.0),method = 'RK45',t_eval = t,args = (q,F))

    velocity = sol.y[1]
    time = sol.t

    zero_cross = 0
    value = []
    amp = []
    period = []

    for k in range (len(velocity)-1):
        if (velocity[k+1]*velocity[k]) < 0:
            zero_cross += 1
            value.append(k)
        else:
            zero_cross += 0

    zero_cross = zero_cross - zero_cross % 2         # makes the total number of zero-crossings even

    if zero_cross != 0:
        amp.append(theta0[i])
      # period calculated using the time evolved between the first and last zero-crossing detected
        period.append((2*(time[value[zero_cross - 1]] - time[value[0]])) / (zero_cross -1))

如果我在回路内打印出放大器，它将显示如下：

[0.03173325912716963]
[0.06346651825433926]
[0.0951997773815089]
[0.12693303650867852]
[0.15866629563584814]
[0.1903995547630178]
[0.2221328138901874]
[0.25386607301735703]
[0.28559933214452665]
[0.3173325912716963]
[0.3490658503988659]
[0.3807991095260356]
[0.4125323686532052]
[0.4442656277803748]
[0.47599888690754444]
[0.5077321460347141]
[0.5394654051618837]
[0.5711986642890533]
[0.6029319234162229]
[0.6346651825433925]
[0.6663984416705622]
[0.6981317007977318]
[0.7298649599249014]
[0.7615982190520711]
[0.7933314781792408]
[0.8250647373064104]
[0.85679799643358]
[0.8885312555607496]
[0.9202645146879193]
[0.9519977738150889]
[0.9837310329422585]
[1.0154642920694281]
[1.0471975511965979]
[1.0789308103237674]
[1.110664069450937]
[1.1423973285781066]
[1.1741305877052763]
[1.2058638468324459]
[1.2375971059596156]
[1.269330365086785]
[1.3010636242139548]
[1.3327968833411243]
[1.364530142468294]
[1.3962634015954636]
[1.4279966607226333]
[1.4597299198498028]
[1.4914631789769726]
[1.5231964381041423]
[1.5549296972313118]
[1.5866629563584815]
[1.618396215485651]
[1.6501294746128208]
[1.6818627337399903]
[1.71359599286716]
[1.7453292519943295]
[1.7770625111214993]
[1.8087957702486688]
[1.8405290293758385]
[1.872262288503008]
[1.9039955476301778]
[1.9357288067573473]
[1.967462065884517]
[1.9991953250116865]
[2.0309285841388562]
[2.0626618432660258]
[2.0943951023931957]
[2.126128361520365]
[2.1578616206475347]
[2.1895948797747042]
[2.221328138901874]
[2.2530613980290437]
[2.284794657156213]
[2.3165279162833827]
[2.3482611754105527]
[2.379994434537722]
[2.4117276936648917]
[2.443460952792061]
[2.475194211919231]
[2.5069274710464007]
[2.53866073017357]
[2.57039398930074]
[2.6021272484279097]
[2.633860507555079]
[2.6655937666822487]
[2.6973270258094186]
[2.729060284936588]
[2.7607935440637577]
[2.792526803190927]
[2.824260062318097]
[2.8559933214452666]
[2.887726580572436]
[2.9194598396996057]
[2.9511930988267756]
[2.982926357953945]
[3.0146596170811146]
[3.141592653589793]
[Finished in 3.822s]

我不确定输出是什么类型以及如何处理，将不胜感激！

解决方法

您在循环内声明了列表，这意味着它们将在每次迭代时重置为空。考虑在循环之前声明amp，period以及任何应设置为空的数组（作为初始状态），例如：

#initialize arrays,executes only once before the loop
amp = []
period = []


for i in range (0,100):
    #your logic here,plus appending values to `amp` and `period`

#now `amp` and `period` should contain all desired values